Hair color – what is it Hair

two black women straighten hair and natural curly hairHair fiber has no color, bleach any hair and the fiber looks white simply because it reflects light. Hair color is provided by pigments produced by cells called “melanocytes”. The pigments are called “melanin”. Melanin actually means black so strictly speaking we should only use this word when talking about black hair. However, today scientists and dermatologists use the word melanin when talking about any kind of hair pigment blonde, red, brown, or black.
In humans, melanocyte cells are found diffusely scattered in the skin and also in little clusters in the hair follicles. Melanocytes respond to various stimulants to produce more or less melanin. Sunlight exposure makes the melanocytes in the skin produce more pigment and we get a tan (unless you are of Celtic ancestry like me). In some other mammals, such as rats and mice, melanocytes are exclusively found located in hair follicles and not in the skin between the hair follicles. Rats and mice cannot get sun tans. But I digress. The melanocytes of the skin and the melanocytes of the hair follicles are essentially the same. It is thought that the melanocytes in hair follicles can act like a storage depot for supplying the skin with melanocytes. This becomes very apparent then the skin is damaged and depleted of melanocytes. Studies show the melanocyte cells migrate from the hair follicles to repopulate the melanocyte deficient skin.
Melanocytes in hair follicles are primarily located in the hair bulb at the bottom of hair follicles. They sit in a group just above the dermal papilla along with the matrix cells that produce the hair fiber. For the melanocytes, this is the ideal location to produce pigment and have it incorporated into the growing hair fiber. There are melanocytes located in other regions of the hair follicle such as the root sheaths that surround the hair fiber. However, it is thought that these melanocytes do not significantly contribute to coloring the hair fiber.
Melanocytes produce melanin pigment proteins in their cell cytoplasm. The pigment is accumulated in membrane bound vesicles in the cell called “melanosomes”. Melanocytes are usually very easy to identify in a skin biopsy because they are full of these melanosomes. In black hair producing follicles, the melanosomes in the melanocytes are very large oval shaped and gradually become densely filled with pigment proteins. People with lighter colored hair have less melanin protein in their melanosomes. Blonde haired people have melanosomes with a low density and patchy deposition of melanin. People with red and blonde hair have melanosomes that are smaller and spherical in shape and the individual melanin pigment granules inside the melanosomes are also smaller.
The matrix keratinocytes that produce the hair fiber cluster around the melanocyte cells. The melanocyte cells release their melanosomes to the keratinocytes through dendritic processes. The keratinocytes actively phagocytose the melanosomes (which means the keratinocytes “eat” the melanosomes by surrounding them and pulling them into the cell). Once the keratinocyte cells have melanosomes inside them they are then formed into the hair fiber and thus the hair fiber has color.
Hair color – biochemistry
In humans, all the different hair colors are due to just two types of pigment (melanin) called eumelanins and pheomelanins (European spelling, phaeomelanin). Eumelanins are the dark brown and black pigments while pheomelanins are the red and blonde pigments. The different colors of hair in different people are due to a combination of these two different basic biochemical structures. By mixing the two types together in different concentrations the many different shades of hair color are made.
Eumelanins are very strong, stable proteins made from tyrosine. The large eumelanin biochemical structure is formed by processing the amino acid tyrosine into dopa and dopamine and connecting several of these molecules together to form eumelanin. The key enzyme in this process is tyrosinase. The more tyrosinase activity the more eumelanin is formed. This is one method by which different people have different shades of brown to black hair color. More tyrosinase activity results in more pigment production and so a darker hair color. As we get older, tyrosinase activity increases. It is most active in middle age and thereafter tyrosinase activity decreases. There are also other biochemical mechanisms by which the shade of hair color is regulated. Several factors interact with tyrosinase to help regulate eumelanin production. In addition, another key limiting factor in hair color is the availability of the raw tyrosine ingredient. A lack of tyrosine availability means the tyrosinase enzyme make eumelanin at full capacity.
Pheomelanins are also made from the same tyrosine as eumelanins and the process is much the same with tyrosinase playing a key role. Pheomelanins are produced when an intermediate product in the eumelanin production pathway interacts with the amino acid cysteine. This results in the formation of a pheomelanin molecule which contains sulfur from the cysteine. These molecules are yellow to orange in color. So this is another way by which different shades of hair color can be produced. The more interaction there is between dopaquinone and cysteine the more yellow and orange pigments are produced.
Thus those people with darker hair have relatively more eumelanin production. People with true red hair produce more pheomelanin. The pathway to eumelanin formation is largely inhibited. Because people with red hair are less able to make the dark eumelanin pigment their skin is generally quite pale and burns easily with sun exposure. A study that analyzed the amount of eumelanin and pheomelanin in human hair suggested that; black hair contains approximately 99% eumelanin and 1% pheomelanin, brown and blond hair contain 95% eumelanin and 5% pheomelanin; and red hair contains 67% eumelanin and 33% pheomelanin (Borges 2001). Although people with dark hair may still produce the yellow – orange pheomelanin, it is largely masked by the dark eumelanin pigment and we cannot see much of it. However, the red – yellow pheomelanin is believed to cause the warm, golden, or auburn tones found in some types of brown hair.
