Analysis of phenotype and genotype in eight Chinese pedigrees with glanzmann thrombastheuia / 中华检验医学杂志

ABSTRACT

Objective To study the GPⅡb/Ⅲa gene mutations of eight glanzmann thrombasthenia(GT) pedigrees. Methods Responses of eight probands to different agonists were observed by platelet aggregation test and the amount of αⅡb and β3 was determined by flow cytometry. All the exons of Ⅱb and Ⅲ a genes were amplified by PCR followed by sequencing for mutational screening. Further analysis of the normal population excluded the possibility of mutational sites as a polymorphism. Results Eight probands showed normal PLT counts, dispersion of the platelet particles without aggregation, prolonged bleeding time and severely reduced platelet aggregation in response to the physiological agonists- ADP, epinephrine, and collagen, but relatively normal aggregation of PLT in response to ristocetin. Flow cytometry showed that all probande were Ⅰ type GT, except that proband 2 was Ⅲ type GT and proband 6 was Ⅱ type GT. The sequencing results showed that twelve different types mutations were present in eight probands, including GIOA, Gl412T, GII99A, 1525deiC, G2223T, C2671T, 2930delG, IVSI5 (-1) delG, A2334C, C1750T, 69-79del and CA70A. We were not able to detected any mutations in GP Ⅱb/Ⅲa gone on proband 3. Conclusions GT is mainly caused by GPⅡb/Ⅲa gene mutations. G10A, 69-79del, C470A,G1412T, G2223T, C2671T and 1525delC were the novel mutations causing GT.