Massive Genetics Study Reveals Autism-Linked Variants

By merging genetic data from two large clinical repositories, from a total of more than 30,000 children, researchers have identified 18 copy number variants (CNVs) — DNA deletions or duplications — that play a role in autism. The findings appeared 9 October in Molecular Psychiatry.Some of the variants did not meet statistical significance in previous studies based on three large databases of children with autism. These include deletions in chromosomal regions 16p12.1 and 17q12, and duplications in 15q13.2-q13.3 and a small segment of 16p11.2 (distinct from the more famous autism-linked segment within the 16p11.2 region).The study also showed that one variant, a duplication in 15q11-13, is more common than previously thought.The study underscores the importance of sharing data, notes lead investigator David Ledbetter, executive vice president and chief scientific officer at Geisinger Health System in Danville, Pennsylvania.In 2007, Ledbetter co-founded the International Standards for Cytogenomic Arrays (ISCA) Consortium, a group of dozens of commercial and academic laboratories that are pooling genetic and medical data in a publicly available database.Many CNVs and other rare variants are not fully penetrant — that is, they seem to contribute to disease only in some individuals. The more people in a database who carry a particular variant, the better researchers can assess the variant’s medical significance.“We continue to work hard to convince big academic and commercial labs to donate their data,” Ledbetter says. “We’re quite confident there are more CNVs that will be shown to be pathogenic if we had even larger datasets.”On 6 November, the American College of Medical Genetics and Genomics, a prominent professional organization, released a position statement urging all genetics labs to share clinically informative data in public repositories.Read more at...SFARI, November 2012.