How do we get all these different hair colours and shades
If you have read the pages Hair color – what is it and Hair color – biochemistry, you will have a good idea as to how we get so many different shades and colors of hair. Basically, the natural color of the hair is decided by, what type of melanin is in the hair, how much melanin is in the hair, and how densely packed the melanin is within the hair fiber.
So black hair is the result of a very high production of eumelanin which is very densely packed into the hair fiber. Brown hair comes in various shades and richness of color but basically brown haired people have a somewhat lower density of eumelanin in their hair fiber. The warmer, richer tones of brown hair are due to a greater presence of red – yellow pheomelanin. So the relative quantities of eumelanin versus pheomelanin in brown hair increase the heterogeneity of brown colored hair. Blonde haired people have eumelanin in their hair fiber as for black haired people, but the eumelanin is present at a very low density. Plain blonde hair is predominantly eumelanin while richer honey blonde hair has relatively more of the yellow red pheomelanin present. Red haired people have a high density of the pheomelanin pigments in their hair fiber. Those who produce virtually no eumelanin have a red to orange color depending on the density of the pigment in the hair fiber. Red haired people who have a greater relative proportion of eumelanin production have a deeper red to red brown color. Gray hair is essentially the result of reduced pigment production. The contrast between the hair with more color and the hair with less color, causes the appearance we call gray hair.
With so many different factors influencing hair color you might also be able to perceive why each individual may have hair fiber with different shades of the same basic color. Not all hair follicles are created exactly equal. While in one hair follicle there may be a little more eumelanin production or may pack a slightly higher density of melanin into the hair fiber, the hair follicle next door may not be quite so efficient. So when looking at individual hair fiber colors everyone sees some slight differences in the shade. So long as this variation is evenly distributed across the scalp we perceive one overall color when we look in the mirror. Only when a distinct area of follicles start producing more or less pigment do we identify that region as being a different color to the rest of the scalp hair.
Overall then there are many different interactions that lead to the subtle and not so subtle differences in hair color. Anthropologists and forensic scientists are most interested in this area and try to compare hair color between genetically distinct population to find identifying traits that can be exploited in their respective fields.
Why is hair coloured
Why do we have differences in hair color? In other mammals hair color is quite important for camouflage. Leopards’ spotted coats or tigers’ stripes blend into the background and thus helps with stalking prey. However, as a rule humans do not use their hair for camouflage.
To some extent hair color may help with protecting the skin from ultraviolet light damage. Dark skin protects from the damaging effects of UV light better than light skin. Not surprisingly, people with dark skin usually have dark hair too. The pigment in hair may protect the hair from weathering due to the effects of sunlight. However, hair of any color has an equal ability to protect the scalp from UV rays. It is the density of the hair that is important in skin protection rather than the hair color. Thus hair color in itself has little effect in skin protection.
Thus overall, hair color in humans is mostly due to the nature of the genetics that underlie skin color and the environmental factors that impacted on our ancestors. Pale skinned and thus blonde haired people live predominantly in the extreme north (e.g. Scandinavia) where limited sunlight exposure means not a lot of melanin is required. In contrast, dark skinned and thus dark haired people live close to the equator where pigment helps protect against UV damage to the skin. In the modern world where people can travel vast distances easily, these geographic distinctions in hair color break down, but in ancestral terms the principle is clear.
In humans today hair color plays a mostly psychological role – it is an indicator reproductive health and possibly a power display. In the same way that birds with brightly colored plumage attract a mate with displays of their eye catching colored feathers, so humans may attract mates based on their physical image. Hair and hair health is a particularly important feature in sexual attraction. As part of that, hair color may have a role. Apparently gentlemen prefer blondes.
Color may be an indicator of general health. Albinos mammals and birds are usually shunned by their peers and parents. In the wild they rarely survive for long. In human populations albinism is also a barrier to marriage and reproduction. In past times infanticide of albino babies was common.
A prime example of hair color used as a power display, the senior males in groups of mountain gorillas develop gray hair. The so called “silver backs”. This provides a very clear indicator of their power and leadership within the group. To some extent the same may be true for humans. Gray hair can be regarded as an indicator of wisdom. However, more commonly gray hair is taken as an indicator of age and reduced reproductive potential. The result being that many people dye their gray hair in an attempt to conceal their biological age.
Use of hair dye is primarily associated with sexual attraction, exhibitionism or in contrast, trying to blend in with their peers. Currently in Germany, red dyed hair for women is incredibly popular despite the fact that natural red hair in the German population is very rare – affecting less than 1% of the population. So on the one hand, German women want to stand out from the crowd with their red hair and on the other hand they are trying to conform to the image of their peers.

Environment, weathering and hair color changes
While the primary causes of hair color are due to our genes and their effects on the amount and type of melanin pigment production, there can also be changes in hair color due to environmental influences. The environment can affect hair in two ways, by physical action and by chemical reaction.
