Female with autistic disorder and monosomy X (Turner syndrome): Parent‐of‐origin effect of the X chromosome

Abstract

We have ascertained and examined a patient with autistic disorder (AD) and monosomy X (Turner syndrome). The patient met Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV)/International Classification of Diseases (ICD‐10) criteria for AD verified by the Autism Diagnostic Interview—Revised. The patient exhibited both social and verbal deficits and manifested the classical physical features associated with monosomy X. Skuse et al. [1997: Nature 387:705–708] reported three such cases of AD and monosomy X in their study of Turner syndrome and social cognition. They observed that monosomy X females with a maternally inherited X chromosome had reduced social cognition when compared with monosomy X females with a paternally inherited X chromosome. All three cases of AD and monosomy X were maternally inherited. Based on their data, they suggested that there was a gene for social cognition on the X chromosome that is imprinted and not expressed when the X chromosome is of maternal origin. Thus, we conducted parent‐of‐origin studies in our AD/monosomy X patient by genotyping X chromosome markers in the patient and her family. We found that the patient's X chromosome was of maternal origin. These findings represent the fourth documented case of maternal inheritance of AD and monosomy X and provide further support for the hypothesis that parent‐of‐origin of the X chromosome influences social cognition. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:312–316, 2000. © 2000 Wiley‐Liss, Inc