33 genes linked to autism 'identified'
23 April, 2012
WASHINGTON: Scientists claim to have identified 33 genes linked to autism and related disorders, a finding which may pave the way for better treatments for the medical condition.
"By sequencing the genomes of a group of children with neuro-developmental abnormalities, including autism, who were also known to have abnormal chromosomes, we identified the precise points where the DNA strands are disrupted and segments exchanged within or between chromosomes. "As a result, we were able to discover a series of genes that have a strong individual impact on these disorders," says James Gusella at Massachusetts General Hospital Center for Human Genetic Research, who led an international team.
He added, "We also found that many of these genes play a role in diverse clinical situations, from severe intellectual disability to adult-onset schizophrenia, leading to conclusion these genes are very sensitive to even subtle perturbations."
To get a clearer view of the potential impact of BCAs on autism, the team took advantage of a new approach which allows the sequencing of an individual's entire genome in a way that detects the breakpoints of BCAs.
The whole procedure can be accomplished in less than two weeks rather than the many months previously required.
Screening the genomes of 38 individuals diagnosed with autism or other neuro-developmental disorders found chromosomal breakpoints and rearrangements in non-protein-coding regions that disrupted 33 genes, only 11 of which previously had been suspected in these disorders.
"The theory that schizophrenia is a neuro-developmental disorder has long been hypothesized, but we are just now beginning to uncover specific portions of the genetic underpinnings that may support that theory.
"We also found that different gene variations -- deletion, duplication or inactivation -- can result in very similar effects, while two similar changes at the same site might have very different neuro-developmental manifestations.
"We suspected that the genetic causes of autism and other neuro-developmental abnormalities are complex and likely to involve many genes, and our data support this," the scientists said in the Cell' journal.