Molecular characterization of a novel 27.6-kb deletion causing α(+) thalassemia in a Chinese family.
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.
Wei
Xiao-Feng
XF
Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, People's Republic of China.
Shang
Xuan
X
He
De-Qin
DQ
Huang
Ji-Wei
JW
Zhang
Xin-Hua
XH
Xu
Xiang-Min
XM
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*