The tyrosinase (TYR) gene is located on chromosome 11q14. This protein coding gene produces tyrosinase, an enzyme which catalyzes a total of three steps in the conversion of tyrosine to the end product, melanin. This enzyme and conversion process takes place within melanocytes, which are specialized cells for melanin production. Melanin is a large group of molecules that give skin, eyes, and hair their respective colors. It is also partially responsible for vision, as it protects the light sensitive portion of the eye, the retina, through absorbing light. OCA Type 1A is an autosomal recessive condition, meaning there is a homozygous or compound heterozygous mutation related to the TYR gene. There are many different types of<unk> , differing due to the effects of various mutations.<unk> A is the most severe type of<unk> , as it is characterized by no melanin production. Other types of<unk>  have limited melanin production. Because type IA<unk>  has no functioning copies of the gene, it is the most severe type of<unk> . The mutations on this gene lead to a complete lack of tyrosinase activity as the inactive enzyme is produced. An inactive enzyme can be caused by a missense or nonsense mutation. Due to the lack of enzymes needed to catalyze the production of melanin, patients do not have melanin protecting them from the sun, resulting in sensitive eyes, skin, and other symptoms mentioned in the signs and symptoms of OCA1A. The different forms of<unk>  and range of severity is dependent upon the level of melanin production, which depends on the level of tyrosinase activity.
Oculocutaneous albinism type I
Ocular albinism type 1
Ocular albinism
Retinoschisis
Lafora disease
Yemenite deaf-blind hypopigmentation syndrome
Danon disease
Hypohidrotic ectodermal dysplasia