Colombo North Teaching Hospital, Ragama, Sri Lanka.
Department of Paediatrics, Faculty of Medicine, University of Kelaniya, Thalagolla Road, Ragama, 11010, Sri Lanka.
BMC Pediatr. 2023 Aug 1;23(1):382. doi: 10.1186/s12887-023-04207-7.
Lysinuric protein intolerance is a rare inherited metabolic disease due to autosomal recessive mutations of the SLC7A7 gene. The affected patients commonly present with protein-rich food intolerance, failure to thrive, hepatosplenomegaly, muscle hypotonia and lung involvement due to impaired intestinal absorption and excessive urinary excretion of dibasic amino acids. Presentation with splenomegaly and cytopenia without other features has not been reported. Here we report a Sri Lankan girl with lysinuric protein intolerance presenting with pancytopenia and splenomegaly mimicking acute leukaemia.
Two years and six months old Sri Lankan girl presented with persistent pancytopenia following a viral illness. She was asymptomatic without vomiting, diarrhoea, abdominal pain or irritability. Physical examination revealed pallor and isolated firm splenomegaly of 2 cm. Growth parameters and other system examinations were normal. Full blood count revealed anaemia, leukopenia and thrombocytopenia. The blood picture showed a mixture of hypochromic microcytic and normochromic normocytic red cells with occasional pencil cells and macrocytes. Bone marrow examination was normal except for occasional megaloblasts; however, serum vitamin B12 and red blood cell folate were normal. The metabolic screen showed a high anion gap compensated metabolic acidosis, high lactate and ketosis. Genetic mutation analysis using whole exome sequencing revealed compound heterozygous variants of the SLC7A7 gene, confirming the diagnosis of lysinuric protein intolerance.
We report a child with lysinuric protein intolerance presenting with pancytopenia and splenomegaly without other disease features. This case report adds to the heterogenic presentations of lysinuric protein intolerance, which is considered a multifaceted disease.
赖氨酸尿蛋白不耐受症是一种罕见的遗传性代谢疾病，由 SLC7A7 基因突变引起，呈常染色体隐性遗传。受影响的患者通常表现为高蛋白食物不耐受、生长不良、肝脾肿大、肌肉张力减退和肺部受累，这是由于肠道吸收受损和二碱基氨基酸过度尿排泄所致。目前尚未报道表现为脾肿大和细胞减少症而无其他特征的病例。本文报告了一例斯里兰卡女孩，患有赖氨酸尿蛋白不耐受症，表现为全血细胞减少和脾肿大，类似于急性白血病。
一名 2 岁零 6 个月大的斯里兰卡女孩在病毒性疾病后持续出现全血细胞减少。她无症状，无呕吐、腹泻、腹痛或烦躁不安。体格检查显示苍白和孤立性脾肿大 2cm。生长参数和其他系统检查均正常。全血细胞计数显示贫血、白细胞减少和血小板减少。血象显示小细胞低色素和正细胞正色素红细胞混合存在，偶尔有铅笔细胞和巨红细胞。骨髓检查除偶尔出现巨幼细胞外正常；然而，血清维生素 B12 和红细胞叶酸正常。代谢筛查显示阴离子间隙增高的代偿性代谢性酸中毒、高乳酸和酮症。全外显子组测序的基因突变分析显示 SLC7A7 基因的复合杂合变异，证实了赖氨酸尿蛋白不耐受症的诊断。
我们报告了一例赖氨酸尿蛋白不耐受症患儿，表现为全血细胞减少和脾肿大，无其他疾病特征。本病例报告增加了赖氨酸尿蛋白不耐受症的异质性表现，该疾病被认为是一种多方面的疾病。
