DKC1 gene mutation in a Taiwanese kindred with X-linked dyskeratosis congenita.
Dyskeratosis congenita (DKC) is a rare inherited disease characterized by the triad of abnormal skin pigmentation, nail dystrophy, and mucosal leukoplakia. Recent studies demonstrated mutations in the DKC1 gene encoding a protein named dyskerin, which is a component of human telomerase. In addition to the hypothesized function of pseudouridination in rRNA biosynthesis, ribosomal subunit assembly, and/or centromere/ microtubule binding, lower levels of telomerase activity in cells from patients with X-linked DKC have been observed. We report the mutation analysis of a Taiwanese family with X-linked DKC. The patient was a 19-year-old man who presented with progressive reticulate hyperpigmentation, nail dystrophy, alopecia, leukoplakia of the tongue, and pancytopenia. He died of enterocolitis and Escherichia coli sepsis at the age of 20 years. Only his mother's DNA was available for mutation analysis, which revealed a nucleotide transition of C to T (1058 C --> T), a hotspot mutation in DKC, resulting in an amino acid change from alanine to valine (A353V) in the DKC1 gene. Recent advances in the research of telomerase and its implications in the human aging process and cancer are discussed.
Lin
Jeng-Hsien
JH
Department of Dermatology, National Cheng Kung University Hospital, Tainan, Taiwan.
Lee
J Yu-Yun
JY
Tsao
Chao-Jung
CJ
Chao
Sheau-Chiou
SC
D000328:Adult; D018797:Cell Cycle Proteins / Q000235:genetics*; D041321:Chromosomes, Human, X; D019871:Dyskeratosis Congenita / Q000235:genetics*; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics*; D016615:Telomere
D018797:Cell Cycle Proteins; C112148:DKC1 protein, human; D009687:Nuclear Proteins