Genetic and Clinical Features of Children with ?-Thalassemia Intermedia / 实用儿科临床杂志

ABSTRACT

Objective To analyze genetic and clinical features of 14 children with ?-thalassemia intermedia in Guangxi area.Methods ?-thalassemia genes,?-thalassemia genes,single nucleotide polymorphism(SNP) at position-158 of()~G?-globin gene,AT repeats polymorphisms of DNase I-hypersensitive site 2 of the ?-globin gene cluster locus control region(?-LCR-HS2) were detected by PCR techniques.Clinical data were analyzed.Results Genotype1.Seven cases were homozygous or compound heterozygous for nt-28(A→G).Among them,2 cases′ genotypes were nt-28/nt-28,1 case was ?~E/ nt-28,2 cases were ?~0/nt-28,1 case(?~0/nt-28) co-inherited()~G?158(T) and 1 case(?~0/nt-28) co-inherited simultaneously()~G?-158(T) and——SEA ?-thalassemia-1 genes.2.Three cases with ?~0/?~0 presented()~G?-158(T),and other 3 cases co-inherited——SEA ?-thalassemia-1 genes.3.One patient with ?~0/?~0 co-inherited()~G?-158(T) and——SEA ?-thalassemia-1 genes.4.Six cases carrying()~G?-158(T) had(AT)_9 N_(12)(AT)_(10) sequences in ?-LCR-HS2.PhenotypeThe values of Hb,MCV,HbF of 14 patients were(75.9?9.7) g/L,(68.9?5.9) fL,66.9%?16.3%,respectively.Except for 2 cases with genotypes of nt-28/nt-28 and 1 case with ?~E/nt-28 who had never been transfused,the others had more severe symptoms and required irregularly transfusion.Conclusions In the 14 children with ?-thalassemia intermedia from Guangxi area,nt-28(A→G),()~G?-158(T) and——SEA ?-thalassemia-1 gene are main alleviating gene factors.Incidence of(AT)_9 N_(12)(AT)_(10) sequence in ?-LCR-HS2 in these patients is high.Patients who are homozygous for nt-28 or compound heterozygous for ?~E have milder phenotypes.