Division of Hematology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.
Int J Hematol. 2021 May;113(5):760-764. doi: 10.1007/s12185-020-03068-5. Epub 2021 Jan 2.
Congenital thrombotic thrombocytopenic purpura (cTTP) is a rare disease that is defined as biallelic mutations of ADAMTS13 causing persistent absence of ADAMTS13 activity. The confirmed diagnosis requires a genetic study, and cTTP has never been previously reported in Taiwan. Our patient was a 29-year-old Taiwanese woman who presented with severe hyperbilirubinemia at birth. She had severe thrombocytopenia and hemolytic anemia at the age of 1, and another acute TTP event at the age of 7 triggered by an upper airway infection. Regular plasma replacement was started at age 12 based on a presumptive diagnosis of cTTP. Clinical diagnosis of cTTP, with undetectable ADAMTS13 activity and absence of ADAMTS13 inhibitor, was confirmed at age 27. A genetic study showed a previously reported mutation c.1921G to A, inherited from her father, and a maternally inherited, novel mutation at exon 12, c.1435+1dupG, which results in a splicing site change and frame shift. Reports of cTTP from East Asia, except Japan, are scarce. Some prevalent ADAMTS13 mutations are also race or region specific. With this report, we hope to raise awareness among physicians in Taiwan, promote early, proper diagnosis of cTTP, and reveal the true prevalence of cTTP in the Taiwanese population.
先天性血栓性血小板减少性紫癜（cTTP）是一种罕见的疾病，其定义为 ADAMTS13 的双等位基因突变导致 ADAMTS13 活性持续缺失。确诊需要进行基因研究，而 cTTP 在台湾从未有过报道。我们的患者是一位 29 岁的台湾女性，出生时即出现严重高胆红素血症。她在 1 岁时出现严重血小板减少和溶血性贫血，7 岁时因上呼吸道感染而再次发生急性 TTP。根据 cTTP 的初步诊断，她从 12 岁开始定期接受血浆置换治疗。27 岁时，根据临床表现和 ADAMTS13 活性检测及 ADAMTS13 抑制物检测结果，确诊为 cTTP。基因研究显示，她携带了一个从父亲那里遗传而来的先前报道的突变 c.1921G to A，以及一个从母亲那里遗传而来的、位于 12 号外显子的新突变 c.1435+1dupG，该突变导致剪接位点改变和移码。除日本外，东亚地区关于 cTTP 的报道很少。一些常见的 ADAMTS13 突变也具有种族或地区特异性。通过本报告，我们希望提高台湾医生对此病的认识，促进 cTTP 的早期、正确诊断，并揭示 cTTP 在台湾人群中的真实患病率。
