A large number of people with sporadic cases of schizophrenia do not necessarily have a family history of the disease. In fact, a new study published in Nature Genetics establishes that they are caused by rare "de novo", protein-altering mutations-genetic errors that are present in patients but not in their parents.

"Here we examined the possibility that rare de novo protein-altering mutations contribute to the genetic component of schizophrenia by sequencing the exomes of 53 sporadic cases, 22 unaffected controls and their parents," said the authors of the study led by Maria Karayiorgou, MD, and Joseph A. Gogos, MD, PhD.

The study found 40 mutations, all from different genes and most of them protein-altering.

The study paves way to finding more mutations that contribute to the genetics of schizophrenia.

So far, experts agreed that schizophrenia develops as a result of interplay between biological predisposition (for example, inheriting certain genes) and the kind of environment a person is exposed to.

Our analyses suggest a major role for de novo mutations in schizophrenia as well as a large mutational target, which together provide a plausible explanation for the high global incidence and persistence of the disease, said the report.