Molecular analysis of hemoglobinopathies in a large ethnic Hakka population in southern China

Abstract

Thalassemia is an inherited autosomal recessive disorder with microcytic hypochromic anemia resulting from reduced or absent synthesis of 1 or more of the globin chains of hemoglobin. This study provided the insight into prevalence and molecular characterization of thalassemia in Hakka population. 14,524 unrelated subjects were included in our study from January 2015 to November 2017. All the subjects were detected by hematological analysis, hemoglobin electrophoresis analysis, and molecular diagnosis (gap-polymerase chain reaction and flow-through hybridization technology). Data analysis was used to compare allele frequencies between the Hakka populations. Seven thousand four hundred twenty-two cases of microcytosis were found. The percentage of microcytosis in Meizhou, Ganzhou, and Heyuan was 50.91% (6738/13,236), 51.27% (445/868), and 56.90% (239/420), respectively. A total of 5516 mutant chromosomes were identified, including 3775 α-thalassemia and 1741 β-thalassemia. --SEA/αα was the most common α-thalassemia genotype, followed by -α3.7/αα and -α4.2/αα, accounted for 84.92% of α-thalassemia genotypes. Twelve kinds of mutations and 26 genotypes in β-thalassemia were found. IVS-II-654(C→T), CD41-42(-TCTT), −28(A→G), and CD17(A→T) alleles accounted for 92.65% of these mutations. IVS-II-654/N, CD41-42/N, -28/N, CD17/N genotypes accounted for 91.53% of β-thalassemia genotypes. 27 fetuses with at-risk pregnancies were subjected to prenatal diagnosis. Five fetuses were Bart's hydrops syndrome and 2 fetuses with β-thalassemia major. There were some differences in molecular characterization of thalassemia among Hakka people in different areas of southern China. Our results enriched the related information of thalassemia in the region, which provided valuable references for the prevention and control of thalassemia.

Molecular prevalence of thalassemia and hemoglobinopathies among the Lao Loum Group in the Lao People’s Democratic Republic

“…Consistent with a previous report, we found that β 0 ‐thalassemia is more common than β + ‐thalassemia. The two most common β‐‐thalassemia mutations in the Lao PDR populations are codon 41/42 (‐TTCT) and codon 17 (A‐T) which are similar to those found in Thailand, China, and South Vietnam …”

Gene Mutation Spectrum of Thalassemia Among Children in Yunnan Province

“…Hemoglobin electrophoresis was used to analyze the percent of hemoglobin Hbs A, A2, F, and any abnormal hemoglobin variant. The children with low HbA2 (<2.5%) values were considered possibly α-thalassemia carriers, with high HbA2 (>3.5%) values were considered possibly β-thalassemia carriers, respectively (13).…”

Molecular characterization of hemoglobinopathies and thalassemias in Northern Guangdong Province, China

“…However, the frequency is higher than that of the average level of Guangdong province (0.36%, P < .05), that of the average level of the 7 provinces in southern region of the Yangtze River (0.33%, P < .05), and that of the average level of the 7 provinces in northern region of the Yangtze River (0.17%, P < .05). [11] In this study, Hb Q-Thailand (HBA1: c.223 G > C) was the most frequent Hb variant (0.17%, 17/10,285) in Shaoguan. All Hb Q-Thailand cases were associated with -a 4.2 thalassemia and showed slight microcytosis.…”