Toriumi Naohisa, Kaneda Makoto, Hatakeyama Naoki, Manabe Hiromi, Okajima Kazuki, Sakurai Yukari, Yamamoto Masayo, Sarashina Takeo, Ikuta Katsuya, Azuma Hiroshi
Department of Pediatrics, Asahikawa Medical University, 2-1, Midorigaoka-higashi, Asahikawa, 078-8510, Japan.
Sapporo Tokushukai Hospital, 1-1, Oyachi-higashi, Atsubetsu-ku, Sapporo, 004-0041, Japan.
Int J Hematol. 2018 Sep;108(3):339-343. doi: 10.1007/s12185-018-2435-1. Epub 2018 Apr 5.
A 10-year-old girl with persistent erythrocytosis and ruddy complexion was diagnosed with primary familial congenital polycythemia (PFCP) involving a novel heterozygous mutation of c.1220C>A, p.Ser407X in exon 8 of the erythropoietin receptor gene (EPOR). This mutation causes truncation of EPOR, resulting in loss of the cytoplasmic region, which is necessary for negative regulation of erythropoietin signal transmission. Genetic analysis showed that the mutated EPOR was inherited from her mother. Her mother had polycythemia and had undergone venesection several times when she was young, but her polycythemic state appeared to have resolved. Venesection was not needed to maintain Hct levels within normal range. For the case reported here, venesection was also conducted to maintain the blood Hct level below 50%. We observed that after the patient experienced menarche, the volume and frequency of venesection needed to maintain Hct level < 50% were clearly reduced compared with those before menarche. These findings suggest that, in female patients with this type of EPOR mutation, menstruation might reduce blood volume in a manner similar to venesection. Spontaneous remission of erythrocytosis may thus occur after the start of menstrual bleeding.
一名10岁女孩，持续性红细胞增多且面色红润，被诊断为原发性家族性先天性红细胞增多症（PFCP），其促红细胞生成素受体基因（EPOR）第8外显子存在一种新的杂合突变c.1220C>A，p.Ser407X。这种突变导致EPOR截短，致使胞质区域缺失，而该区域对于促红细胞生成素信号传导的负调控是必需的。基因分析表明，突变的EPOR是从她母亲那里遗传而来。她的母亲曾患有红细胞增多症，年轻时接受过多次放血治疗，但她的红细胞增多状态似乎已得到缓解。无需进行放血就能将血细胞比容水平维持在正常范围内。对于此处报道的病例，也进行了放血治疗以将血液血细胞比容水平维持在50%以下。我们观察到，该患者初潮后，与初潮前相比，维持血细胞比容水平<50%所需的放血次数和量明显减少。这些发现表明，对于患有这种类型EPOR突变的女性患者，月经可能以类似于放血的方式减少血容量。因此，月经出血开始后红细胞增多症可能会自发缓解。
