TYR gene

TYR gene is a gene in humans that encodes the enzyme tyrosinase. This enzyme is involved in the initial steps of melanin synthesis. Mutations in this gene are associated with oculocutaneous albinism type 1 (OCA1), a disorder characterized by a lack of pigment in the skin, hair, and eyes.

Function

The TYR gene provides instructions for making an enzyme called tyrosinase. This enzyme is located in melanocytes, which are specialized cells that produce a pigment called melanin. Melanin gives color (pigmentation) to the skin, hair, and eyes and protects the body from the harmful effects of ultraviolet (UV) radiation.

Tyrosinase catalyzes the first two steps in melanin production. It converts a protein building block (amino acid) called tyrosine to a molecule called dopaquinone. Other enzymes then convert dopaquinone to melanin.

Clinical significance

Mutations in the TYR gene disrupt the normal function of tyrosinase, preventing these cells from producing melanin effectively. Without melanin, the skin, hair, and eyes have little or no color, and the eyes may not develop normally.

Oculocutaneous albinism type 1 is characterized by white hair, very pale skin, and light-colored irises. People with this condition also have vision problems such as nystagmus and strabismus. Some mutations in the TYR gene result in a variant form of oculocutaneous albinism called "temperature-sensitive OCA1." People with this form of the disorder have white hair and skin at birth, but develop some pigmentation in these areas over time.

See also

• Oculocutaneous albinism
• Melanin
• Melanocyte
• Tyrosinase

External links

• TYR gene on the US National Library of Medicine website

TYR gene Resources
Latest articles Most recent articles Ongoing trials	Wikipedia