High-density SNP association study of the 17q21 chromosomal region linked to autism identifies CACNA1G as a novel candidate gene

Source: 
Molecular Psychiatry, Strom, Stone, Bosch, Merriman, Cantor, Geschwind, and Nelson
Year Published: 
2009

(From a UCLA press release) UCLA scientists have discovered a variant of a gene called CACNA1G that may increase a child's risk of developing autism, particularly in boys. "We found that a common form of the gene occurs more frequently in the DNA of families that have two or more sons affected by autism, but no affected daughters," explained Dr. Stanley Nelson, professor of human genetics at the David Geffen School of Medicine at UCLA. The researchers traced the genetic markers to CACNA1G, which helps move calcium between the cells. They discovered that the gene has a common variant that appears in the DNA of nearly 40 percent of the population. "This alternate form of CACNA1G consistently increased the correlation to autism spectrum disorder, suggesting that inheriting the gene may heighten a child's risk of developing autism," observed Nelson. How the gene contributes to higher autism risk remains unclear, but Nelson emphasized that it cannot be considered a risk factor on its own. "This variant is a single piece of the puzzle," he said. "We need a larger sample size to identify all of the genes involved in autism and to solve the whole puzzle of this disease." The UCLA team's next step will be to sequence the gene in people who possess the altered variant in order to identify the exact change that increases autism risk. These subtle variations offer potential markers for the real mutation causing greater susceptibility to the disease.