Angiographic findings in the kidney in the Laurence-Moon-Biedl syndrome

Cystic kidney dysplasia and polydactyly in 3 sibs with Bardet-Biedl syndrome

Two infants with cystic kidney dysplasia and polydactyly were born to consanguineous parents. One infant died at age 2 months, and the other is currently 3.5 years old. A third pregnancy was terminated following ultrasonographic visualization of large echo-dense fetal kidneys and polydactyly. Although none had apparent brain anomalies, they were considered to represent the Meckel syndrome. Extinguished responses on electroretinography in our 3.5-year-old patient has led to the diagnosis of Bardet-Biedl syndrome. This observation offers an opportunity to revisit the Bardet-Biedl syndrome and provides further evidence that structural renal abnormalities are characteristic of the syndrome. We wish to alert the clinician to the diagnosis of Bardet-Biedl syndrome in patients with infantile cystic kidney dysplasia.

The spectrum of renal disease in Laurence-Moon-Biedl syndrome

To determine the nature, extent, and severity of renal involvement in Laurence-Moon-Biedl syndrome (obesity, mental retardation, polydactyly, hypogonadism, and pigmented retinal dystrophy), we evaluated 20 of 30 patients with the disorder identified from ophthalmologic records in Newfoundland. The mean age was 31 years, and seven were male. All 20 patients had structural or functional abnormalities of the kidneys or both. Three had end-stage renal disease, with two requiring maintenance hemodialysis. The remaining 17 patients had normal serum creatinine values and estimated creatinine clearances. Half the subjects had hypertension. Fourteen of 17 patients could not concentrate urine above 750 mOsm per kilogram of body weight even after vasopressin, whereas all 10 normal controls could. Urinary pH decreased below 5.3 after ammonium chloride administration in all 15 normal controls, but in only 13 of 18 patients. Calyceal clubbing or blunting was evident in 18 of 19 patients studied by intravenous pyelography; 13 patients had calyceal cysts or diverticula. Seventeen of 19 patients had lobulated renal outlines of the fetal type. Four patients had diffuse renal cortical loss, but only two of these had renal insufficiency. We conclude that Laurence-Moon-Biedl syndrome includes the presence of renal abnormalities.