INTRODUCTION: The HKαα (Hong Kong αα) allele containing both the -α3.7 and αααanti4.2 is an unusual rearrangement of the α globin gene cluster. Currently, αααanti4.2 fragments cannot be detected through the routine thalassemia diagnostic kit. The genotype of -α3.7/αα, HKαα/-α3.7 and HKαα/αα is entirely the result of -α3.7/αα by the gap-polymerase chain reaction (gap-PCR), which would cause some cases of the HKαα allele to be mistaken as -α3.7/αα. METHODS: Genetic diagnosis was performed in 17166 cases, using single PCR and two-round nested PCR to detect the HKαα allele in 895 cases. It showed -α3.7 and α2 bands by gap-PCR, and reverse dot-blot assays were performed to detect the non-deletional α thalassemia point mutations and β thalassemia point mutations. RESULTS: The HKαα allele was found in 56 samples. The rates of HKαα/αα, HKαα/-α3.7 and HKαα/--SEA were 4.92%, 0.67% and 0.67%. The rate of the HKαα allele was 0.33% in a southern Chinese population. In the HKαα/αα thalassemia group, the levels of hemoglobin (Hb), mean cell volume (MCV), and mean cell hemoglobin (MCH) were similar to the -α3.7/αα thalassemia group. The hematology of the HKαα/--SEA carriers was similar with the α0 thalassemia carriers, and Hb is usually over 100 g/l. The two families carrying HKαα/--SEA genotype chose to retain the fetuses in our study. CONCLUSIONS: There was a certain proportion of the HKαα allele in southern Chinese population, and the hematologic manifestations were mild. Differential diagnosis of HKαα genotype from -α3.7/αα can provide more accurate genetic diagnosis and clinical thalassemia genetic counseling. IJCEP
INTRODUCTION: The HKαα (Hong Kong αα) allele containing both the -α3.7 and αααanti4.2 is an unusual rearrangement of the α globin gene cluster. Currently, αααanti4.2 fragments cannot be detected through the routine thalassemia diagnostic kit. The genotype of -α3.7/αα, HKαα/-α3.7 and HKαα/αα is entirely the result of -α3.7/αα by the gap-polymerase chain reaction (gap-PCR), which would cause some cases of the HKαα allele to be mistaken as -α3.7/αα. METHODS: Genetic diagnosis was performed in 17166 cases, using single PCR and two-round nested PCR to detect the HKαα allele in 895 cases. It showed -α3.7 and α2 bands by gap-PCR, and reverse dot-blot assays were performed to detect the non-deletional α thalassemia point mutations and β thalassemia point mutations. RESULTS: The HKαα allele was found in 56 samples. The rates of HKαα/αα, HKαα/-α3.7 and HKαα/--SEA were 4.92%, 0.67% and 0.67%. The rate of the HKαα allele was 0.33% in a southern Chinese population. In the HKαα/αα thalassemia group, the levels of hemoglobin (Hb), mean cell volume (MCV), and mean cell hemoglobin (MCH) were similar to the -α3.7/αα thalassemia group. The hematology of the HKαα/--SEA carriers was similar with the α0 thalassemia carriers, and Hb is usually over 100 g/l. The two families carrying HKαα/--SEA genotype chose to retain the fetuses in our study. CONCLUSIONS: There was a certain proportion of the HKαα allele in southern Chinese population, and the hematologic manifestations were mild. Differential diagnosis of HKαα genotype from -α3.7/αα can provide more accurate genetic diagnosis and clinical thalassemia genetic counseling. IJCEP
Authors: Wen Wang; Edmond S K Ma; Amy Y Y Chan; John Prior; Wendy N Erber; Li C Chan; David H K Chui; Samuel S Chong Journal: Clin Chem Date: 2003-10 Impact factor: 8.327
Authors: X M Xu; Y Q Zhou; G X Luo; C Liao; M Zhou; P Y Chen; J P Lu; S Q Jia; G F Xiao; X Shen; J Li; H P Chen; Y Y Xia; Y X Wen; Q H Mo; W D Li; Y Y Li; L W Zhuo; Z Q Wang; Y J Chen; C H Qin; M Zhong Journal: J Clin Pathol Date: 2004-05 Impact factor: 3.411