• New DNA test helps ID rare diseases linked to congenital cataracts

    Written By: Shirley Dang
    Aug. 22, 2014

    Most people know cataracts as a condition that can cause blindness in the elderly. However, between 20,000 and 40,000 children worldwide are born with congenital cataracts each year. A significant portion of these cases are linked to 100 or more rare inheritable diseases that can be difficult to diagnose and treat because symptoms in babies can be subtle.

    To remedy this problem, researchers at the University of Manchester developed a new advanced DNA test that can quickly and more accurately diagnose rare diseases in which congenital cataracts often appear as a symptom. Being able to identify the underlying medical conditions enables doctors to give proper treatment and genetic counseling for affected families much sooner than previously possible.

    Using advanced gene sequencing technology, researchers can check for mutations in the 115 genes known to be associated with congenital cataract in a single test. In 75 percent of cases, they are able to identify the disease based on the mutations, according to a study published in Ophthalmology, the official journal of the American Academy of Ophthalmology.

    In the course of their work, done in collaboration with Manchester Royal Eye Hospital, researchers also found previously undescribed mutations linked to the development of cataracts.

    “There is hope that our work may one day provide more insight into the development and treatment of age-related cataracts, a leading cause of blindness worldwide,” said Rachel Gillespie, MSc, lead author of the study, who designed and developed the test at the University of Manchester’s Centre for Genomic Medicine.

    Infants and children who have congenital cataracts can be tested as well as prospective parents with a history of the condition who wish to evaluate the risk to their child. While only available in the U.K. at St. Mary’s Hospital in Manchester, the congenital cataract DNA test can be requested by registered medical facilities through international referral. Results generally take about two months.