Kidneys in Meckel's syndrome as a model of abnormal renal differentiation

Kidneys of nine human fetuses of 16-22 weeks of gestational age with Meckel's syndrome were studied. All kidneys were grossly enlarged and cystic. The morphological picture is appreciably different form the kidneys of full term infants with the same syndrome. All kidneys showed distinct subcapsular nephrogenic zone from which the cysts arise. The cyst wall retains characteristics that recall its origins from preformed nephrons and collecting ducts, as can be demonstrated histologically and with lectin and antibody markers. Studies on abnormal fetal kidneys when combined with segment-specific molecular markers of the nephron are invaluable in unraveling the pathogenesis of the various types of human cystic renal diseases.