(John Zachariah Laurence, 18301874, British ophthalmologist, Robert C. Moon, 18441914, American ophthalmologist, Artur Biedl, 18691933, Austrian physician), autosomal recessive condition the features of which are mental retardation, hypogonadism, pigmented retinopathy and renal tract abnormalities, the dominant features of which are renal cysts and renal hypoplasia. The kidneys are usually somewhat enlarged and on ultrasound appear echo bright. Function is often reduced. The differential diagnosis of the renal appearances include infantile polycystic kidney disease but other features such as polydactyly usually enable this condition to be differentiated.