Question

In case of Albinism, answer the following:

A. Define albinism in detail

B. Name the categories of it

C. Draw or use figures ( from any website ) to compare the metabolic

pathway between normal and patient with Albinism

Answer 1

Solution:

A. Albinism is the depigmentation of eyes, skin and hairs.This is due to the non-production of the pigment melanin. The depigmented individuals are known as albinos. They are charecterised by white skin, white and silky hairs and blue or pink eyes. Albinos are highly sensitive to bright light. It is difficult for them to open their eyes to bright light. Bright sunlight may even burn their skin.

Melanin is synthesised in the body from dihydroxyphenylalanine (DOPA), which in turn, is formed from tyrosine. Tyrosine and DOPA are the intermediate products in the metabolic pathway of phenylalanine.The conversion of tyrosine to DOPA is mediated by the enzyme tyrosinase, and the synthesis of melanin from DOPA is mediated by DOPA oxidase. The production of each of these enzymes is governed by a dominant autosomal gene. The homozygous condition of the recessive mutant allele results in the non-production of the enzyme. This causes a metabolic block and the non-production of melanin, resulting in albinism.

B. There are two categories of several types of albinism.

1.Ocular Albinism (OA):

OA is a very rare type of albinisim,which only affects the eyes.

2.Oculocutaneous Albinism ( OCA):

OCA affects the eyes, hair and skin.

3. Metablolic pathway of a normal person and a patient with albinism is shown in the below image: