Working with Dr Hui Sun and Dr Riki Kawaguchi of the University of California, the research team went on to show that the genetic mutation identified in these patients significantly impairs the ability of STRA6 to transport vitamin A into the cells. From this we pinpointed STRA6, a gene responsible for transporting vitamin A into cells." "Using advanced gene sequencing technologies, we firstly scanned for regions of DNA shared by all patients before analysing a single common region for the disease gene. "Our scientific study involved nine individuals from across several generations of an Irish ethnic minority family of nomadic descent who suffer with one or more of the three eye defects to varying degrees of severity," said Dr Sean Ennis from the UCD School of Medicine and Medical Science, University College Dublin, and the National Centre for Medical Genetics, who led the research. They can also be associated with other birth defects such as malformations of the heart, lungs and diaphragm.Īccording to the Micro & Anophthalmic Children's Society UK, Anophthalmia occurs in around 1 in 100,000 births, and Microphthalmia and Coloboma occur in around 1 in 10,000 births. There is no clinical treatment for anophthalmia (the absence of one or both eyes), and children born with the condition must have prosthetic eyes fitted to help their face and skull to develop naturally.Īnophthalmia (absence of one or both eyes), and its sister conditions microphthalmia (small eye) and coloboma (malformed eye), arise during the development of the baby in the womb.Īlthough individually rare, these three major structural eye defects account for 11% of all childhood visual impairments. If identified, the couples can receive advice and counselling about the implications of carrying the gene alteration for their present and future children. This new discovery means that scientists can now develop a genetic test for couples who may be carrying the altered gene and planning to have children. According to the findings published in the current issue (December 2011) of Human Mutation, a child's eyes will not develop fully in the womb if the child has alterations in both copies of its STRA6 gene which is responsible for transporting vitamin A into the cells.