Adding up autism risks The causes of autism and autism spectrum
disorder (ASD) are complex, and contain elements of both nature
(genes) and the environment. New research published in BioMed
Central's open access journal Molecular Autism shows that common
genetic polymorphisms (genetic variation) can add up to an
increased risk of ASD. The contribution of inheritance and
genetic mutation versus environmental factors to the risk of ASD
is hotly debated. Most twin studies show the contribution
heavily tilted toward inheritance, but the exact amount of
involvement of genes in ASD risk is less apparent. This is
because, while the impact of rare genetic variations on ASD risk
is becoming clear, the role of more common variations, so called
single nucleotide polymorphisms (SNP), remains unresolved. In a
vast project involving researchers across the USA, genetic data
from families in the Simons Simplex Collection (where one child,
but neither parent or any brothers or sisters, have ASD) and the
Autism Genome Project