Brachydactyly type B: clinical description, genetic mapping to chromosome 9q, and evidence for a shared ancestral mutation

Am J Hum Genet. 1999 Feb;64(2):570-7. doi: 10.1086/302249.

Abstract

Autosomal dominant brachydactyly type B (BDB) is characterized by nail aplasia with rudimentary or absent distal and middle phalanges. We describe two unrelated families with BDB. One family is English; the other family is Canadian but of English ancestry. We assigned the BDB locus in the Canadian family to an 18-cM interval on 9q, using linkage analysis (LOD score 3.5 at recombination fraction [theta] 0, for marker D9S938). Markers across this interval also cosegregated with the BDB phenotype in the English family (LOD score 2.1 at straight theta=0, for marker D9S277). Within this defined interval is a smaller (7.5-cM) region that contains 10 contiguous markers whose disease-associated haplotype is shared by the two families. This latter result suggests a common founder among families of English descent that are affected with BDB.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Activin Receptors, Type I*
  • Chromosome Mapping
  • Chromosomes, Human, Pair 9*
  • Female
  • Fingers / abnormalities*
  • Foot Deformities, Congenital / genetics*
  • Foot Deformities, Congenital / physiopathology
  • Genes, Dominant*
  • Hand Deformities, Congenital / genetics*
  • Hand Deformities, Congenital / physiopathology
  • Haplotypes
  • Humans
  • Male
  • Mutation*
  • Pedigree
  • Protein Serine-Threonine Kinases / genetics*
  • Receptor, Transforming Growth Factor-beta Type I
  • Receptors, Transforming Growth Factor beta / genetics*
  • Toes / abnormalities*

Substances

  • Receptors, Transforming Growth Factor beta
  • Protein Serine-Threonine Kinases
  • Activin Receptors, Type I
  • Receptor, Transforming Growth Factor-beta Type I