Chemical action on the hair is arguably becoming more of a problem with the increased frequency of chemical exposure that individuals encounter with modern living. Melanin pigment can be altered through interaction with acids and alkalis. Acid interaction darkens hair while alkali lightens hair color. Whether acid and alkali in air are present in high enough quantities to significantly interact with hair pigment remains to be determined, but acids and alkali are encountered in water supplies and as detergents in shampoos. Such exposure to acid and alkali solutions can affect hair color.
The effect of sunlight on hair can have a direct effect on color that may be accentuated in the presence of polluted air. With time, UV light degrades melanin pigment and bleaches the hair fiber. Black and dark brown hair may change into a lighter brown. Light brown and blonde hair can be bleached completely white with chronic sunlight exposure.
Hair color may seem to change as a result of physical actions on the hair or “weathering”. A healthy hair cuticle is fairly smooth and this gives hair a richer color. However, a poor cuticle is rough and flaky or sometimes the cuticle may be completely stripped away. This rough surface to the hair fiber results in much reflection and refraction of light. This gives an observer the impression that the hair color is lighter than it actually is. The color also has a dull dry appearance. Such physical weathering and consequent hair color changes most commonly occurs in people with heavily processed hair, those who use harsh detergents for washing, and those who excessively brush or otherwise manipulate their hair. In people with long hair the observer may see a color change from root to tip. The ends of the hair are the oldest hair and thus will be the most weathered hair. The hair roots are new hair and the cuticle here should be least damaged. As a result, the hair ends may seem to have a lighter color than the hair roots.
Bathing in salt water, whether it is sea water or high mineral salt containing tap water, can affect hair color. Whilst the salts dissolved in water might chemically interact with the pigment in hair, they may also affect the physical properties of the hair fiber. As hair washed in salt rich water dries out the salts may crystallize within the hair fiber and cuticle. This may physically break down the structural integrity of the hair and lift up the cuticle. The result may be weathered hair and an apparent reduction in hair color.
Some people are more susceptible to environment induced hair color changes than others as a result of secondary internal factors such as hormones and general genetic disposition. So while some people can wash their hair with strong alkali detergents with impunity, others with exactly the same hair color may find the same treatment significantly affects their hair color.

Environment, weathering and hair color changes
While the primary causes of hair color are due to our genes and their effects on the amount and type of melanin pigment production, there can also be changes in hair color due to environmental influences. The environment can affect hair in two ways, by physical action and by chemical reaction.
Chemical action on the hair is arguably becoming more of a problem with the increased frequency of chemical exposure that individuals encounter with modern living. Melanin pigment can be altered through interaction with acids and alkalis. Acid interaction darkens hair while alkali lightens hair color. Whether acid and alkali in air are present in high enough quantities to significantly interact with hair pigment remains to be determined, but acids and alkali are encountered in water supplies and as detergents in shampoos. Such exposure to acid and alkali solutions can affect hair color.
The effect of sunlight on hair can have a direct effect on color that may be accentuated in the presence of polluted air. With time, UV light degrades melanin pigment and bleaches the hair fiber. Black and dark brown hair may change into a lighter brown. Light brown and blonde hair can be bleached completely white with chronic sunlight exposure.
Hair color may seem to change as a result of physical actions on the hair or “weathering”. A healthy hair cuticle is fairly smooth and this gives hair a richer color. However, a poor cuticle is rough and flaky or sometimes the cuticle may be completely stripped away. This rough surface to the hair fiber results in much reflection and refraction of light. This gives an observer the impression that the hair color is lighter than it actually is. The color also has a dull dry appearance. Such physical weathering and consequent hair color changes most commonly occurs in people with heavily processed hair, those who use harsh detergents for washing, and those who excessively brush or otherwise manipulate their hair. In people with long hair the observer may see a color change from root to tip. The ends of the hair are the oldest hair and thus will be the most weathered hair. The hair roots are new hair and the cuticle here should be least damaged. As a result, the hair ends may seem to have a lighter color than the hair roots.
Bathing in salt water, whether it is sea water or high mineral salt containing tap water, can affect hair color. Whilst the salts dissolved in water might chemically interact with the pigment in hair, they may also affect the physical properties of the hair fiber. As hair washed in salt rich water dries out the salts may crystallize within the hair fiber and cuticle. This may physically break down the structural integrity of the hair and lift up the cuticle. The result may be weathered hair and an apparent reduction in hair color.
Some people are more susceptible to environment induced hair color changes than others as a result of secondary internal factors such as hormones and general genetic disposition. So while some people can wash their hair with strong alkali detergents with impunity, others with exactly the same hair color may find the same treatment significantly affects their hair color.
