A sex-linked recessive disorder affecting multiple systems including the EYE, the NERVOUS SYSTEM, and the KIDNEY. Clinical features include congenital CATARACT; MENTAL RETARDATION; and renal tubular dysfunction (FANCONI SYNDROME; RENAL TUBULAR ACIDOSIS; X-LINKED HYPOPHOSPHATEMIA or vitamin-D-resistant rickets) and SCOLIOSIS. This condition is due to a deficiency of phosphatidylinositol 4,5-bisphosphate-5-phosphatase leading to defects in PHOSPHATIDYLINOSITOL metabolism and INOSITOL signaling pathway. (from Menkes, Textbook of Child Neurology, 5th ed, p60; Am J Hum Genet 1997 Jun;60(6):1384-8).