Disruption of the ASTN2/TRIM32 locus at 9q33.1 is a risk factor in males for autism spectrum disorders, ADHD and other neurodevelopmental phenotypes

Hum Mol Genet. 2014 May 15;23(10):2752-68. doi: 10.1093/hmg/ddt669. Epub 2013 Dec 30.

Abstract

Rare copy number variants (CNVs) disrupting ASTN2 or both ASTN2 and TRIM32 have been reported at 9q33.1 by genome-wide studies in a few individuals with neurodevelopmental disorders (NDDs). The vertebrate-specific astrotactins, ASTN2 and its paralog ASTN1, have key roles in glial-guided neuronal migration during brain development. To determine the prevalence of astrotactin mutations and delineate their associated phenotypic spectrum, we screened ASTN2/TRIM32 and ASTN1 (1q25.2) for exonic CNVs in clinical microarray data from 89 985 individuals across 10 sites, including 64 114 NDD subjects. In this clinical dataset, we identified 46 deletions and 12 duplications affecting ASTN2. Deletions of ASTN1 were much rarer. Deletions near the 3' terminus of ASTN2, which would disrupt all transcript isoforms (a subset of these deletions also included TRIM32), were significantly enriched in the NDD subjects (P = 0.002) compared with 44 085 population-based controls. Frequent phenotypes observed in individuals with such deletions include autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), speech delay, anxiety and obsessive compulsive disorder (OCD). The 3'-terminal ASTN2 deletions were significantly enriched compared with controls in males with NDDs, but not in females. Upon quantifying ASTN2 human brain RNA, we observed shorter isoforms expressed from an alternative transcription start site of recent evolutionary origin near the 3' end. Spatiotemporal expression profiling in the human brain revealed consistently high ASTN1 expression while ASTN2 expression peaked in the early embryonic neocortex and postnatal cerebellar cortex. Our findings shed new light on the role of the astrotactins in psychopathology and their interplay in human neurodevelopment.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Attention Deficit Disorder with Hyperactivity / genetics*
  • Case-Control Studies
  • Child
  • Child Development Disorders, Pervasive / genetics*
  • Child, Preschool
  • Chromosomes, Human, Pair 9
  • DNA Copy Number Variations
  • Exons
  • Female
  • Gene Expression
  • Genetic Association Studies
  • Genetic Predisposition to Disease
  • Glycoproteins / genetics*
  • Glycoproteins / metabolism
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism
  • Organ Specificity
  • Phenotype
  • Polymorphism, Single Nucleotide
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / metabolism
  • Risk Factors
  • Sequence Deletion
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Transcription Initiation Site
  • Tripartite Motif Proteins
  • Ubiquitin-Protein Ligases
  • Young Adult

Substances

  • ASTN1 protein, human
  • ASTN2 protein, human
  • Glycoproteins
  • Nerve Tissue Proteins
  • Protein Isoforms
  • Receptors, Cell Surface
  • Transcription Factors
  • Tripartite Motif Proteins
  • TRIM32 protein, human
  • Ubiquitin-Protein Ligases