Abnormal increased hair pigmentation
Those people with light brown, red, or blonde hair probably noticed their hair color darkened by a few shades as they went through puberty. This is quite typical and is due to an increase in melanocyte pigment producing cell activity in response to the increased hormone levels. The change in hair color is apparently more significant on girls than boys perhaps suggesting that estrogens or progesterones have a more significant impact on pigment production. The key enzyme that helps produce melanin pigment, tyrosinase, is known to become more active as we get older. It is most active in middle age. The hair darkening effect also occurs in dark brown and black haired people too but because their hair is already highly pigmented a further increase in pigment production after puberty is much less noticeable.
Occasionally, some adults find that their hair color increases with age rather than the norm of progressive gray hair development. In some cases this can be related to the use of certain drugs. Cyclosporin, arsenic, levodopa or caridopa, bleomycin, daunorubicin and several chemotherapy drugs are known to increase hair pigmentation in some people. Several incidences of increases in hair pigmentation in those affected with Parkinson’s disease treated with dopamine related drugs have been reported. Various inflammatory skin diseases may also promote increased melanocyte activity within the inflamed area. A few people who develop alopecia areata and then have spontaneous regrowth sometimes regrow hair that is darker in color than it was before the alopecia areata. One of the most common disorders of skin hyperpigmentation is melasma. Occasionally this can also present with increased hair pigmentation too. This condition is predominantly seen in women and pregnancy is a frequent trigger for onset.
There have also been reports of apparently spontaneous reversal of gray hair and increases in hair color in the elderly as well as the development of new baby teeth (teeth and hair are similar structures). While these incidences have not been researched, it seems that with extreme age the factors regulating age entirely break down in some cells including melanocytes
Chemical induced hair color changes
There have been published reports of blonde hair turning green after prolonged exposure to chlorine in swimming pools. Sometimes darker hair can also develop a green tint to it. The problem is due to high concentrations of copper dissolved in the pool water. This can chemically interact with chlorine and the resulting chemical compound readily binds to the hair cuticle (Goldschmidt 1979, Goette 1978). It has also been reported that high levels of copper in tap water can also turn hair green (Goldschmidt 1979) and even copper in cosmetics containing plant extracts can be a risk (Tosti 1991). Iron dissolved in water can also turn blonde hair a murky brown color (Platschek 1989). Several options for treatment have been described for this problem, including application of hot vegetable oil, hydrogen peroxide, edetic acid- or D-penicillamine-containing shampoos, or hydroxyethyl diphosphonic acid (Mascaro 1995).
Of greater threat to health are the changes in hair color sometimes seen as a result of poisoning due to thallium or boron salts. High dose intake can be life threatening, but low dose intake produces more mild symptoms including a change in hair color. Sometimes the “flag” sign can be observed in mildly poisoned people. The flag sign is where hair fibers are depigmented along a portion of their length, but the roots and/or ends are fully pigmented. The loss of pigment in a portion of the hair fiber indicates temporary exposure to the poison equivalent to the length of depigmented hair produced.
Chronic smoking has been associated with premature gray hair (Mosely 1996). Presumably the toxic substances in tobacco smoke can block melanocyte cell pigment producing activity. Heavy smokers with white or gray hair may develop a yellow hair color. Most likely this occurs as a result of prolonged exposure to air laden with tar from cigarette smoke. The tar may chemically react with, and preferentially adhere to, the hair fiber. The only practical treatment is to avoid exposure to the toxic chemicals.
Drug induced hair color changes
Of pharmaceutical drugs, chloroquine and cancer chemotherapeutic agents are the most common cause of changes in hair color. Chemotherapeutic agents frequently cause hair loss, but in some people hair may not be lost but rather it changes color. People with dark hair seem to retain a greater concentration of chemotherapeutic agents within the hair fiber as compared to drug concentration in light colored hair. Whether this means dark hair is more prone to color changes is not known but it is a possibility.
Other drugs, such as alpha interferon, cyclosporin, p-aminobenzoic acid, calcium pantothenate, anthralin, chinoform, mephenesin, minoxidil, propofol, valproic acid, and verapamil have also been reported to promote hair color changes. This is not a comprehensive list of drugs that induce changes in hair color so if you suspect a drug induced hair color change, consult with your doctor.
Changes in hair color may be brought about by biochemical interaction within melanocyte cells in hair follicles either reducing or increasing pigment production. Drugs may also modify the mechanisms by which the pigment is incorporated into hair fibers. In addition, some drugs, such as minoxidil, may alter the physical properties of the hair and reduce or increase light reflectance. The amount of light reflected from hair can give the impression of a significant change in hair color to the observer.
Gray hair and age
The first onset of gray hair and the speed at which people go gray varies considerably from person to person. Most people actually start going gray in their late 20s but they don’t notice it immediately. Premature graying is defined as gray hair onset before late teens for Caucasians and before age 30 in Africans and Asians, or alternatively 50% or more gray scalp hair before age 50. Very occasionally, a few gray hairs can develop in children as young as 8 years and yet it indicates nothing other than an early onset of the gray hair that we all develop with increasing age. Typical gray hair first develops at age 34.2 +/- 9.6 years in Caucasians while for Black people the average age of onset is 43.9 +/-10.3 years (Keogh 1965). As a rough guide, 50% of the population in the US and Europe have 50% gray hair by age 50.
