Novel germline <i>SAMD9</i> mutation in an elderly patient with myelodysplastic syndrome
Novel germline <i>SAMD9</i> mutation in an elderly patient with myelodysplastic syndrome
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老年骨髓增生异常综合征患者的新种系 <i>SAMD9</i> 突变
DOI：
10.11406/rinketsu.63.865
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
萩原 政夫
中科院分区：
文献类型：
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作者：
内田 智之;藤井 高幸;大原 慎;今井 唯;井上 盛浩;原田 結花;原田 浩徳;萩原 政夫
一名80岁的日本男性患者因疲劳就诊于我院。他的外周血检查显示全血细胞减少，以淋巴细胞为主，但没有原始细胞。由于干抽，骨髓（BM）抽吸失败，随后的 BM 活检显示骨髓细胞减少并伴有纤维化。根据 CD34 阳性细胞，他被诊断患有骨髓增生异常综合征 (MDS)，并伴有原始细胞过多 (EB)-2。 BM 的染色体分析显示为 7 号单体，并使用新一代测序检测到 SAMD9 W22* 突变（变异等位基因频率 [VAF] 为 51.22%）。在颊粘膜中观察到相同的突变（VAF为50%），这被证实为种系突变。据报道，SAMD9 基因突变是 MIRAGE 综合征和儿童型 MDS 的致病基因之一。本病例被认为是由于接近全长 SAMD9 缺失而导致的功能丧失突变。这是首例以 SAMD9 W22* 为种系突变的 MDS 成人病例。
An 80-year-old Japanese male patient presented to our hospital with complaints of fatigue. His peripheral blood tests revealed pancytopenia with predominant lymphocytes and without blasts. The bone marrow (BM) aspiration was unsuccessful due to a dry tap, and the subsequent BM biopsy revealed hypocellular marrow with fibrosis. He was diagnosed with myelodysplastic syndrome (MDS) with excess blasts (EB)-2 based on CD34-positive cells. The chromosome analysis of the BM revealed monosomy 7, and the SAMD9 W22* mutation was detected (variant allele frequency [VAF] of 51.22%) using next-generation sequencing. An identical mutation was observed in the buccal mucosa (VAF of 50%), which was confirmed as a germline mutation. The SAMD9 gene mutation is reported as one of the causative genes for MIRAGE syndrome and child-onset MDS. The present case was considered a loss-of-function mutation due to the near full-length SAMD9 deletion. This is the first adult case of MDS with SAMD9 W22* as a germline mutation.