Molecular characterization of a family with beta-thalassemia intermedia / 中华检验医学杂志

ABSTRACT

Objective To analyze a rare genotype with β-thalassemia intermadia.Methods Phenotypic analysis was performed using routine hematological tests to measure red blood cell parameters and high performance liquid chromatography (HPLC)was used to measure hemoglobin fractions.The β-globin gene mutations were conducted using reverse-dot-blot and DNA sequencing of the breakpoint region were characterized with gap-PCR.Results The proband had a trait of thalassemia intermedia with reduced hemoglobin (86 g/L).The proband's father had a trait of microcytic hypochromic with reduced mean corpuscular volume(MCV),mean corpuscular hemoglobin (MCH) (63.7 fl and 20.4 pg,respectively) and an elevated level of HbA2.He had the phenotype of heterozygosity for β-thalassemia.The preband's mother,grandmother and sister had a trait of heterezygote for hereditary persistence of fetal hemoglobin (HPFH) with elevated level of HbF,which were 28.3%,21.1% and 33.7%,respectively.After molecular characterization of the family members,the proband was identified as a patient with β-thalassemia intermedia caused by co-existence of β-thalassemia(β41-42) and HPFH-6.The father was heterozygoas for β-thaiassemia (β41-42/βN) and the mother,grandmother and sister were all heterozygons for HPFH-6.Condusions A rare β-thalassemia intermedia case resulting from compound heterezygote of β41-42 with HPFH-6 is found.This study may provide clinical experiences for antenatal diagnosis.