Characteristic symptoms of Phelan-McDermid syndrome — a disorder caused by the loss of the 22q13.3 chromosomal region — may include bipolar disorder and a sudden loss of skills during adulthood, according a study published in June in Molecular Syndromology.

A family history of schizophrenia or bipolar disorder increases the risk of autism, according to an epidemiological study published 2 July in the Archives of General Psychiatry. The results suggest that these disorders share underlying mechanisms.

The absence of a chemical alteration called methylation on some stretches of DNA makes them especially prone to mutations, according to a paper published in PLoS Genetics in May.

A biological signature in the blood could be used to aid the early diagnosis of schizophrenia, according to a study published 12 April in Molecular Psychiatry. The results suggest that various circulating immune molecules and metabolites reflect the biological changes that underlie neurological disorders.

FOXP2, a protein linked to language development that regulates the expression of some autism-associated genes, also dampens expression of DISC1, mutations in which have been linked to both schizophrenia and autism. The results were published 20 March in Human Molecular Genetics.

Genes implicated in Tourette syndrome overlap with those involved in autism, according to an analysis of rare DNA duplications and deletions in people with the syndrome, published in the March issue of Biological Psychiatry.

Lithium alleviates the symptoms of fragile X syndrome in mice in part by normalizing protein synthesis in the brain, according to a study published 29 December in Neurobiology of Disease.

Researchers have uncovered cellular abnormalities in Timothy syndrome by regenerating neurons from individuals with the rare autism-related disorder, according to a study published 27 November in Nature Medicine.

The offspring of older male mice are 16 times more likely to harbor a spontaneous copy number variation — a deletion or duplication of genetic material — than are the offspring of young males, according to a new study.

Some of the same genetic risk factors may underlie both autism and attention deficit hyperactivity disorder, according to a study published 10 August in Science Translational Medicine.