title: Molecular characterization of a novel 27.6-kb deletion causing α(+) thalassemia in a Chinese family.
abstract: Over 80% of the α-thalassemia cases in southern China are caused by large deletions involving the α-globin gene cluster on chromosome 16p13.3. Here, we characterized a novel 27.6-kb deletion on the α-globin gene cluster in a Chinese family. Its breakpoints were detected to lie between coordinates 9079 and 36718 of the α-globin gene cluster (NG_000006.1), with a total of 27,640 nucleotides deleted. It was designated as -α (27.6) deletion. The proband is a compound heterozygote of --(SEA) and -α (27.6) and he displayed very mild hemoglobin H disease phenotype with Hb 7.9-9.3 g/dl. Phenotypic analysis on heterozygote of this deletion revealed it as α(+) mutation. It leads to a very mild phenotype as adult heterozygotes have normal hematological parameters with the values at the lower border of the normal range. RT-PCR analysis showed that the α-globin mRNA level of the heterozygotes was decreased when compared with that of normal people.
authors.affiliation: Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, People's Republic of China.
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Wei
authors.forename: Xuan
authors.initials: X
authors.lastname: Shang
authors.forename: De-Qin
authors.initials: DQ
authors.lastname: He
authors.forename: Ji-Wei
authors.initials: JW
authors.lastname: Huang
authors.forename: Xin-Hua
authors.initials: XH
authors.lastname: Zhang
authors.forename: Xiang-Min
authors.initials: XM
authors.lastname: Xu
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics*; D002675:Child, Preschool; D002872:Chromosome Deletion; D002885:Chromosomes, Human, Pair 16; D004252:DNA Mutational Analysis; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D010375:Pedigree; D017085:alpha-Thalassemia / Q000208:ethnology / Q000235:genetics*