Authors: Stavros Bashiardes Rose Veile Missy Allen Carol A Wise Mathew Dobbs Jose A Morcuende Lazlos Szappanos John A Herring Anne M Bowcock Michael Lovett
Publish Date: 2004/04/16
Volume: 115, Issue: 1, Pages: 81-89
Abstract
Idiopathic scoliosis IS affects approximately 2–3 of the population and has a heritable component The genetics of this disorder are complex Here we describe a family in which a pericentric inversion of chromosome 8 cosegregates with IS We have used fluorescence in situ hybridization to identify cloned DNAs that span the breakpoints on the two arms of the chromosome We have identified a bacterial artificial chromosome BAC of 150 kb that crosses the qarm breakpoint and a BAC of 120 kb that crosses the parm breakpoint The complete genomic DNA sequence of these BACs has been analyzed to identify candidate genes and to localize further the precise breakpoints This has revealed that the parm break does not interrupt any known gene and occurs in a region of highly repetitive sequence elements On the qarm the break occurs between exons 10 and 11 of the γ1 syntrophin SNTG1 gene Syntrophins are a group of cytoplasmic peripheral membrane proteins that associate directly with dystrophin the Duchenne muscular dystrophy gene γ1syntrophin has been shown to be a neuronal cellspecific protein Mutational analysis of SNTG1 exons in 152 sporadic IS patients has revealed a 6bp deletion in exon 10 of SNTG1 in one patient and a 2bp insertion/deletion mutation occurring in a polypyrimidine tract of intronic sequence 20 bases upstream of the SNTG1 exon 5 splice site in two patients These changes were not seen in a screen of 480 control chromosomes Genomic DNAs from seven affected individuals within the family of a patient carrying the 6bp deletion were typed to determine whether the alteration cosegregated with IS The deletion was only observed in five out of these seven individuals Thus although genetic heterogeneity or multiple alleles cannot be ruled out the 6bp deletion does not consistently cosegregate with the disease in this family
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