Reduced penetrance in a family with X-linked dominant chondrodysplasia punctata

Eur J Med Genet. 2007 Sep-Oct;50(5):392-8. doi: 10.1016/j.ejmg.2007.05.004. Epub 2007 Jun 3.

Abstract

X-linked dominant chondrodysplasia punctata (Conradi-Hünermann disease, CDPX2) is characterised by short stature, stippled epiphyses, cataracts, ichthyosiform erythroderma and patchy alopecia of the scalp. The disorder is caused by mutations within the emopamil binding protein (EBP) gene encoding a 3beta-hydroxysteroid-Delta(8),Delta(7)-isomerase. The intrafamilial variation of disease severity is a known feature of CDPX2 probably caused by skewed X-inactivation. We report on a female fetus with typical symptoms of CDPX2 such as short limbs, postaxial polydactyly, ichthyotic skin lesions and punctate calcifications. Molecular genetic analysis of the EBP gene revealed a nonsense mutation (c.328C>T, p.R110X), which was previously detected in one CDPX2 patient and in a second female patient, who was only affected on one body side and erroneously diagnosed as CHILD syndrome. Surprisingly, the mother of our fetus carries the same mutation without having any signs of CDPX2. X-inactivation studies did not reveal any evidence of skewing neither in the mother nor in the fetus.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Chondrodysplasia Punctata / enzymology
  • Chondrodysplasia Punctata / genetics*
  • Chromosomes, Human, X / genetics
  • Codon, Nonsense
  • Female
  • Genes, Dominant
  • Genetic Diseases, X-Linked / enzymology
  • Genetic Diseases, X-Linked / genetics*
  • Humans
  • Penetrance
  • Phenotype
  • Pregnancy
  • Prenatal Diagnosis
  • Steroid Isomerases / genetics
  • X Chromosome Inactivation

Substances

  • Codon, Nonsense
  • Steroid Isomerases
  • EBP protein, human