Department of Pediatrics, Seoul National University Hospital, Seoul, Korea.
Department of Pediatrics, Soonchunhyang University Hospital, Seoul, Korea.
J Korean Med Sci. 2020 Aug 17;35(32):e283. doi: 10.3346/jkms.2020.35.e283.
Renal tubular dysgenesis (RTD) is a rare fatal disorder in which there is poor development of proximal tubules, leading to oligohydramnios and the Potter sequences. RTD occurs secondary to renin-angiotensin system (RAS) blockade during the early stages of fetal development or due to autosomal recessive mutation of genes in the RAS pathway. A boy born at 33+1 weeks due to cord prolapse was found to be anuric and hypotensive. Pregnancy was complicated by severe oligohydramnios from gestational age 28+4 weeks. Abdominal sonography revealed diffuse globular enlargement of both kidneys with increased cortical parenchymal echogenicity. Infantogram showed a narrow thoracic cage and skull X-ray showed large fontanelles and wide sutures suggestive of ossification delay. Basal plasma renin activity was markedly elevated and angiotensin-converting enzyme was undetectable. Despite adequate use of medications, peritoneal dialysis, and respiratory support, he did not recover and expired on the 23rd day of life. At first, autosomal recessive polycystic kidney disease was suspected, but severe oligohydramnios along with refractory hypotension, anuria, skull ossification delay and high renin levels made RTD suspicious. gene analysis revealed compound heterozygous pathogenic variations of c.1454.dupC in exon 9 and c.2141dupA in exon 14, confirming RTD. Based on our findings, we propose that, although rare, RTD should be suspected in patients with severe oligohydramnios and refractory hypotension.
肾单位发育不良（RTD）是一种罕见的致命疾病，其近端小管发育不良，导致羊水过少和波特序列。RTD 继发于胎儿发育早期肾素-血管紧张素系统（RAS）阻断，或由于 RAS 途径中常染色体隐性基因突变。一名因脐带脱垂于 33+1 周出生的男婴出现无尿和低血压。妊娠从 28+4 孕周开始严重羊水过少而复杂化。腹部超声显示双侧肾脏弥漫性球形增大，皮质实质回声增强。婴儿胸片显示胸廓狭窄，颅骨 X 线显示前囟大且缝宽，提示骨化延迟。基础血浆肾素活性显著升高，血管紧张素转换酶不可检测。尽管充分使用药物、腹膜透析和呼吸支持，他仍未恢复，于出生后第 23 天死亡。起初怀疑常染色体隐性多囊肾病，但严重羊水过少伴难治性低血压、无尿、颅骨骨化延迟和高肾素水平使 RTD 可疑。基因分析显示外显子 9 中的 c.1454.dupC 和外显子 14 中的 c.2141dupA 复合杂合致病性变异，证实了 RTD 的诊断。根据我们的发现，我们提出尽管罕见，但对于严重羊水过少和难治性低血压的患者，应怀疑 RTD。
