Men who have an extra X chromosome have an elevated risk of developing autism, schizophrenia or bipolar disorder, according to a study published in the January issue of the Journal of Psychiatric Research1. The results provide further support for a connection between autism and the X chromosome. Several X chromosome genes — including the genes that lead to fragile X syndrome and Rett syndrome, along with NLGN3 and NLGN4 — are linked to autism. Mutations in X chromosome genes may explain the higher prevalence of autism in males than in females.
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