フイブリノゲンγ鎖における遺伝子多型の検討

In the gene of human fibrinogen gamma chain, nucleotide poly(di)morphism has been reported at eight different positions. Among them, nucleotide 2543 is the middle base of the codon which encords residue 88 resulting in an amino acid substitution of Lysine to lsoleucine. However remaining seven mutations are silent. We examined frequency of genomic polymorphism for gamma chain nucleotide 2543 by DNA sequencing and effect of the amino acid substitution on fibrinogen function. DNA was isolated from peripheral nucleated cells of 11healthy volunteers and one patient with dysfibrinogenemia and the fourth exon of gamma chain containing the nucleotide 2543 was amplified by polymerase chain reaction(PCR). Nucleotide sequence was directry analyzed by Dye Deoxy Terminator method using an ABI 373A DNA sequencer. The nucleotide 2543 was A in all 12 samples. We investigated gamma chain sequence of a case of dysfibrinogenemia and found that the nucleotide 2543 was homozygous for A but heterozygous for G and C at nucleotide 9380, resulted in the substitution of Aspartic acid and Histidine. We conclude that Lysine at residue 88 of gamma chain is wild type and lsoleucine is a rare mutation. It was also suggested that this polymorphism was not responsible for the pathogenesis of the dysfibrinogenemia.Article紀要 20: 31-36(1995)departmental bulletin pape