Familial nature of congenital absence and severe dysgenesis of both kidneys.

Seventy-one parents and 40 siblings of 41 index patients with bilateral renal agenesis, bilateral severe dysgenesis, or agenesis of one kidney and dysgenesis of the other were evaluated by gray-scale ultrasonography for genitourinary malformations. Nine per cent (10 of 111) had asymptomatic renal malformations, most often unilateral renal agenesis (4.5 per cent--a frequency that was significantly higher than the frequency of 0.3 per cent among 682 adults [P less than 0.004]). We recommend ultrasonographic screening for parents and siblings of infants born with agenesis or dysgenesis of both kidneys or with agenesis of one kidney and dysgenesis of the other, since renal malformations may have medical implications even for asymptomatic patients.