Evidence that Smith-McCort dysplasia and Dyggve-Melchior-Clausen dysplasia are allelic disorders that result from mutations in a gene on chromosome 18q12.

Ehtesham N, Cantor RM, King LM, Reinker K, Powell BR, Shanske A, Unger S, Rimoin DL, Cohn DH
Am J Hum Genet. 2002 71 (4): 947-51

PMID: 12161821 · PMCID: PMC378548 · DOI:10.1086/342669

Smith-McCort dysplasia is a rare autosomal recessive osteochondrodysplasia characterized by short limbs and a short trunk with a barrel-shaped chest. The radiographic phenotype includes platyspondyly, generalized abnormalities of the epiphyses and metaphyses, and a distinctive lacy appearance of the iliac crest. We performed a genomewide scan in a consanguineous family from Guam and found evidence of linkage to loci on chromosome 18q12. Analysis of a second, smaller family was also consistent with linkage to this region, producing a maximum combined two-point LOD score of 3.04 at a recombination fraction of 0 for the marker at locus D18S450. A 10.7-cM region containing the disease gene was defined by recombination events in two affected individuals in the larger family. Furthermore, all affected children in the larger family were homozygous for a subset of marker loci within this region, defining a 1.5-cM interval likely to contain the defective gene. Analysis of three small, unrelated families with Dyggve-Melchior-Clausen syndrome, a radiographically identical disorder with the additional clinical finding of mental retardation, provided evidence of linkage to the same region, a result consistent with the hypothesis that the two disorders are allelic.

MeSH Terms (9)

Alleles Chromosome Mapping Chromosomes, Human, Pair 18 Female Humans Male Mutation Osteochondrodysplasias Pedigree

Connections (1)

This publication is referenced by other Labnodes entities: