[Autosomal recessive renal tubular dysgenesis: morphologic and genetic study of 2 cases]

Renal tubular dysgenesis (RTD) is a rare and severe nephropathy characterized by persistent fetal anuria leading to oligohydramnios with the Potter sequence, and perinatal death. The diagnosis is based on the histological finding of absence or paucity of proximal tubules. A consanguineous family is described in which 2 siblings, born after pregnancies complicated by oligohydramnios were affected with RTD. Patients were small for gestational age at birth. The first patient died after a few hours, the second after a few days of life, with persistent anuria unresponsive to treatment. Histologically, there was marked reduction in the number of proximal tubule sections and no renin was detected by immunohistochemistry. An homozygous mutation of the gene encoding renin was identified in both patients. This study underlines the interest of the histological examination of the kidney for the diagnostic of RTD in anuric fetuses and newborns, and the possibility of mutation analysis of RAS genes for genetic counselling and early prenatal diagnosis.