The most common areas on the scalp in which to first see gray hair development are above the ears and/or at the temples. This first gray hair may spread around the sides and to the crown with time. Gray hair development in the beard and mustache may also start quite early, while gray hair on the chest and pubic region generally only occurs some years after onset of gray hair on the scalp.
Gray hair is caused by the gradual reduction of melanin production over time within the affected hair follicle. The melanocytes in the hair follicles produce less and less melanin, and the result is a loss of hair fiber color strength. What we call gray hair is not gray at all if you look at the individual hair fibers. Some hair fibers will contain some color while others are virtually white. What we describe as gray comes about from our perception of the overall scalp hair color. The contrast between the hair with more color and the white hair causes the appearance we call gray hair. Thus two people with gray hair, standing side by side, may have different shades of gray. Blondes are most likely to develop a completely white head of hair in old age because their hair fiber has a very low density of pigment in it to start with.
The time and speed of gray hair onset is due in part to genetics. Certainly early onset gray hair development can run in families. In my own family women are invariably affected by early and rapid onset gray hair while men have a more typical gray hair development. This difference in gray hair development in my family might suggest that at least some of the genes that promote early gray hair onset are located on the X chromosome. However, there are most likely many genes that determine the time and speed of gray hair development located on several human chromosomes. What genes determine gray hair is not known and much research needs to be done in this area. The environment may also potentially modify gray hair development but there is effectively no research on this subject.
Nutrition and hair color
It is very rare to find nutritional factors as a cause of hair color changes. Any hair color changes due to nutritional deficiencies are typically only seen in people who have genetic defects, in diseases that block metabolism, or in severely malnourished individuals of the developing world.
Prolonged protein deficiency in the diet results in Kwashiorkor. This disease involves multiple symptoms including the reduction of pigment production and incorporation into hair fiber. Normally dark brown hair becomes a rusty red. Light colored hair becomes blonde. The flag sign sometimes seen in kwashiorkor involves alternating light and dark bands of color along individual hair fibers. The flag sign is associated with intermittent protein malnutrition. Presumably normal hair color is produced when protein intake is adequate and reduced hair color occurs during times when there is a lack of protein intake.
There may be a loss of hair (as well as skin and eye) color in individuals who have phenylketonuria. Lack of pigment in the hair is a minor concern with this condition as phenylketonuria typically involves significant mental retardation. This genetic disorder is caused by a deficiency of phenylalanine hydroxylase in the liver and this results in an inability to metabolize phenylalanine to tyrosine. Tyrosine is fundamentally required for pigment formation. Treatment involves taking tyrosine supplements and this can return hair color to normal in a short space of time.
Menkes’ kinky hair syndrome is a genetic disorder in which individuals are not able to properly absorb copper in the gut. Affected individuals have a variety of symptoms affecting the skin, hair, and central nervous system. The hair becomes progressively short, brittle, and kinked as the affected person gets older. Along with these changes in hair quality, the color gradually becomes lighter. Copper is a key component of the enzyme tyrosinase which is fundamentally required for processing tyrosine in pigment production so it is not surprising that copper deficiency leads to reduced hair pigmentation. Some affected individuals respond to subcutaneous administration of copper-histidinate with improvement in all symptoms including hair quality and color.
Celiac disease and other gut disorders that limit absorption may modify hair color and accelerate gray hair development in some. Severe vitamin B12 deficiency has been reported by some as a potential promoter of gray hair. Overall, it is extremely unusual to see hair color changes as a result of dietary deficiencies.
Albinism – oculocutaneous albinism
Albinism is actually a group of several subtly different conditions that have a hereditary error of melanin metabolism in common. Any genetic abnormality of the melanin pigment system in which the synthesis of melanin is reduced or absent can be called albinism. The reduction in melanin synthesis can affect the skin, hair follicles, and eyes, resulting in oculocutaneous albinism (OCA). If the skin and hair are normally pigmented and just the eye pigmentation is affected, the condition is called ocular albinism (OA).
There are two types of OCA, type I and type II. The classification of oculocutaneous albinism depends upon the nature of the underlying genetic defect. When a mutated tyrosinase gene produces inactive, less active, or temperature-sensitive tyrosinase, its phenotype is described as tyrosinase-negative (type I-A), yellow-mutant (type I-B), or temperature-sensitive (type I-TS) OCA, respectively. Mutation of the P gene encoding the tyrosine-transporting membrane protein probably occurs in tyrosinase-positive OCA (type II).
Oculocutaneous albinism type I is an autosomal recessive disorder characterized by absence of pigment in hair, skin, and eyes, and does not vary with race or age. Severe nystagmus, photophobia, and reduced visual acuity are common features. In contrast, the lack of pigmentation does not obstruct the normal growth and development of the skin or hair.
