December 2012

Digging into the Genes of Rare Diseases

Thu, 13 December 12 09:00

Ireland has a relatively high level of rare diseases, and sometimes the genetic variations that underlie them are not found anywhere else in the world. But by analysing genes from Irish families with rare diseases, a HRB-funded study has been identifying new genes responsible for rare disorders, and developing easier ways to diagnose conditions, screen for carriers and help genetic counselling.

“If you want to have a direct impact on health in the Irish population, you need to be doing the research on the Irish families,” says Dr Jillian Casey, a post-doc at the National Children’s Research Centre. Working within families that have a history of a rare condition, the researchers have been looking for regions of DNA that are common to all of the affected individuals but that are not shared by their healthy relatives.

Their search has led them to identify a key eye development gene associated with a micro-anophthalmia where eyes fail to form normally. “We showed for the first time that changes in this gene can cause an isolated eye disorder,” says Dr Casey.

The team, co-led by Dr Sean Ennis, UCD, and Dr Sally Ann Lynch, National Centre for Medical Genetics, also identified another gene linked with familial glucocorticoid deficiency, which can result in poor growth and a high susceptibility to viral infections.

The findings have led to the development of genetic tests for use in the clinical setting to help with earlier diagnosis and to identify carriers in affected families. Further research is also helping to develop a single screening test to diagnose an array of rare diseases present in the Irish population.

This article is reproduced from the Health Research Board (HRB) Picture of Health 2012 publication.

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