Deletion Involving the 7q31-32 Band at the CADPS2 Gene Locus in a Patient with Autism Spectrum Disorder and Recurrent Psychotic Syndrome Triggered by Stress

Received May 8, 2017; Accepted Sep 13, 2017

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1. Introduction

Autism is a neurodevelopmental disorder marked by impairments in social functioning, language, communication, and behavior. Epidemiological studies show that the prevalence of autistic spectrum disorders (ASDs) is 3–6/10,000, with a ratio of 3 men to each woman. The concordance rates in monozygotic and dizygotic twins are about 90% and 10%, respectively, suggesting a strong genetic component [1]. Cytogenetic studies have shown alterations in chromosomes 2, 3, 4, 5, 7, 8, 11, 13, 15, 16, 17, 19, 22, and X, including deletions, duplications, translocations, and inversions [2]. Several mutations have already been linked with autism and include, for example, the CYFIP1M, GABRB3, and UBE3A genes [3]. Mutations in the CADPS2 gene have also been associated with the disorder [4].

The activating protein family, which depends on calcium for secretion, consists of two members: CADPS and CADPS2 (Ca²⁺-dependent activator protein for secretion 2) [5–7]. Studies indicate that CADPS is involved in vesicle release during exocytosis [5, 8–10]. CADPS2 is immunohistochemically related to the release of brain-derived neurotrophic factor in various regions of the brain in mice. CADPS2 mRNA is found in several mice tissues, predominantly in the brain [11]. CADPS2 in humans is located on chromosome 7q31-32 at the AUTS1 locus [12]. Recent genome-wide association studies show some microdeletions on 7q31-32, including the locus of CAPS2, in autistic patients [12–14]. The presence of a de novo copy number variation due to microdeletions in the region containing CADPS2 has also been reported in some autistic...