A boy aged 2 months (born at 36 weeks of gestation) was admitted due to cough and dyspnea. After admission, he was found to have persistent hypertension, proteinuria, and persistent convulsion, and imaging examination showed extensive calcification of the aorta and major branches and stenosis of local lumens of the abdominal aorta and the right renal artery with increased blood flow velocity. The boy was admitted during the neonatal period due to wet lung and pulmonary arterial hypertension and was found to have hypertension and proteinuria. High-throughput whole-exome sequencing was performed and found two compound heterozygous mutations in the ENPP1 gene from his parents, c.130C>T (p.Q44X) and c.1112A>T (p.Y371F). c.130C>T was a nonsense mutation, which could cause partial deletion of protein from 44 amino acids, and was defined as a primary pathogenic mutation. c.1112A>T was a missense mutation which had been reported as a pathogenic mutation associated with idiopathic infantile arterial calcification (IIAC). Therefore, he was diagnosed with IIAC. He was given phosphonate drugs, antihypertensive drugs, anticonvulsion treatment, and respiratory support. Blood pressure was maintained at the upper limit of normal value. There was no deterioration of arterial calcification. It is concluded that IIAC should be considered for infants with persistent hypertension and extensive vascular calcification, and imaging and genetic examinations should be performed as early as possible to make a confirmed diagnosis.
患儿（36周胎龄出生），男，2个月，因咳嗽、呼吸困难入院。入院后发现患儿存在持续性高血压、蛋白尿和惊厥持续状态，影像学提示主动脉及大分支广泛钙化，腹主动脉、右肾动脉局部管腔变窄伴血流速度增快。患儿新生儿期因湿肺、肺动脉高压住院，期间曾发现高血压、蛋白尿。进一步行全外显子组基因高通量测序，发现患儿ENPP1基因存在源自父母的复合杂合突变：c.130C > T（p.Q44X）和.c.1112A > T（p.Y371F）。c.130C > T为无义突变，可造成蛋白质从44个氨基酸之后的部分缺失，为一级致病性突变形式；c.1112A > T为错义突变，为已报道的与特发性婴儿动脉钙化症（ⅡAC）相关的致病性突变。因此确诊为ⅡAC。给予膦酸盐及降压、止惊、呼吸支持等对症治疗，血压维持在正常高限，动脉钙化未恶化。对于持续高血压伴广泛大血管钙化的小婴儿，应注意ⅡAC的可能，尽早行影像学及基因检查确诊。