联合X-连锁基因多个多态性位点采用逆转录检测法进行造血细胞克隆性分析

Determination of hematopoietic clonality by detection of multiple X-linked gene exonic polymorphic lo- ci using transcription-based clonality assays

目的探索中国正常女性X-连锁葡萄糖6-磷酸脱氢酶（G6PD）、P55、BTK、FHL-1基因外显子多态性位点的杂合子基因型频率，并探讨应用以上位点采用基于X染色体失活克隆性检测法-逆转录检测法进行造血细胞克隆性分析的价值。方法采集446名中国正常女性外周血标本，提取基因组DNA，应用等位基因特异性PCR或PCR-限制性片段长度多态性方法分析X-连锁G6PD、P55、BTK、FHL·1基因外显子多态性位点的杂合基因型频率。以上述杂合位点作为克隆性分析的标记，采用逆转录检测法分析有JAK2V617F突变或克隆性染色体异常的原发性血小板增多症（ET）女性患者造血细胞的克隆性。结果446名中国正常女性G6PD基因杂合基因型频率为12．8％（57例），P55基因杂合基因型频率为29．4％（131例），BTK基因杂合基因型频率为52．0％（232例），FHL-1基因杂合基因型频率为46．4％（207例）。4个多态性位点中具有至少1个杂合位点的正常女性占81．4％（363例）。对G6PD、P55、BTK或FHL-1为杂合子且伴JAK2V617F突变的10例ET患者，应用逆转录检测法进行造血细胞克隆性分析，所有患者均为单克隆／寡克隆。结论基于X染色体失活的克隆性检测法-逆转录检测法可用于约80％中国女性患者的克隆性分析。

Objective To explore the frequencies of heterozygosity in X-linked G6PD, P55, BTK, and FHL-1 gene exonic polymorphic loci among Chinese females and the value of determination of hematopoietic clonality by detection of these X-chromosome exonic polymorphisms based on X-chromosome inactivation patterns （XCIP）-transcription-based clonality assays （TCA）. Methods Genomic DNA was extracted from peripheral blood of 446 Chinese healthy females. Allele-specific PCR （ASPCR） or PCR-restrietion enzyme digestion method was applied for detecting G6PD, 1955, BTK and FHL-1 polymorphisms. Those heterozygotic loci were used as markers to examine the hematopoietic clonality of bone marrow mononuelear cells by TCA from essential thrombocythemia （ET） patients with （MDS） patients with abnormal karyotype. Results JAK2V617F mutation and myelodysplastic syndrome Among the total 446 genomic DNA samples, the frequencies of heterozygosity in G6PD, P55, BTK and FHL-1 loci were 12.8% , 29.4% , 52.0% and 46.4%, respectively. About 81.4% of females were heterozygous at one or more loci. All 10 ET patients with JAK2V617F mutation and 2 MDS patients with abnormal karyotype, which were heterozygotic in either locus, had monoclonal/oligoclonal hematopoiesis. Conclusion Clonality detection based on X chromosome inactivation patterns - transcription based clonality assays is applicable to about 80% of Chinese females.