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)