Telomere phenotypes in females with heterozygous mutations in the dyskeratosis congenita 1 (DKC1) gene

Hum Mutat. 2013 Nov;34(11):1481-5. doi: 10.1002/humu.22397. Epub 2013 Sep 11.


Dyskeratosis congenita (DC) is a telomere-mediated syndrome defined by mucocutaneous features. The X-linked mode of inheritance accounts for half the cases, and is thought to predominantly manifest in childhood as bone marrow failure. We identified two male probands who presented in the fifth decade with idiopathic pulmonary fibrosis and cancer. Their pedigrees displayed consecutively affected generations. Five of six females (83%) manifested mucocutaneous features of DC, and two had wound-healing complications. No mutations in autosomal dominant telomere genes were present, but exome sequencing revealed novel variants in the X-chromosome DKC1 gene that predicted missense mutations in conserved residues, p.Thr49Ser and p.Pro409Arg. Variants segregated with the telomere phenotype, and affected females were heterozygotes, showing skewed X-inactivation. Telomerase RNA levels were compromised in cells from DKC1 mutation carriers, consistent with their pathogenic role. These findings indicate that females with heterozygous DKC1 mutations may be at increased risk for developing penetrant telomere phenotypes that, at times, may be associated with clinical morbidity.

Keywords: DKC1; Dyskeratosis congenita; myelodysplastic syndrome; pulmonary fibrosis; telomerase.

Publication types

  • Case Reports
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / genetics*
  • Dyskeratosis Congenita / diagnosis
  • Dyskeratosis Congenita / genetics*
  • Female
  • Heterozygote*
  • Humans
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Mutation*
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics*
  • Phenotype*
  • Sequence Alignment
  • Telomere / genetics*


  • Cell Cycle Proteins
  • DKC1 protein, human
  • Nuclear Proteins