Departments of Pediatrics.
Pathology.
J Pediatr Hematol Oncol. 2022 Mar 1;44(2):e444-e446. doi: 10.1097/MPH.0000000000002213.
Imerslund-Gräsbeck syndrome is an autosomal recessive disorder of vitamin B12 malabsorption presenting with megaloblastic anemia and mild proteinuria in childhood. The disorder is caused by biallelic pathogenic variants in the CUBN or AMN genes, which encode proteins involved in B12 absorption. We present the case of a 17-month-old boy with failure to thrive, pancytopenia, and fevers. His megaloblastic anemia was overlooked leading to unnecessary invasive testing. Findings on bone marrow biopsy prompted investigation for genetic disorders of B12 metabolism. Exome sequencing uncovered 1 known pathogenic variant and 1 novel likely pathogenic variant in CUBN, confirming the diagnosis of Imerslund-Gräsbeck syndrome.
艾姆斯勒-格鲁斯贝克综合征是一种常染色体隐性遗传疾病，维生素 B12 吸收不良，表现为儿童期巨幼细胞性贫血和轻度蛋白尿。该疾病由 CUBN 或 AMN 基因中的双等位基因致病性变异引起，这些基因编码参与 B12 吸收的蛋白质。我们报告了一例 17 个月大的男孩，表现为生长不良、全血细胞减少和发热。他的巨幼细胞性贫血被忽视，导致不必要的侵入性检查。骨髓活检结果提示存在 B12 代谢遗传疾病。外显子组测序发现 CUBN 中有 1 个已知致病性变异和 1 个新的可能致病性变异，从而确诊艾姆斯勒-格鲁斯贝克综合征。