About 1 in 17,000 individuals in the United States have oculocutaneous albinism, and more than 1 per cent of the population are heterozygous for a gene producing albinism. The frequency varies with geographic region. In British Columbia, the frequency of oculocutaneous type I albinism is 1 in 67,800 and of type II albinism is 1 in 35,700. In Northern Ireland the frequency of type I albinism is 1 in 10,000. Famous albinos are believed to include Noah of flood fame and the Rev. Dr. Spooner. Spooner was a brilliant classicist at Oxford University whose amusing tendency to errors of speech came to be known as “spoonerisms”.
Albinism was one of the first genetic diseases to be identified in humans, but until quite recently little was known of the molecular mechanisms involved in its pathogenesis. Recent advances have shown us that mutations in at least seven separate genes can cause a reduction in melanin pigment biosynthesis, producing the various associated clinical features associated with albinism. However, there are at least 37 different genetic mutations (more than one mutation can occur in the same gene) defined that lead to OCA type I. There are probably more that have yet to be identified. Some geneticists have claimed there are over 60 different mutations. However, just 17 mutations account for over 90% of OCA type I affected individuals.
Albinism – Griscelli syndrome
One form of partial albinism associated with immunodeficiency in an individual is called Griscelli syndrome. This is a quite rare disorder that involves a lack of pigment production and a variable degree of immunodeficiency.
The common histopathology of Griscelli syndrome involves prominent, mature melanosomes in skin and hair follicle melanocytes, but sparse pigmentation of adjacent keratinocytes. This results in large, clumped melanosomes in hair shafts and as a result the hair has a silvery-gray sheen.
The associated immunodeficiency often involves impaired natural killer cell activity, absent delayed-type hypersensitivity, and a poor cell proliferation response to antigenic challenge. Occasionally, impaired lymphocyte function and and in inability to produce normal levels of immunoglobulins have also been described. The only treatment approach with any success is a bone marrow transplantation from a compatible donor. However, this has no effect on skin or hair color.

Albinism – Hermansky-Pudlak syndrome
Hermansky-Pudlak syndrome (HPS) is a rare disorder which has several features including; lack of hair, skin and eye color, prolonged bleeding, and problems with lysosomal ceroid storage. These symptoms occur due to defects in the melanosome, platelet-dense granule, and lysosome organelles of cells found in various cell types.
Hermansky-Pudlak syndrome is a genetic autosomal recessive disorder so it runs in families. There are 3 subtypes of Hermansky-Pudlak syndrome. HPS1 involves a mutation in the HPS1 gene on chromosome 10. HPS2 is caused by mutation in a gene on chromosome 5 encoding the beta-3A subunit of a protein complex called AP3. HPS3 involves a defect in a gene on chromosome 3.
Hermansky-Pudlak syndrome is probably the most common single gene disorder found in people of Puerto Rican ancestry. Hermansky-Pudlak syndrome has a frequency of about 1 in 1,800 Puerto Ricans which suggests that the frequency of Puerto Ricans carrying the gene is about 1 in 21 (Wildenberg 1995). Hermansky-Pudlak syndrome is also found in isolated pockets where the population is relatively inbred such as a mountain village high in the Swiss Alps (Schallreuter 1993).

Albinism – Chediak-Higashi syndrome
Chediak-Higashi syndrome (CHS) is a related disorder of Hermansky-Pudlak syndrome in which similar defects occur. However, this syndrome is different from Hermansky-Pudlack syndrome because there are significant changes in the numbers and activity of white blood cells. So the dominant feature of Chediak-Higashi syndrome is that affected individuals are immune deficient.
The symptoms include; a partial lack of hair, skin and eye color, increased susceptibility to infections, deficient natural killer cell activity, susceptibility to malignant lymphoma, and the presence of large intracytoplasmic granulations in various cell types. The symptoms are so severe that most people with Chediak-Higashi syndrome die at an early age.
Chediak-Higashi syndrome is a severe autosomal recessive immune deficiency disorder. There are at least 8 known gene allele defects that can cause Chediak-Higashi syndrome and it is quite possible that there are others that have yet to be identified. Chediak-Higashi syndrome arises due to an abnormal intracellular protein transport to, and from, the lysosome organelles in cells
Syndrome induced premature gray hair development
There are some syndromes with which early onset of gray hair has been associated. Those that are serious, such as progeria type syndromes, become apparent at any time from birth to puberty. Gray hair can be one of the visible symptoms, particularly in Werner’s syndrome, but much more serious symptoms are usually noticed first. These syndromes involve accelerated aging of the individual and children with these conditions have reduced life spans. Other syndromes with a serious impact on health that can occasionally involve premature gray hair development include Rothmund-Thomson syndrome and chromosome 5 syndrome (Cri du Chat syndrome).
An autosomal dominant genetic syndrome called Böök’s syndrome involves premature graying along with tooth development problems (teeth are very similar structures to hair follicles). Palmoplantar hyperhidrosis (sweaty hands and feet) is another symptom of Böök’s syndrome. It is a condition that runs in families with individuals affected to differing degrees.
