Evidence supporting WNT2 as an autism susceptibility gene

• Published in: American journal of medical genetics Vol. 105; no. 5; pp. 406 - 413
• Main Authors: Wassink, Thomas H., Piven, Joseph, Vieland, Veronica J., Huang, Jian, Swiderski, Ruth E., Pietila, Jennifer, Braun, Terry, Beck, Gretel, Folstein, Susan E., Haines, Jonathon L., Sheffield, Val C.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 08-07-2001; Wiley-Liss
• Subjects: Amino Acid Sequence; Amino Acid Substitution; autism; Autistic Disorder - genetics; Autistic Disorder - pathology; Base Sequence; Biological and medical sciences; Blotting, Northern; Brain - metabolism; candidate gene; Child clinical studies; chromosome 7q; Developmental disorders; DNA - chemistry; DNA - genetics; DNA Mutational Analysis; Family Health; Female; Gene Expression; Humans; Infantile autism; Linkage Disequilibrium; Male; Medical genetics; Medical sciences; Mental and behavioral disorders; Pedigree; Point Mutation; Polymorphism, Single Nucleotide; Polymorphism, Single-Stranded Conformational; Proto-Oncogene Proteins - genetics; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; RNA, Messenger - genetics; Sequence Homology, Amino Acid; Wnt2 Protein; Human; Linkage; Long arm; Family study; Pathogenesis; Developmental disorder; Chromosome C7; Linkage equilibrium; Genetic determinism; Autism; Gene; Psychopathology; Mutation
• ISSN: 0148-7299; 1096-8628
• DOI: 10.1002/ajmg.1401

We examined WNT2 as a candidate disease gene for autism for the following reasons. First, the WNT family of genes influences the development of numerous organs and systems, including the central nervous system. Second, WNT2 is located in the region of chromosome 7q31–33 linked to autism and is adjacent to a chromosomal breakpoint in an individual with autism. Third, a mouse knockout of Dvl1, a member of a gene family essential for the function of the WNT pathway, exhibits a behavioral phenotype characterized primarily by diminished social interaction. We screened the WNT2 coding sequence for mutations in a large number of autistic probands and found two families containing nonconservative coding sequence variants that segregated with autism in those families. We also identified linkage disequilibrium (LD) between a WNT2 3′UTR SNP and our sample of autism‐affected sibling pair (ASP) families and trios. The LD arose almost exclusively from a subgroup of our ASP families defined by the presence of severe language abnormalities and was also found to be associated with the evidence for linkage to 7q from our previously published genomewide linkage screen. Furthermore, expression analysis demonstrated WNT2 expression in the human thalamus. Based on these findings, we hypothesize that rare mutations occur in the WNT2 gene that significantly increase susceptibility to autism even when present in single copies, while a more common WNT2 allele (or alleles) not yet identified may exist that contributes to the disorder to a lesser degree. © 2001 Wiley‐Liss, Inc.