Molecular Spectrum, Ethnic and Geographical Distribution of Thalassemia in the Southern Area of Hainan, China

Abstract

BackgroundThalassemia is one of the most common genetic diseases in southern China. Accurate population frequency data regarding the occurrence and distribution of thalassemia are important for designing appropriate prevention strategies for thalassemia. This study aims to reveal the molecular spectrum, ethnic and geographical distribution of thalassemia in the southern area of Hainan Province, China.MethodsA total of 9813 suspected carriers of thalassemia were screened for genetic analysis by using the PCR-reverse dot blot hybridization method targeting three known deletions of α-thalassemias (--SEA, -α3.7, and -α4.2), three nondeletional mutations of α-thalassaemias (αCS, αQS, and αWS) and the 17 most common mutations of β-thalassaemias in the Chinese population.ResultsApproximately 6,924 subjects were genetically diagnosed as thalassemia carriers or patients, including 5812 cases of α-thalassemia (83.9%), 369 cases of β-thalassemia (5.3%), and 743 cases of α-composite β-thalassemia (10.7%). A total of 21 distinct genotypes were identified among the 5,812 α-thalassemia carriers, -α4.2/αα, -α3.7/αα, and -α3.7/-α4.2 were the most common α-thalassemia genotypes. The most frequent β-thalassemia genotype was βCD41−42/βN, with a notable proportion of 69.6%, followed by the β−28M/βN, βIVS−II−654/βN, βCD71−72/βN, βE/βN, and βCD17/βN genotypes. In addition, 37 genotypes were detected among the 743 cases of both α- and β-thalassemia mutations. The α-thalassemia genotypes were most commonly found in the Li people, who accounted for 73.5% of α-thalassemia carriers. The β-thalassemia genotypes were most commonly identified in the Han people, who accounted for 59.4% of β-thalassemia carriers. Among the subjects carrying both α- and β-thalassemia variations, only three ethnic minorities were identified, including the Li, Han, and Miao people, accounting for 82.0, 17.4, and 0.7%, respectively.ConclusionsOur study indicates that there is high genetic heterogeneity, geographical and ethnic differences in thalassemia in populations in the southern area of Hainan Province. These findings will be helpful in guiding genetic counseling and prenatal diagnosis of thalassemia in Hainan Province.

Genotypic spectrum of α-thalassemia and β-thalassemia in newborns of the Li minority in Hainan province, China

“…The data of the present study are in line with those of previous studies, and α-thalassemia is the major type of thalassemia in the Li minority ( 14 , 15 ). The proportions of different subtypes of α thalassemia and β-thalassemia are mainly consistent with one recent study carried out in childbearing age adults of the Li minority ( 15 ), particularly for the top two genotypes in α thalassemia (−α 4.2 /αα and −α 3.7 /αα) and top three in β-thalassemia (β CD41–42 /β N , β −28 /β N and β IVS−II−654 /β N ).…”

“…The tradition and economic status of the Li people remain similar due to their concentrated residence. Certain studies have shown that the Li people have a higher prevalence of thalassemia than other minorities (13)(14)(15). However, most studies have been carried out in Li's adults, in whom the genotypes might be different from those of newborns due to survivor bias, which hampers precise and immediate treatment marking and proper prevention policy design.…”

Molecular spectrum of α‐ and β‐thalassemia among individuals of reproductive age in the Zhuhai region of southern China

“…The top three most common β‐globin mutations in the Zhuhai region were CD41/42 (‐TCTT), IVS‐II‐654 (C>T) and TATAbox‐28, which accounted for 76.30% of all β‐thalassemia mutations. The most common mutation was CD41/42 (‐TCTT), which was consistent with data from Guangdong and several nearby provinces 6,12,13,21,22 . In other provinces, such as Hunan, Yunnan and Fujian, IVS‐II‐654 (C>T) was the most common mutation, whilst CD41/42 (‐TCTT) was the second most common 23,24,25 .…”

“…The most common mutation was CD41/42 (-TCTT), which was consistent with data from Guangdong and several nearby provinces. 6,12,13,21,22 In other provinces, such as Hunan, Yunnan and Fujian, IVS-II-654 (C>T) was the most common mutation, whilst CD41/42 (-TCTT) was the second most common. 23,24,25 These studies indicated that the common and widespread mutations were similar across southern China, with diverse frequencies.…”

A rare case of schizophrenia coexistence with antiphospholipid syndrome, β-thalassemia, and monoclonal gammopathy of undetermined significance

“…β-thalassemia is a group of genetic abnormalities in humans that range from asymptomatic to severe anemia. Southern China has a high incidence of the disease, and the most common mutation for β-thalassemia is CD41/42 (46)(47)(48). There have been case reports of β-thalassemia coexisting with psychiatric diseases in some Mediterranean families.…”