Molecular Epidemiological Characterization and Health Burden of Thalassemias in the Chaoshan Region, People’s Republic of China

<p>Thalassemia is one of the most prevalent inherited disease in southern China. However, there have been only a few epidemiological studies of thalassemia in the Chaoshan region of Guangdong Province, People’s Republic of China (PRC). A total of 6231 unrelated subjects in two main geographical cities of the Chaoshan region was analyzed for thalassemia. Seven hundred and thirty-six cases of suspected thalassemia carriers with microcytosis [mean corpuscular volume (MCV) <82.0 fL] were found by complete blood cell (CBC) count, and were tested by reverse dot-blot gene chip to reveal a total of 331 mutant chromosomes, including 278 α-thalassemia (α-thal) alleles and 53 β-thalassemia (β-thal) alleles. The most common α-thal mutations were the Southeast Asian (– –^SEA), followed by the –α^3.7 (rightward) and –α^4.2 (leftward) deletions. The two most common β-thal mutations were <i>HBB</i>: c.316-197C>T and <i>HBB</i>: c.126_129delCTTT, accounting for 69.81% of the β-thal defects in the studied individuals. In addition, a rare mutation, Cap +1 (A>C) (<i>HBB</i>: c.-50A>C) was described for the first time in the Chaoshan region. Our results gave a heterozygote frequency of 5.31% for common α- and β-thal in the Chaoshan region, and also indicated a higher prevalence of thalassemia with a heterozygote frequency of 6.29% in Chaozhou, followed by Shantou (3.37%). This study provided a detailed prevalence and molecular characterization of thalassemia in the Chaoshan region, and will be valuable for developing a strategy for prevention of thalassemia and reducing excessive health care costs in this area.</p

The socio-demographic characteristics of blood donors from the Malabo Regional Hospital on Bioko Island, Equatorial Guinea, 2011–2013.

<p>The socio-demographic characteristics of blood donors from the Malabo Regional Hospital on Bioko Island, Equatorial Guinea, 2011–2013.</p

The co-infection seroprevalence of HIV, HBV, HCV and <i>Treponema pallidum</i> among blood donors on Bioko Island, Equatorial Guinea, 2011–2013.

<p>The co-infection seroprevalence of HIV, HBV, HCV and <i>Treponema pallidum</i> among blood donors on Bioko Island, Equatorial Guinea, 2011–2013.</p

The geographic location of our research population.

<p>Malabo city was divided into eight regions including the old city center (A), the presidential office and residential area (B), the public residential area from previous planning (C), the modern residential area with a low population density (D), the modern residential area with a high population density (E), the un-planned residential area with a different population density (F) and the un-planned residential area with a high population density (G). The rural area included Luba, Moka, Riaba and Baney on Bioko Island. </p

Geographic location of the Jiangxi province and three regional centers of our study.

<p>Geographic location of the Jiangxi province and three regional centers of our study.</p

The future health burden prediction in Jiangxi province.

<p>Data of population and Pregnancies/year was obtained from Web of Jiangxi Provincial government (<a href="http://www.gztj.gov.cn" target="_blank">http://www.gztj.gov.cn</a>); Southern area: Ganzhou region; Middle area: Ji'an region, Pingxiang region, Yichun region and Xinyu region; Northern area: Nanchang region, Jingdezhen region, Wuzhou region, Jiujiang region and Shangrao region. β-thalassemia M-I: β-thalassemia major or intermedia.</p

Geographic location of the Jiangxi province and three regional centers of our study.

<p>Geographic location of the Jiangxi province and three regional centers of our study.</p

Results of the survey of population prevalence of thalassemia among 9489 blood samples in the Jiangxi province.

a<p>Including three types of silent heterozygous mutation, −α^3.7/αα, −α^4.2/αα, and α^WSα/αα;</p>b<p>Including three types of heterozygous mutation (–SEA/αα, α^CSα/αα, α^QSα/αα) and a type of homozygous mutation −α^3.7/−α^3.7.</p

α-, β-thalassaemia alleles and their distribution among the three regions in Jiangxi province.

a<p>These numbers include silent heterozygous mutation, α-thalassemia trait, Hb H disease and α-thalassemia compound β-thalassemia;</p>b<p>These numbers include β-thalassemia trait and α-thalassemia compound β-thalassemia.</p

High Resolution Melting Analysis: A Rapid Screening and Typing Tool for Common β-Thalassemia Mutation in Chinese Population

<div><p>β-thalassemia is a common inherited disorder worldwide including southern China, and at least 45 distinct β-thalassemia mutations have been identified in China. High-resolution melting (HRM) assay was recently introduced as a rapid, inexpensive and effective method for genotyping. However, there was no systemic study on the diagnostic capability of HRM to identify β-thalassemia. Here, we used an improved HRM method to screen and type 12 common β-thalassemia mutations in Chinese, and the rapidity and reliability of this method was investigated. The whole PCR and HRM procedure could be completed in 40 min. The heterozygous mutations and 4 kinds of homozygous mutations could be readily differentiated from the melting curve except c.-78A>G heterozygote and c.-79A>G heterozygote. The diagnostic reliability of this HRM assay was evaluated on 756 pre-typed genomic DNA samples and 50 cases of blood spots on filter paper, which were collected from seven high prevalent provinces in southern China. If c.-78A>G heterozygote and c.-79A>G heterozygote were classified into the same group (c.-78&79 A>G heterozygote), the HRM method was in complete concordance with the reference method (reverse dot blot/DNA-sequencing). In a conclusion, the HRM method appears to be an accurate and sensitive method for the rapid screening and identification of β-thalassemia mutations. In the future, we suggest this technology to be used in neonatal blood spot screening program. It could enlarge the coverage of β-thalassemia screening program in China. At the same time, its value should be confirmed in prospectively clinical and epidemiological studies.</p></div