Constitutional downregulation of SEMA5A expression in autism.
There is strong evidence for the importance of genetic factors in idiopathic autism. The results from independent twin and family studies suggest that the disorder is caused by the action of several genes, possibly acting epistatically. We have used cDNA microarray technology for the identification of constitutional changes in the gene expression profile associated with idiopathic autism. Samples were obtained and analyzed from 6 affected subjects belonging to multiplex autism families and from 6 healthy controls. We assessed the expression levels for approximately 7,700 genes by cDNA microarrays using mRNA derived from Epstein-Barr virus-transformed B lymphocytes. The microarray data were analyzed in order to identify up- or downregulation of specific genes. A common pattern with nine downregulated genes was identified among samples derived from individuals with autism when compared to controls. Four of these nine genes encode proteins involved in biological processes associated with brain function or the immune system, and are consequently considered as candidates for genes associated with autism. Quantitative real-time PCR confirms the downregulation of the gene encoding SEMA5A, a protein involved in axonal guidance. Epstein-Barr virus should be considered as a possible source for altered expression, but our consistent results make us suggest SEMA5A as a candidate gene in the etiology of idiopathic autism.
Melin
M
M
Department of Genetics and Pathology, The Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.
Carlsson
B
B
Anckarsater
H
H
Rastam
M
M
Betancur
C
C
Isaksson
A
A
Gillberg
C
C
Dahl
N
N
D000293:Adolescent; D001321:Autistic Disorder / Q000235:genetics* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D015536:Down-Regulation / Q000502:physiology*; D005260:Female; D015870:Gene Expression / Q000502:physiology; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D039961:Semaphorins
D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C491228:SEMA5A protein, human; D039961:Semaphorins