Results of thalassemia screening and genetic diagnosis for 13 738 pregnant women / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To report on the result of thalassemia screening and genetic diagnosis for pregnant women from Guiyang region.</p><p><b>METHODS</b>Prenatal screening for thalassemia was carried out based on erythrocyte parameters and hemoglobin electrophoresis. Single-tube multiplex GAP-PCR and PCR-reverse dot blot hybridization were performed on suspected cases to identify common alpha- and beta- thalassemia mutations, and direct sequencing was used for identifying rare mutations.</p><p><b>RESULTS</b>Among 13 738 pregnant women, 1745 (12.70%) were suspected as thalassemia. In terms of native place, the provinces with highest screening-positive rates were Guangxi, Guangdong, Jiangxi and Guizhou. And the ethnic groups with highest screening-positive rates were Zhuang, Li, and Buyi. Among 801 women subjected to genetic testing, 457 (57.05%) were diagnosed with thalassemia. In total 9 genotypes of alpha- thalassemia were detected, with the most common genotypes being --/alpha alpha (63.35%), - alpha/alpha alpha (19.37%) and - alpha/alpha alpha (8.90%). Eleven genotypes of beta- thalassemia were detected, with the most common genotypes being CD17/N (42.91%), CD41-42/N (32.46%) and IVS-II-654/N (11.94%). Two cases were detected with rare beta-thalassemia mutations (CD54-58/N and IVS-I-130/N).</p><p><b>CONCLUSION</b>The screening-positive rate of thalassemia among pregnant women in Guiyang region is relatively high. The rates have shown substantial difference in terms of native place and ethnic group. Thalassemia-related mutations in Guizhou region have a diverse spectrum, which showed certain difference from those of other regions.</p>

Analysis of β -thalassemia mutations in Guizhou Province / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the spectrum of β -thalassemia mutations in Guizhou Province.</p><p><b>METHODS</b>For 542 individuals suspected to have β -thalassemia by decreased mean corpuscular volume (MCV) and corpuscle hemoglobin (MCH) by routine blood test and hemoglobin electrophoresis, reverse dot blot hybridization (RDB) was performed to detect 17 known β -thalassemia mutations, including 8 common and 9 rare mutations. For cases where no mutation was identified, the entire human β -globin gene was screened to find other rare mutations. The distribution and frequencies of detected β -thalassemia mutations were then analyzed.</p><p><b>RESULTS</b>A total of 460 individuals were diagnosed as β -thalassemia by DNA analysis, which included 352 heterozygotes, 67 compound heterozygotes and 41 mutant homozygotes. A total of 12 β -thalassemia mutations were detected in these individuals. The mutations have ranked from high to low frequency as: CD17 (40.74%), CD41-42 (33.69%), IVS-II-654 (13.76%), -28 (3.70%), β E (3.35%), CD71-72(1.94%), CD43 (1.06%), IVS-I-1 (0.71%), CD27-28 (0.35%), -29(0.35%), CAP (0.18%), and CD121 (0.18%). The former six mutations have accounted for 97.18% of all. CD121 (GAA> TAA) detected from a heterozygote, as a dominant mutation, has been firstly found in the Chinese population.</p><p><b>CONCLUSION</b>The spectrum of β -thalassemia in Guizhou Province showed certain distinct characteristics, with CD17 being the most common mutation. The newly discovered mutation of CD121 has expanded the spectrum of β -thalassemia in Chinese population. Our result may provide valuable information for the prevention and control of β -thalassemia in Guizhou.</p>