Premature gray hair has also been associated with dyslexia in at least one study. What mechanism might be involved is entirely unknown, but hair follicles are responsive to neuroendocrine peptides produced by nerve cells and hair follicles are intimately enmeshed in a complex nerve cell network. Perhaps dyslexia is associated with a reduced ability of nerve cells to produce certain stimulatory products that may also affect hair follicle activity?
In addition to these syndromes inducing premature gray hair, disease may also promote hair color changes including gray hair. See; hair color changes secondary to disease for details

Hair color changes secondary to disease
There are many instances where a systemic disease can indirectly affect hair color. The mechanisms by which hair color changes occur in such diseases has not been investigated in any detail although various suggestions have been made.
Infection with HIV and subsequent development of AIDS can sometimes involve changes in hair color. This may be brought about perhaps though indirect effects of the immune system in hair follicle activity, but more likely the significant alterations in hormone levels, and nutritional deficiencies as progressive wasting occurs (effectively Kwashiorker), are the more likely causes.
Several studies have been conducted on the possible association of premature gray hair development and low bone mineral density (osteoporosis). The jury is still out on whether there is a true association. However, it is possible that low hormone levels associated with low bone density also affect melanocyte cell pigment producing activity. It is also possible that the melanocyte cells rely upon the activity of genes that are expressed in both bone mineral deposition and pigment production. If these genes are defective in some way, it may result in low bone mineral density and low pigment production.
Some research reports suggest an association between coronary artery disease and gray hair development. Autoimmune diseases that do not normally directly affect the skin, such as hypothyroidism, hyperthyroidism, and Addison’s pernicious anemia have been associated with gray hair development. Isolated case reports of hair color changes in association with other diseases and syndromes have also been reported.
Some genetic syndromes may result in premature gray hair development. See; syndrome induced premature gray hair for details.
Poliosis
Poliosis is the name given to a localized patch of white hair. Most frequently, poliosis presents as a white forelock, but it can involve a patch of white hair in normally pigmented hair anywhere on the body. Poliosis can occur in otherwise healthy people and may represent no more than an anomaly of hair and skin pigmentation.
However, poliosis is also observed in association with a wide variety of conditions. At the mild end of the spectrum, a minor genetic defect called piebaldism results in poliosis. Somewhat more significant, poliosis may be associated with pigmentary disturbances of the eye, as well as hair loss in hypogonadism and thyroid diseases.
Localized changes in the skin may also cause poliosis. Nevi and various kinds and focal skin cancers may result in patches of white hair growth in the areas of affected skin.
At the other end of the disease and disorder spectrum where poliosis can be found, several genetic disorders involve poliosis such as Marfan’s syndrome, Vogt-Koyanagi-Harada (VKH) syndrome, and Waardenburg’s syndrome. These syndromes involve other physical symptoms and mental retardation to varying degrees.
Piebaldism
True human piebaldism is a rare disorder. Piebaldism involves distinct patches of skin and hair that contain no pigment. Melanocytes are completely lacking in these hypopigmented regions. Surrounding skin and hair show normal pigmentation. Piebaldism often presents as a white forelock of scalp hair, but patches of depigmented hair or skin can occur anywhere on the body and there may be more than one affected area. Piebaldism can look much like poliosis in its basic presentation. The difference is that piebaldism is a genetic abnormality that affects a single, specific gene.
In contrast to autosomal recessive albinism, classic piebaldism is a genetic disease with autosomal dominant inheritance. It involves mutations of a gene called the kit proto-oncogene that encode a melanocyte pigment cell surface receptor called tyrosine kinase, The ligand that binds to this cell receptor is an embryonic stem cell growth factor. This growth factor has been given various names in the medical literature including; steel factor (SLF), stem cell factor, mast cell growth factor, and Kit ligand. There are several subtly different genetic abnormalities that can occur in the kit proto-oncogene but regardless of the particular mutation involved the result is that the tyrosine kinase cell receptor does not function properly.
When the defective tyrosine kinase receptor is bound by the embryonic growth factor, it does not correctly transfer a signal to nucleus of the cell on which it is expressed. Without this signal from the receptor, the cell nucleus does not know that it should start to transcribe particular genes in order to make cell proteins involved in proliferation and differentiation of melanocytes. This results in reduced melanocyte cell proliferation or reduces cell migration during embryologic development. The result is that the affected individual is born with patches of skin in which no melanocyte cells are present. Melanocye cells are the cells that produce pigment for skin and hair, so their absence in an area of skin means that the skin and hair there is not pigmented.
Although piebaldism usually involves symptoms strictly limited to changes in hair and skin color, there is a suggestion that the condition can also involve deafness for some people. Several case reports have identified varying degrees of deafness in association with a white forelock and/or patches of leukoderma (Reed 1967, Comings 1966, Selmanowitz 1977).
Treatments are mostly experimental in nature. For small white spots the most simple answer is to cut out the affected skin. However, with larger areas of affected skin and hair this is not practical. Some experiments have been conducted in which melanocyte pigment cells are taken from normally pigmented skin and transplanted to the unpigmented skin. This approach can be quite successful although results from patient to patient are variable.

