Marble brain disease: recessive osteopetrosis, renal tubular acidosis and cerebral calcification in three Saudi Arabian families.

Four children are described from three Saudi Arabian families suffering from osteopetrosis, distal renal tubular acidosis and cerebral calcification associated clinically with mental retardation, stunted growth, abnormal teeth and a similar facial appearance. The syndrome is inherited as an autosomal recessive. The growth retardation is attributed to renal tubular acidosis but no metabolic link is evident between its other major features, and the fundamental defect is unknown. The disorder is radiologically indistinguishable from the classical recessive (malignant) and dominant (benign) forms of osteopetrosis but its other characteristics establish it as a separate disease entity.