The first patient, a 10-year-old girl, presented with pancytopenia and recurrent epistaxis, along with a history of repeated upper respiratory infections, café-au-lait spots, and microcephaly. Genetic testing revealed compound heterozygous mutations in the DNA ligase IV (LIG4) gene, leading to a diagnosis of LIG4 syndrome. The second patient, a 6-year-old girl, was seen for persistent thrombocytopenia lasting over two years and was noted to have short stature, hyperpigmented skin, and hand malformations. She had a positive result from chromosome breakage test. She was diagnosed with Fanconi anemia complementation group A. Despite similar clinical presentations, the two children were diagnosed with different disorders, suggesting that children with hemocytopenia and malformations should not only be evaluated for hematological diseases but also be screened for other potential underlying conditions such as immune system disorders.
患儿1，女，10岁，因全血细胞减少伴反复鼻衄就诊，有反复上呼吸道感染史，有皮肤咖啡斑、小头畸形，基因检测发现DNA连接酶IV（ligase IV, LIG4）基因存在复合杂合变异，诊断为LIG4综合征。患儿2，女，6岁，因血小板减少2年余就诊，有身材矮小、皮肤黝黑、手部畸形等，染色体断裂试验检查结果为阳性，诊断为范可尼贫血互补组A型。该2例患儿临床表现相似，最终诊断为两类疾病，提示血细胞减少伴畸形的患儿并非仅是血液病，需警惕免疫系统等其他疾病。.
Keywords: Child; Cytopenia; Fanconi anemia; LIG4 syndrome; Malformation.