Bilateral anophthalmia is extremely rare, affecting around one in every 100 000 births, and occurs when the fetus does not develop eyes during the first month of pregnancy. Babies with this condition are born with empty eye sockets, and often have to be fitted with prosthetic eyes to allow their faces to develop normally.

Researchers from the Medical Research Council's Human Genetics Unit in Edinburgh say that at least some cases of bilateral anophthalmia may have their roots in a mutation of a gene called SOX2. They tested the SOX2 gene in children born with the condition and found mutations in many of them. The research, published in Nature Genetics in April 2003, shows that SOX2 plays a critical role in eye development and could help doctors understand bilateral anophthalmia more fully.

The research also indicate that the genetic mistakes in SOX2 leading to bilateral anophthalmia are not passed down from the parents, but seem to rise spontaneously in either the egg or sperm. This finding should help reassure parents who fear that the blindness could have been their fault.

The Edinburgh researchers believe that other genes that interact directly with SOX2 may be mutated in children affected with similar and more common eye conditions, such as retinal and macular degeneration, cataracts and glaucoma. Further exploration of these interactions could help patients with these degenerative eye conditions. The aim is to identify the specific genetic causes of these various malformations, then develop methods to prevent them occurring in the first place.

Further reading

Fantes J, et al. Mutations in SOX2 cause anophthalmia. Nature Genetics 2003 33(4): 461-3. Abstract