The complete absence of one (unilateral) or both (bilateral) kidneys. Agenesis means "without a beginning". Also known as Potter's Syndrome, bilateral renal agenesis is the complete absence of both kidneys. Severe oligohydramnios (too little amniotic fluid) results, causing growth retardation, typical 'Potter's facies' (beak-like nose, receding chin, and large, low-set ears), and pulmonary hypoplasia (failure of the lungs to reach full size). This condition is incompatible with life.