Identical twins can be genetically different, which could explain why they do not always share disorders such as schizophrenia or autism, according to a study published in March in PLoS One.
From parental age to infection during pregnancy, environmental elements can influence autism risk.
Children with autism and those who have fathers older than 31 both have lower-than-normal levels of proteins that regulate other genes, according to a study published in February in PLoS One.
Cultural stigma, lack of awareness about mental health and poor medical infrastructure have led to inaccurate diagnoses and artificially low autism prevalence in many countries around the world, epidemiologists say.
Genetic syndromes associated with autism are increasingly being diagnosed in utero because of techniques that can identify subtle mutations in the genome. But the technology is ahead of the ethical debate on whether and how to inform parents about mutations with unknown effects.
A gene that regulates the conversion of testosterone to estrogen in the brain could help explain why males are more susceptible to autism than are females, according to a study published in PLoS One in February.