Investigation on gene mutation from hereditary protein S deficiency pedigree

Abstract

Objective To identify the clinical phenotypic diagnosis and gene mutation detection of two kindreds with PS deficiency. MethodsPS: A was measured by chromogenic substrate method;TPS:Ag, FPS: Ag levels were measured by ELISA method; PS gene(PROS1 gene)was detected by amplifying 15 exons and flanking intron sequences from the propositus with PCR method. PCR products were purified and directly sequenced. Results For propositus 1,PS: A was 48.6% ,TPS: Ag was 136 mg/L, FPS : Ag was 41 mg/L, PROSI gene exon 2 was in c. Heterozygous base substitutions was detected in C121T locus, which led to Arg-1Cys (R-1C) heterozygous roissense mutation encoded in PS proteins. For propositus 2, PS: A was 29.2%, TPS: Ag was 83 mg/L, FPS: Ag was 26 mg/L, PROSI gene exon 14 was in c. Heterozygous base substitutions was identified in CI687T locus, in which Gln.522Stop heterozygous nonsense mutation was encoded in PS proteins. Conclusions c. C121T is a novel mutation locus detected in PROS1 gene. This heterozygous mutation could lead to type Ⅱ PS hereditary deficiency, while c. C1687T heterozygous mutation could bring about type Ⅰ PS hereditary deficiency. Key words: Protein S deficiency; Pedigree; Blood proteins; Mutation