At least three cases of the Meckel syndrome have been identified in the Hutterites. Two of these were sibs and were studied during life; the other, a close relative, was diagnosed retrospectively by a review of hospital records. All parents were consanguineous. The phenotype ranged in severity from the association of occipital meningocele, cystic kidneys, postaxial polydactyly, and microphthalmia to a milder expression consisting of cystic kidneys, ocular defects apparent only on funduscopic examination, and a brain abnormality demonstrated by computer tomography. Survival ranged from 5 to 13 months. In one patient, the renal lesion was manifested as a tubular rather than a glomerular defect, and was probably not the primary cause of death.