The Genotypes Research On α-thalassimia In Zhanjiangn Area Guangdong Province

Objective:To analyze the genotypes ofα-thalassemia in Zhanjiang.Methods:Patients at Zhanjiang Maternal and Child Health Care Centre,the Affiliated Hospital of Guangdong Medical University,Maternal and Child Health Hospital of Xiashan District and Zhanjiang Second People’s Hospital from January 2017 to January 2018,were the cases in this study.The cases were analyzed by blood routine analysis,hemoglobin electrophoresis,gap-PCR,fluorescence quantitative PCR and DNA sequencing.The data were processed by SPSS 22.0 statistical software.Results:1.The genotypes of analysis:（1）586 cases were detected asα-thalassemia heterozygotes.Among 415 cases withα⁰-thalassemia,the genotypes included414 cases with--^SEA/ααand 1 case with--^Thai/αα.While in 171 cases withα⁺-thalassemia heterozygotes,their genotypes included 75 cases with-α^3.7/αα,54cases with-α^4.2/αα,26 cases withα^CSα/αα,9 cases withα^WSα/αα,and 7 cases withα^QSα/αα.（2）83 cases were detected as Hb H disease.Their genotypes included 51 cases with--^SEA/-α^3.7,22 cases with--^SEA/-α^4.2,7 cases with--^SEA/α^CSα,2 cases with--^SEA/α^{Poly A}αand 1 case with--^SEA/α^QSα.（3）3 cases were detected asα⁺-thalassemia homozygotes,their genotypes were the same as-α^3.7/-α^3.7.（4）9 cases were detected asα⁺-thalassemia double heterozygotes,their genotypes included 4 cases with-α^3.7/α^CSα,1 case with-α^3.7/-α^4.2,1 case with-α^4.2/α^CSα,1 case with-α^4.2/α^QSα,1 case with-α^4.2/α^WSαand 1 case withα^CSα/α^WSα.（5）There were 16 cases compounded withβ-thalassemia.The genotypes ofβ-thalassemia includedβ^CD41-42/β^N,β^-28/β^N,β^{IVS-II-654（C→T）}/β^N andβ^CD17/β^N.2.The results of blood analysis showed that RBC 1.1⁷.7×10¹²/L,Hb15.0¹78.0g/L,MCV 5.9¹61.7fL,MCH 13.0¹22.6pg,MCHC 22.3³69.0g/L,RDW 11.9³9.0%.The results of comparison of blood analysis were as follows:（1）Among 5 groups,α⁰-thalassemia heterozygotes group,α⁺-thalassemia heterozygotes group,α⁺-thalassemia homozygotes andα⁺-thalassemia double heterozygotes group,Hb H disease group,andα-thalassemia compounded withβ-thalassemia group,the values of Hb level,MCV and MCH value were the lowest in Hb H disease group,and RDW value was the highest in Hb H disease group.（2）MCV level inα^QSα/ααgenotype group was the lowest among non-deletionalα⁺-thalassemia heterozygotes groups.（3）For the sameα-thalassemia genotypes,MCV level in children anemia group was lower than those in adults anemia group.（4）Hb level in non-deletional Hb H disease was lower than those of deletional Hb H disease（P<0.05）.3.The results of Hb analysis were as follows:（1）The results of Hb analysis ofα-thalassemia heterozygotes showed that Hb A₂ 0.0⁶.0%.（2）The results of Hb analysis ofα⁺-thalassemia homozygotes showed that Hb A₂ 2.4².8%.（3）The results of Hb analysis ofα⁺-thalassemia double heterozygotes showed that Hb A₂ 1.5².5%.（4）The results of Hb analysis of Hb H disease showed that Hb A₂ 0.5².3%,Hb H 0.5²3.2%.（5）Hb H level in non-deletional Hb H disease was higher than those in deletional Hb H disease（P<0.05）.Conclusion:1.Alpha-thalassemia in Zhanjiang area included 19 genotypes,such as--^SEA/αα,--^Thai/αα,-α^3.7/αα,-α^4.2/αα,α^CSα/αα,α^WSα/αα,α^QSα/αα,-α^3.7/-α^3.7,-α^3.7/α^CSα,-α^3.7/-α^4.2,-α^4.2/α^CSα,-α^4.2/α^QSα,-α^4.2/α^WSα,α^CSα/α^WSα,--^SEA/-α^3.7,--^SEA/-α^4.2,--^SEA/α^CSα,--^SEA/α^{Poly A}α,--^SEA/α^QSα.The commonα-thalassemia in Zhanjiang area was deletional type.The most common genotype of deletionalα-thalassemia was--^SEA/αα,followed by-α^3.7/αα.The most common non-deletionalα-thalassemia wasα^CSα/αα.The common Hb H disease was deletional Hb H disease,in which the genotype of--^SEA/-α^3.7 was the most common form.2.The values of Hb level,MCV and MCH value were the lowest in Hb H disease group.RDW value was the highest in Hb H disease group.MCV level inα^QSα/ααgenotype group was the lowest among non-deletionalα⁺-thalassemia heterozygotes groups.For the sameα-thalassemia genotypes,MCV level in children anemia group was lower than those in adults anemia group.Comparing to the deletional Hb H disease,the anemia was more severe in non-deletional Hb H group.3.Hb H level in non-deletional Hb H disease was higher than those in deletional Hb H disease.4.--^SEA/α^{Poly A}αgenotype was first found in Guangdong province,which had intermediate anemia.Thailand deletionalα-thalassemia was first reported in Zhanjiang area.