A 0.7 Mb de novo duplication at 7q21.3 including the genes DLX5 and DLX6 in a patient with split-hand/split-foot malformation

Am J Med Genet A. 2012 Dec;158A(12):3201-6. doi: 10.1002/ajmg.a.35644. Epub 2012 Nov 20.

Abstract

Split-hand/split-foot malformation (SHFM1) has been reported to be caused by deletions, duplications or rearrangements involving the 7q21.3 region harboring DSS1, DLX5, and DLX6. We report on a female patient with unilateral syndactyly of the third and fourth fingers of the right hand and overgrowth and lateral deviation of the right great toe. There was a split foot malformation on the right, with absent fifth toe. The left hand was apparently normal and left foot was intact. The patient has no hearing loss. We performed conventional G-banding karyotype analysis, array comparative genomic hybridization (aCGH) and fluorescence in situ hybridization (FISH). G-banding karyotype result was normal 46,XX. However, a duplication of 719 kb (96,303,736-97,022,335; NCBI build36/hg18, March 2006) was identified at the 7q21.3 region by aCGH. The array result was also confirmed by FISH analysis. The duplicated region harbors only DLX5 and DLX6, which are known for their role in SHFM1. Additionally, FISH analysis of parental samples showed de novo origin of this abnormality in the patient. This is the first report that highlights the duplication of 719 kb at 7q21.3, harboring only DLX5 and DLX6 associated with the SHFM1 phenotype.

Publication types

  • Case Reports

MeSH terms

  • Chromosomes, Human, Pair 7*
  • Female
  • Genes, Duplicate*
  • Homeodomain Proteins / genetics*
  • Humans
  • Infant
  • Limb Deformities, Congenital / genetics*
  • Transcription Factors / genetics*

Substances

  • DLX5 protein, human
  • DLX6 protein, human
  • Homeodomain Proteins
  • Transcription Factors

Supplementary concepts

  • Ectrodactyly