Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Int J Hematol. 2024 Aug;120(2):179-185. doi: 10.1007/s12185-024-03796-y. Epub 2024 May 27.
Congenital antithrombin (AT) or serpin C1 deficiency, caused by a SERPINC1 abnormality, is a high-risk factor for venous thrombosis. SERPINC1 is prone to genetic rearrangement, because it contains numerous Alu elements. In this study, a Japanese patient who developed deep vein thrombosis during pregnancy and exhibited low AT activity underwent SERPINC1 gene analysis using routine methods: long-range polymerase chain reaction (PCR) and real-time PCR. Sequencing using long-range PCR products revealed no pathological variants in SERPINC1 exons or exon-intron junctions, and all the identified variants were homozygous, suggesting a deletion in one SERPINC1 allele. Copy number quantification for each SERPINC1 exon using real-time PCR revealed half the number of exon 1 and 2 copies compared with controls. Moreover, a deletion region was deduced by quantifying the 5'-upstream region copy number of SERPINC1 for each constant region. Direct long-range PCR sequencing with primers for the 5'-end of each presumed deletion region revealed a large Alu-mediated deletion (∼13 kb) involving SERPINC1 exons 1 and 2. Thus, a large deletion was identified in SERPINC1 using conventional PCR methods.
先天性抗凝血酶（AT）或丝氨酸蛋白酶抑制剂 C1 缺乏症（由 SERPINC1 异常引起）是静脉血栓形成的高危因素。SERPINC1 容易发生基因重排，因为它包含许多 Alu 元件。在这项研究中，一名在怀孕期间发生深静脉血栓形成且 AT 活性较低的日本患者使用常规方法进行了 SERPINC1 基因分析：长距离聚合酶链反应（PCR）和实时 PCR。使用长距离 PCR 产物进行测序未发现 SERPINC1 外显子或外显子-内含子接头的病理性变异，并且所有鉴定的变异均为纯合子，提示一个 SERPINC1 等位基因缺失。使用实时 PCR 对每个 SERPINC1 外显子进行拷贝数定量显示与对照组相比，外显子 1 和 2 的拷贝数减少了一半。此外，通过定量 SERPINC1 每个恒定区的 5'-上游区域拷贝数来推断缺失区域。用针对每个假定缺失区域 5'末端的引物进行直接长距离 PCR 测序显示涉及 SERPINC1 外显子 1 和 2 的较大 Alu 介导缺失（约 13 kb）。因此，使用常规 PCR 方法在 SERPINC1 中鉴定出了一个大的缺失。
