Two homozygous missense mutations in ITGB3 gene as a cause of Glanzmann Thrombasthenia in four consanguineous Pakistani pedigrees.
Int J Lab Hematol
; 42(5): 628-635, 2020 Oct.
Article
en En
| MEDLINE
| ID: mdl-32558238
ABSTRACT
INTRODUCTION:
Glanzmann thrombasthenia (GT) is most common of inherited platelet disorders, resulting from quantitative/qualitative defects in platelet surface integrin αIIbß3, encoded by ITGA2B and ITGB3 genes. Little is known about clinical and molecular characteristics of GT patients from highly consanguineous Pakistani population.METHODS:
This study analyzed the clinical and molecular spectrum of six GT patients from four unrelated but consanguineous families. Platelet surface expression of αIIbß3 integrin was determined using flow cytometry analysis. ITGA2B and ITGB3 genes were screened for causative mutations by DNA sequencing. Detected mutations were characterized for their pathogenicity using a variety of in silico tools.RESULTS:
Glanzmann thrombasthenia patients in this study generally presented early in life, had a severe course of clinical disease with transfusion dependency for management of bleeding episodes. Molecular analysis revealed 2 homozygous missense mutations in ITGB3 gene, c.422 AËG (p.Y141C) in three GT patients from a single pedigree with familial segregation and c.1641 C>G (p.C547W) in three unrelated GT patients from three families manifesting type I GT with severe reduction in platelet αIIbß3 levels. In silico pathogenicity predictions, multiple sequence alignment and 3D protein modeling unanimously suggested deleterious nature of the detected mutations, possibly due to aberrant disulfide bonding. Of note, clinical diversity was observed even among GT patients with same mutation in GT1 family.CONCLUSION:
This study provides an initial yet important account of clinical and genetic characterization of GT in local patients which may spark further studies to help molecular diagnosis, optimal disease management, and genetic counseling based prevention efforts.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Trombastenia
/
Mutación Missense
/
Integrina beta3
/
Homocigoto
Tipo de estudio:
Prognostic_studies
/
Qualitative_research
Límite:
Female
/
Humans
/
Male
País/Región como asunto:
Asia
Idioma:
En
Revista:
Int J Lab Hematol
Asunto de la revista:
HEMATOLOGIA
Año:
2020
Tipo del documento:
Article
País de afiliación:
Pakistán