Analysis of HKαα Genotype and Hematological Characteristics in South Guangxi / 中国实验血液学杂志

OBJECTIVE@#To investigate the detection rate and hematologic phenotype of HKαα thalassemia in south Guangxi, in order to provide reference for the prevention and control of thalassemia and prenatal and postnatal care consultation in this region.@*METHODS@#Gene testing was performed on pre-marital medical examinations, pre-pregnancy eugenic health examinations, prenatal examinations and hospitalized thalassemia-positive persons in south of Guangxi, and the results were analyzed.@*RESULTS@#A total of 183 190 thalassemia patients were included in this study, the age was mainly concentrated in 26-35 years old (101 709 cases, accounting for 55.521%), and 40 HKαα mutations were detected, detection rate was 0.022%, including 5 cases in Nanning, 22 cases in Qinzhou, 2 cases in Fangchenggang, 11 cases in Beihai. A total of 29 ethnic groups were included in the survey, but HKαα gene was observed only in Han nationality (0.0380%) and Zhuang nationality (0.0068%). A total of 8 genotypes carrying HKαα mutations were detected in this study ( HKαα/--SEA, βN/ βN, HKαα/αα, β-28/ βN, HKαα/αα, β-50/ βN, HKαα/αα, βCD17/ βN, HKαα/αα, βCD27/28/β N, HKαα/αα, βCD41-42/ βN, HKαα/αα, βCD71-72/ βN, and HKαα/αα, βN/ βN). Except for most cases with HKαα/αα, βN/ βN genotypes with no significant changes in the hematological indexes, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) of other genotypes were decreased, showing microcytic hypochromic performance, mild anemia or no anemia.@*CONCLUSION@#HKαα carrier is often misdiagnosed as -α3.7 carrier, which easily leads to missed diagnosis or misdiagnosis. Therefore, it is necessary to continuously improve the diagnostic level of laboratory testing personnels and genetic counselors to avoid unnecessary interventional puncture operations and birth of children with moderate and severe thalassemia.

Gene Mutation Types of Thalassemia in Chongzuo Childbearing-age Population of Guangxi Zhuang Autonomous Region of China / 中国实验血液学杂志

OBJECTIVE@#To investigate the gene mutation and genotype distribution of thalassemia in the population of childbearing age in Chongzuo area of Guangxi.@*METHODS@#Six α-thalassemia and 17 β-thalassemia gene mutations common in Chinese were detected by gap-polymerase chain reaction (gap-PCR) combined with agarose gel eletrophoresis and reserve dot bolt hybridization in 29 266 cases of child-bearing age suspected of thalassemia.@*RESULTS@#A total of 19 128 (65.36%) cases were identified with thalassemia. The detection rate of α-thalassemia, β-thalassemia and α-combining β-thalassemia was 45.25% (13 242/29 266), 15.47% (4 526/29 266) and 4.65% (1 360/29 266), respectively. A total carrying rate of 8 kinds of α-thalassemia gene mutations was 26.74% (15 649/58 532), including 12.51% for --SEA, followed by 5.70% for -α3.7, and 0.24% for --Thai. Among 32 α-thalassemia genotypes, the most common five were --SEA/αα, -α3.7/αα, αCSα/αα, -α4.2/αα and αWSα/αα, accounting for 47.27%, 18.31%, 8.56%, 8.52% and 7.91%, respectively, as well as 0.97% for --Thai/αα. A total carrying rate of 13 kinds of β-thalassemia gene mutations was 10.07% (5 897/58 532), including 3.63% for CD41-42, followed by 2.55% for CD17, and 0.003% for -50 (G>A). Among 17 β-thalassemia genotypes, the most common six were CD41-42/N, CD17/N, CD71-72/N, CD26/N, 28/N and IVSI-1/N, accounting for 36.15%, 25.81%, 9.43%, 8.18%, 8.09% and 7.75%. The homozygous genotype CD26/CD26 [hemoglobin (Hb): 121 g/L] and -28/-28 (Hb: 56 g/L) were respectively detected in one case, and double heterozygous genotype were detected in 5 cases, including 3 cases of CD41-42/CD26 (Hb: 41 g/L, 51 g/L, 63 g/L, respectively), 1 case of -28/IVSI-1 (Hb: 53 g/L), and 1 case of CD71-72/CD26 (Hb: 89 g/L), in which patients with moderate or severe anemia had a history of blood transfusion. Among 104 α-combining β-thalassemia genotypes, the most common were --SEA/αα, -α3.7/αα combining CD41-42/N and --SEA/αα combining CD17/N, accounting for 12.13%, 9.63% and 9.26%, respectively. In addition, 1 case of --SEA/-α3.7 combining -28/IVSI-1 (Hb: 83 g/L) and 1 case of -α3.7/αα combining CD41-42/ CD41-42 (Hb: 110 g/L) were detected without history of blood transfusion, while 1 case of αWSα/αα combining CD41-42/CD17 (Hb: 79 g/L) and 1 case of --SEA/αα combining CD17/-28 (Hb: 46 g/L) were detected with history.@*CONCLUSIONS@#The detection rate of thalassemia genes is high and the mutations are diverse in the population of childbearing age in Chongzuo area of Guangxi. The common deletion genotype is --SEA/αα in α-thalassemia and CD41-42/N in β-thalassemia, and deletion genotype --Thai is not rare. There is a certain incidence of intermediate and severe β-thalassemia, and most patients require transfusion therapy. The results are beneficial for genetic consultation and intervention of thalassemia.