Vitiligo induced gray hair
Gray or white hair onset can be due to the development of vitiligo. Vitiligo involves a progressive loss of pigment from the epidermis. Milky-white patches of skin appear resulting in cosmetic disfiguration that is most apparent in dark-skinned individuals. Vitiligo is a disease with autoimmune components where the melanocyte pigment producing cells are disrupted. While this commonly affects the pigment cells in the skin, if the vitiligo develops in a hair bearing area, the melanocytes in the hair follicles can also be adversely affected. The result can be patchy gray or white hair growth.
Interestingly for hair biologists, hair follicles in vitiligo patches can be resistant to loss of pigment. While the melanocyte pigment producing cells in the skin are rapidly destroyed, the melanocytes in the hair follicles can survive for some time before succumbing to the disease. It seems that the hair follicles provide some protection from the effect of vitiligo – at least for a while. This phenomenon has been exploited in some approaches to vitiligo treatment. Once the vitiligo has stabilized, it is possible to transplant pigmented skin and hair follicles to areas of vitiligo and the melanocytes in the transplant spread out into the diseased skin and repigment it. The belief is that the hair follicles provide a reservoir of melanocytes which are able to proliferate and repopulate the skin.
hair color and neurofibromatosis
Neurofibromas typically represent proliferation of the connective tissue cells of peripheral nerves and deposition of collagenous extra cellular matrix. Neurofibromas can cause a variety of symptoms from physical lumps in the skin to non visible symptoms such as deafness. Neurofibromas may occur in many locations – wherever connective tissue is present. Skin is a common location for neurofibroma development.
In a minority of cases, neurofibromas in the skin can be associated with increased, and occasionally decreased pigmentation. As a result, skin neurofibromas can sometimes be visible as skin discoloration. If the neurofibromas develop where there is lots of hair, as on the scalp, the hair color may also be noticeably different. Hair hyperpigmentation and poliosis due to neurofibromatosis have each been described.
The presence of neurofibromas can also alter the nature of hair growth in the immediate vicinity. Hair whorls have been reported occurring above a neurofibroma. Hypertrichosis in the vicinity of a neurofibroma may also be found.
The primary treatment for skin located neurofibromas is surgery to remove the cell mass. Any affected skin and hair may also be cut out if the lesion is small.

Sudden white hair onset
There are many folk tales from different parts of the world about people going white overnight, particularly after having a sudden and extreme shock. Frequently quoted examples of famous people going white or gray overnight include Sir Thomas More and Marie Antoinette. There may be some question as to the historical accuracy in the recording of these events, but people’s hair can apparently go white overnight.
However, it’s a visual trick! Going white overnight usually happens in those who have salt and pepper hair – that is a mixture of pigmented and white hair. The pigmented hair is selectively shed while the white hair survives. The hair that is perceived as suddenly whitening was already white, but the visual illusion makes it look as though the person has gone white overnight. This sudden white hair development is most likely due to alopecia areata which can sometimes selectively target pigmented hair fiber containing hair follicles. Alopecia areata onset can sometimes be induced by sudden shock.

An overview of what hair color is.

Hair color – biochemistry. An overview of what hair pigment is made from.
Hair color – how do we get all these different hair colors and shades. Hair color comes from two basic pigments so how do we get all these different hair colors.
Hair color – why is hair colored. Why we have so much variation in hair color is anyone’s guess but here are some ideas.
Hair color – environment, weathering and hair color changes. hair color can change as a result of the environment in which we live.
Hair color – abnormal increased pigmentation. Sometimes people may experience an increase in hair pigmentation due to drugs or diseases.
Hair color – chemical induced hair color changes. Some chemicals can promote an increase or decrease in hair color.
Hair color – drug induced hair color changes. Some drugs can promote an increase or decrease in hair color.
Hair color – gray hair and age. We all develop gray hair with as we get older but what is the typical presentation?
Hair color – nutrition and hair color. Some comments on how nutrition may affect hair color.
Hair color – oculocutaneous albinism and griscelli syndrome. A collective of several different genetic conditions all involve albinism – a failure to produce pigment in the hair, skin, and/or eyes.
Hair color – hermansky-pudlak and chediak-higashi syndrome albinism. More examples of the family of genetic conditions that involve albinism.
Hair color – syndrome associated premature gray hair. Early or rapid onset gray hair may be associated with a variety of disorders.
Hair color – hair color changes secondary to disease. Early or rapid onset gray hair may be a secondary symptom of several disease processes.
Hair color – poliosis. Poliosis is a general term to describe the development of white patches of hair in otherwise pigmented hair bearing regions of skin.
Hair color – piebaldism. Piebaldism is one cause of patchy white hair development.
Hair color – vitiligo induced gray hair. Vitiligo can result in patchy white hair growth in some affected individuals.
Hair color – hair color and neurofibromatosis. Another condition that can result in the growth of patches of white hair.
Hair color – sudden white hair onset. Can people’s hair really go white overnight?

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