NIH scientists identify rare, genetic disorder that causes blindness

Researchers at the National Eye Institute have identified the genetic underpinnings of a rare disorder that causes children to be born with deafness, blindness, albinism and fragile bones, according to a press release.

The newly recognized syndrome, COMMAD, affects children who inherit two mutations of a gene, one from each parent, each of whom is deaf due to another rare, genetic disorder called Waardenburg syndrome 2A.

COMMAD stands for coloboma (a condition where normal tissue in or around the eye is missing), osteopetrosis (abnormally dense bones that are prone to fracture), microphthalmia (small or abnormally formed eyes), macrocephaly (abnormal enlargement of the head), albinism (lack of melanin in the skin, hair and eyes) and deafness.

The identification of COMMAD and its genetic cause is significant, as intermarriage within the deaf community is relatively common and people who are deaf may not know that their deafness is associated with Waardenburg 2A, according to the release.

If both individuals have Waardenburg 2A, they are at risk of passing mutated versions of a critical gene to their child, according to the release.

The vast majority of Americans born deaf do not have Waardenburg syndrome 2A. A comprehensive dilated eye exam may detect eye abnormalities that suggest the need for genetic testing to rule out Waardenburg 2A, the NEI said.

A paper documenting the first recognized cases of COMMAD appears in the American Journal of Human Genetics.

Reference:

George A, et al. Am J Hum Genet. 2016;99(6):1388-1394.

Source: www.nei.nih.gov