Analysis Of Clinical Phenotype And Genotype Of 2 Patients With Glanzmann Thrombasthenia And Literature Review

Objective: To investigate the clinical phenotype and gene mutation characteristics of Glanzmann thrombasthenia(GT),to raise clinician’s awareness of the disease.Methods: Retrospectively analyzing of the clinical features,laboratory examination,the contents of glycoprotein Ⅱb/Ⅲa of platelets,gene sequencing results and family survey of two children diagnosed with GT in the pediatrics of the Affiliated Hospital of Zunyi Medical University from January 2016 to December 2018.And reviewing relevant literature and discussing.Results:1、For case 1 the age of onset was 1 month old,the diagnosed age was 3 years old.For case 2 the age of onset was 4 years old,the diagnosed age was 12 years old.Both were characterized by repeated skin ecchymosis and epistaxis.Case 2 had heavy bleeding at menarche.2、The parents of 2 cases were cousins.2 cases were G2P2,and compatriot older brothers had a similar history.3、2 cases were associated with moderate hemorrhagic anemia,normal platelet count and morphology,prolonged bleeding time,deficient clot retraction,normal coagulation function,and severely reduced platelet aggregation in response to adenosine diphosphate(ADP).4、Through flow cytometry test the contents of glycoprotein Ⅱb/Ⅲa of platelets,case 1showed no CD41 expression,CD61 positive rate was 1.3%,clinical diagnosis with type I GT.Case 2 CD41 positive rate was 31.3%,CD61 positive rate was 41.0%,clinical diagnosis with type Ⅲ GT.5、For case 1 gene sequencing 17 chromosome in ITGA2 B gene exon 4 c.480C> G:p.S160 R was homozygous missense mutation,parents were heterozygous mutation.Forcase 2 in the ITGA2 B gene exon 20 c.2077dupG: p.A693 F was homozygous cleavage mutation,the father was heterozygous mutation,and the mother failed to detect the gene.The two mutations were not reported at home and abroad by PUBMED and Wanfang Medical Network.Conclusions:1 、 The symptoms of Glanzmann thrombasthenia were mainly the skin and mucosal hemorrhage;adolescent women had menometrorrhagia.The patients with Glanzmann thrombasthenia tended to start from a young age,and the condition was prolonged and repeated.2、Flow cytometry was highly sensitive to detect glycoprotein Ⅱb/Ⅲa of platelets and can be used for early diagnosis and typing of GT.3 、C.480C> G: p.S160 R and c.2077dupG: p.A693 F mutations were newly discovered possible pathogenic mutations in ITGA2 B gene defect leaded to Glanzmann thrombasthenia.