Children Infants with Albinism

Children & Infants with Albinism
http://www.visionaustralia.org.au/info.aspx?page=672

With thanks to Dr James Elder, Ophthalmologist.

Albinism
Albinism is an inherited condition. It affects the eyes and skin of some individuals, and only the eyes of others. It results from the body's inability to produce normal amounts of a pigment called melanin.

Children with oculocutaneous albinism, where both the skin and eyes are affected, can present with varying degrees of pigment. Some children have white hair, little or no pigment in the skin, pale coloured eyes and significant vision impairment. Others with more pigment may have red-brown hair, some skin colour, blue or brown eyes and less severe vision impairment.

Children with ocular albinism have vision impairment but the hair and skin are normal or near-normal in colour.


Oculocutaneous Albinism
This type of albinism usually occurs as a result of autosomal recessive inheritance, where both parents carry one gene for albinism. Recessive inheritance is the result of receiving one defective gene from each parent.

All of our genes come in pairs and if one gene is normal and the other is defective, in a recessive disorder there will be no abnormality. In oculocutaneous albinism the parents, or carriers, usually have normal pigmentation and vision, but when a defective gene is inherited from each parent, the child will have a pair of defective genes and will develop the disease.

In recessive inheritance, there is a one-in-four chance with each pregnancy that the child will have albinism. Both boys and girls can be affected.


Ocular Albinism
This type of albinism can also be recessively inherited, with both boys and girls being affected and a one-in-four chance with each pregnancy.

Ocular albinism can also be X-linked, where the gene for albinism is passed on with the X-chromosome. X-linked diseases result from the difference in the chromosomes of men and women.

Men have an X and Y chromosome and women have two X chromosomes. A disease which is caused by a defective gene on the X chromosome is much more likely to affect men as the Y chromosome will not have a matching normal gene.

Women are carriers of X-linked diseases as, almost always, there will be a normal matching gene on the second X-chromosome. In this form of inheritance, there is a one-in-two chance that sons will have albinism.

Following the birth of a child with albinism, genetic counselling can provide parents with information regarding the risk of future children having albinism