Mapping and characterization of the X-linked dyskeratosis congenita (DKC) gene.
We report the precise mapping and characterization of the genomic structure of the human homolog of the rat gene for the nucleolar protein NAP57, which has been reported to be responsible for X-linked dyskeratosis congenita (DKC). This single-copy gene, now called DKC, is transcribed from a CpG island 60 kb centromeric to the factor VIII gene in distal Xq28 and lies tail to tail with the palmitoylated erythrocyte membrane protein gene, MPP1. DKC comprises 15 exons spanning at least 16 kb and is transcribed into a widely expressed 2.6-kb message. Several functional motifs of DKC are assigned to coding sequences specified by individual exons. Analysis of normal female DNA revealed the presence of two polymorphisms in the DKC exons, while mutation analysis of a DKC patient identified a novel single amino acid missense mutation in exon 4. The latter together with exon 3 contain five of the six missense mutations reported so far in the DKC gene.
Hassock
S
S
Medical and Molecular Genetics, UMDS, London, SE1 9RT, United Kingdom.
Vetrie
D
D
Giannelli
F
F
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018797:Cell Cycle Proteins / Q000235:genetics*; D002874:Chromosome Mapping; D004247:DNA; D019871:Dyskeratosis Congenita / Q000235:genetics*; D005091:Exons; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D009687:Nuclear Proteins / Q000235:genetics*; D011110:Polymorphism, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D051381:Rats; D014960:X Chromosome
D018797:Cell Cycle Proteins; C112148:DKC1 protein, human; D009687:Nuclear Proteins; D012333:RNA, Messenger; D004247:DNA