1. Oculocutaneous Albinism (OCA): This type of albinism affects hair (white hair), eyes (iris of the eye looks pink), and skin (pale in colour). There are four different types of oculocutaneous albinism (OCA1 to OCA4). It is caused by genetic mutations (defects) that cause the lack of the pigment melanin. This type of albinism occurs in one out of twenty thousand people. OCA4 (oculocutaneous albinism type 4) is caused by the genetic defect in the SLC45A2 protein which assists the tyrosinase enzyme (tyrosinase enzyme aids the body to convert the amino acid tyrosine into pigment) to function. Those with OCA4 make very little amounts of melanin.
2. Ocular Albinism (OA1): This type of albinism is more rare and occurs in one out of fifty thousand people. It primarily affects the eyes (ocular tissues). This type of albinism is caused by the genetic defect in GPR143 gene (this gene is a type of "signal" that is crucial to the pigmentation in the eye. The retina has no colour if a person has ocular albinism. There is only slight colouring in the hair and skin. The gene that is affected is on the X chromosome. Females have two X chromosomes and males have one (and a Y chromosome). OA1 is far more common in males than females since males only require one defective copy of the gene.
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| Ocular Albinism |
