title: A HOXA13 allele with a missense mutation in the homeobox and a dinucleotide deletion in the promoter underlies Guttmacher syndrome.
abstract: Guttmacher syndrome, a dominantly inherited combination of distal limb and genital tract abnormalities, has several features in common with hand-foot-genital syndrome (HFGS), including hypoplastic first digits and hypospadias. The presence of features not seen in HFGS, however, including postaxial polydactyly of the hands and uniphalangeal 2(nd) toes with absent nails, suggests that it represents a distinct entity. HFGS is caused by mutations in the HOXA13 gene. We have therefore re-investigated the original Guttmacher syndrome family, and have found that affected individuals are heterozygous for a novel missense mutation in the HOXA13 homeobox (c.1112A>T; homeodomain residue Q50L), which arose on an allele already carrying a novel 2-bp deletion (-78-79delGC) in the gene's highly conserved promoter region. This deletion produces no detectable abnormalities on its own, but may contribute to the phenotype in the affected individuals. The missense mutation, which alters a key residue in the recognition helix of the homeodomain, is likely to perturb HOXA13's DNA-binding properties, resulting in both a loss and a specific gain of function.
authors.affiliation: Departments of Human Genetics and Pediatrics, University of Michigan, Ann Arbor, MI, USA. innis@umich.edu
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Innis
authors.forename: Frances R
authors.initials: FR
authors.lastname: Goodman
authors.forename: Chiara
authors.initials: C
authors.lastname: Bacchelli
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Williams
authors.forename: Douglas P
authors.initials: DP
authors.lastname: Mortlock
authors.forename: Praveen
authors.initials: P
authors.lastname: Sateesh
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Scambler
authors.forename: Wendy
authors.initials: W
authors.lastname: McKinnon
authors.forename: Alan E
authors.initials: AE
authors.lastname: Guttmacher
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics*; D000483:Alleles; D001483:Base Sequence / Q000235:genetics; D005260:Female; D005532:Foot Deformities, Congenital / Q000235:genetics; D005801:Genes, Homeobox / Q000235:genetics*; D005835:Genitalia / Q000002:abnormalities; D006228:Hand Deformities, Congenital / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D008297:Male; D020125:Mutation, Missense / Q000235:genetics*; D010375:Pedigree; D011401:Promoter Regions, Genetic / Q000235:genetics*; D017384:Sequence Deletion / Q000235:genetics*; D013577:Syndrome
chemical_list: D018398:Homeodomain Proteins; C099959:homeobox protein HOXA13