CNTNAP2 Gene And The Unravelling Of Autism Spectrum Disorders

If anyone doubted that we are living in the era of the Autism Knowledge Revolution they should doubt no longer. The January 10 2008 edition of the American Journal of Human Genetics includes reports of three studies which separately validate the March 2006 study led by Dr. Dietrich A. Stephan, that identified a gene called CNTNAP2 which, when mutated, suggested a predisposition to autism. In Unravelling Autism Dr. Stephan comments on the three studies and states:

In this issue of AJHG, Alarcón et al.,¹ Arking et al.,² and Bakkaloglu et al.³ identify a series of functional variants in the CNTNAP2 gene that unequivocally implicate this gene as causing Type 1 autism in the general population. ...... The modern technologies and strategies derived from the Human Genome Project, coupled with the elegant sample banking, phenotyping, and data dissemination resources of groups like AGRE, are resulting, finally, in the unraveling of Autism Spectrum Disorder.

Dr. Stephan offers characteristics of Type 1 autism which many parents will recognize in their autistic children:

The three studies herein^{1, 2, 3} have moderate sample overlap and use different strategies to narrow the phenotype of the ASD cohorts to relative homogeneity before performing genotyping/resequencing across the CNTNAP2 gene locus. Nevertheless, 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 ASD. This genetic subtype can be clinically characterized by ADOS/ADI-R-defined autism with language deficits and potential gender bias and parent-of-origin effects. Type 1 autism may also be associated with seizures.

The gender bias referred to by Dr. Stephan is the male gender bias associated with autism which sees from 3 to 1 to 4 to 1 male to female ratios amongst persons with autism. On the practical side Dr. Stephan indicates that the CNTNAP2 information might be of assistance in early detection and intervention in the 12 to 24 month period.

autism