Science & Society

Children with Williams syndrome — a rare genetic disorder that leads to mental retardation and overt friendliness — hold stereotypes based on gender, but not race, according to a report published in Current Biology. Because those with Williams syndrome don’t have social fear, the study suggests racial stereotypes are based partly on fear.

Some brain areas involved in speech are larger and some smaller in children with autism compared with healthy controls, according to a series of imaging studies conducted by a Boston research group.

Two independent teams have identified the genetic culprits of three rare, inherited diseases by sequencing the genomes of several members of the same family. As the cost of whole-genome sequencing plummets, this family-based approach will reveal candidate genes not just for rare diseases but for common, complex disorders such as autism, experts say.

Attention deficit hyperactivity disorder (ADHD) and autism may have more in common than childhood onset and a few similar symptoms. New research suggests the conditions share genetic roots.

Random changes in gene expression can cause genetically identical embryos to develop different traits, according to a study of worms published in Nature. The findings suggest that haphazard movements of molecules could partly explain why autism-associated mutations don’t always cause the same symptoms.