title: Fine mapping of the locus for Shwachman-Diamond syndrome at 7q11, identification of shared disease haplotypes, and exclusion of TPST1 as a candidate gene.
abstract: Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterised by exocrine pancreatic dysfunction, haematological and skeletal abnormalities. We have previously defined the SDS locus as a 2.7 cM interval spanning the centromere of chromosome 7. To facilitate additional analysis of this complex and poorly characterised region, a framework of ordered genetic markers at 7p11-q11, including six newly identified, has been constructed using somatic cell, radiation hybrid and STS-content mapping. We have identified shared disease haplotypes, that recur in unrelated families of common ethnic origin, and extend across the SDS locus. Detection of ancestral and intrafamilial recombination events in patients refined the SDS locus to a 1.9 cM interval at 7q11, which contains the tyrosylprotein sulfotransferase 1 (TPST1) gene. Patients with SDS were screened for mutations in TPST1 by sequencing of exons and intron-exon junctions. Two single nucleotide polymorphisms, but no disease-causing mutations, were identified. In addition, Southern blot analysis yielded no evidence of large-scale mutations, and RT-PCR analysis failed to detect alterations in expression. These results exclude TPST1 as the causative gene for SDS. The established map of the refined SDS locus will assist in the identification and characterisation of other candidate genes for SDS.
authors.affiliation: Program in Genetics and Genomic Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Maja
authors.initials: M
authors.lastname: Popovic
authors.forename: Sharan
authors.initials: S
authors.lastname: Goobie
authors.forename: Jodi
authors.initials: J
authors.lastname: Morrison
authors.forename: Lynda
authors.initials: L
authors.lastname: Ellis
authors.forename: Nadia
authors.initials: N
authors.lastname: Ehtesham
authors.forename: Nicole
authors.initials: N
authors.lastname: Richards
authors.forename: Graeme
authors.initials: G
authors.lastname: Boocock
authors.forename: Peter R
authors.initials: PR
authors.lastname: Durie
authors.forename: Johanna M
authors.initials: JM
authors.lastname: Rommens
mesh_terms: D002897:Chromosomes, Human, Pair 7 / Q000235:genetics*; D004252:DNA Mutational Analysis; D010188:Exocrine Pancreatic Insufficiency / Q000235:genetics*; D005260:Female; D006239:Haplotypes; D006402:Hematologic Diseases / Q000235:genetics*; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D009139:Musculoskeletal Abnormalities / Q000235:genetics*; D010375:Pedigree; D020161:Physical Chromosome Mapping; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015238:Sulfotransferases / Q000235:genetics* / Q000378:metabolism; D013577:Syndrome
chemical_list: D015238:Sulfotransferases; C039079:protein-tyrosine sulfotransferase