Autism Gene Glitch Traced to Moms
Glitch in CNTNAP2 Gene May Be Passed Down by Mothers
Jan. 10, 2008 -- Glitches in a gene called CNTNAP2 appear to be linked to autism, and at least one of those mutations may be handed down by mothers.
That news appears in today's online edition of The American Journal of Human Genetics.
In the journal, three teams of scientists identify CNTNAP2 as a possible autism gene.
"The three studies together identify a set of common and rare variants that provide unequivocal evidence that the CNTNAP2 gene, when disrupted, leads to a subtype of autism spectrum disorders," states an editorial published with the studies.
Here's a quick look at each study's findings.
Mom's DNA. An autism-related CNTNAP2 gene mutation is inherited from mothers, not fathers, though autism is more common in boys than girls. So say researchers, including Dan Arking, PhD, of Johns Hopkins University School of Medicine. This study doesn't mean that moms are to blame for their child's autism; Arking's team looked for genetic patterns in DNA, not autism causes.
Language link. A glitch in the CNTNAP2 gene is linked to language delay in autistic children. And the CNTNAP2 gene is active in brain areas related to language, say scientists, including Maricela Alarcon, PhD, of the UCLA Center for Autism Research and Treatment at the University of California, Los Angeles (UCLA).
Multiple mutations. More than one CNTNAP2 mutation may be linked to autism, according to experts including Betul Bakkaloglu and Matthew State, MD, PhD, of Yale University's medical school.
The CNTNAP2 gene is a "very large target for mutations," writes editorialist Dietrick Stephan, PhD, of the Translational Genomics Research Institute in Phoenix.
But that doesn't mean that CNTNAP2 is the only gene involved in autism.
The genetics of autism are complex, Stephan notes. Previous research suggests that 100 or more genes may affect autism risk.