Objective: To analyze the molecular polymorphisms of CD36 among 58 blood donors with CD36 deficiency and compare with CD36 positive controls.
Methods: A total of 58 donors with CD36 deficiency during a screening conducted in the laboratory from September 2019 to December 2020 were enrolled as the test group, including 39 males and 19 females, while 120 platelet donors with CD36 positive were randomly selected as the controls, including 76 males and 44 females. All of the subjects were Han nationality. The PCR-SBT method was used to detect coding region of CD36 gene, and molecular mutations were compared with those CD36 positive controls.
Results: Among the 58 donors with CD36 deficiency, mutations appears in 32 individuals. The detection rate for type I was 71.43% (5/7), and type II was 51.92% (27/52), while among the 120 controls, mutations appears in 12 donors (10%). In the CD36 antigen-deficient donors, 16 variations were found, in which 329-330 del AC with the highest frequency accounted for 20.69%, followed by 1228-1239 del ATTGTGCCTATT(15.52%) and 1156 C>T(10.34%). Two variations, 198-205 del GATCTTTG and 220 C>T, led to premature termination of translation; four mutations, 329-330 del AC, 560 ins T, 1011-1049 39bp dupl and 1343-1344 ins TCTT, caused translation frame shift; 1228-1239 del ATTGTGCCTATT led to deletion of four amino acids (Ile-Val-Pro-Ile) at sites 410-413 of the peptide chain. The 1140 T>A and 1275 G>A were synonymous mutations, and the other 7 mutations resulted in the substitution of single nucleotide. The platelet expression in the donors of CD36 positive with 329-330 del AC or 1228-1239 del ATTGTGCCTATT mutation (heterozygote) was lower than those CD36 positive individuals without mutations (homozygote).
Conclusion: Multiple gene mutations in the CD36 coding region may cause CD36 deficiency, and the heterozygous individuals with mutations may lead to CD36 antigen reduction or deletion. Mutation is not detected in 44.83% of CD36 deficient individuals, there may be some other reasons for the CD36 antigen deficiency.
题目: 深圳地区血小板捐献者CD36抗原缺失型的基因多态性研究.
目的: 分析58名CD36抗原缺失型血小板捐献者的CD36基因分子变异情况.
方法: 选取2019年9月至2020年12月本实验室筛查到的58名CD36抗原缺失型献血者，并将其作为研究组，其中男性39名，女性19名，均为汉族。另随机挑选2020年12月深圳市血液中心血小板无偿献血者120名，其中男性76名，女性44名，均为汉族，经流式细胞术检测CD36抗原阳性者作为对照组。采用PCR-SBT检测所有样本CD36基因的编码区，分析献血者CD36抗原缺失型的基因突变情况，并与抗原阳性对照者的基因突变类型进行比较.
结果: 58名CD36抗原缺失型献血者中，有32名检测出CD36基因突变，Ⅰ型71.43%（5/7），Ⅱ型52.94%（27/51）。120名CD36抗原阳性对照者中有12名检测出CD36基因突变，突变个体比例为10%。在CD36抗原缺失型献血者中发现16种基因突变，发生突变频率最高的为329-330 del AC（20.69%），其次为1228-1239 del ATTGTGCCTATT（15.52%）和1156 C>T（10.34%）。198-205 del GATCTTTG和220 C>T这2种突变导致翻译提前终止，329-330 del AC、560 ins T、1011-1049 39bp dupl和1343-1344 ins TCTT这4种突变导致翻译移码，1228-1239 del ATTGTGCCTATT导致肽链第410-413位缺失Ile-Val-Pro-Ile 4个氨基酸，1140 T>A和1275 G>A这2种为同义突变，其余7种突变均导致肽链上单个核苷酸的替换。CD36抗原阳性对照组中存在329-330 del AC和1228-1239 del ATTGTGCCTATT基因突变的杂合子献血者，其血小板CD36表达量低于抗原阳性野生型组的平均水平.
结论: CD36基因编码区的多种基因突变可能引起CD36抗原缺失，含突变的杂合子可能导致CD36抗原表达降低或者缺失，44.83%的抗原缺失型CD36基因编码区未检测出突变，存在其他原因引起CD36抗原缺失.
Keywords: CD36; platelet; polymorphism.