CYP27A1 and Werner syndrome: Notable autosomal recessive forms of systemic cataract include; inborn errors affecting galactose metabolism (GALT, 9p; GALE,1p) and cholesterol biosynthesis (DHCR7, 11q; CYP27A1, 2q), the premature aging (progeroid) disorders, Werner syndrome (WRN, 8p) and Rothmund Thompson syndrome (RECQL4, 8q), and the spectrum of peroxisomal biogenesis disorders, which include Zellweger syndrome, neonatal adreno-leuko-dystrophy and rhizomelic chondroplasia punctata type-1 (1p, 1q, 6q, 7q, 12p, and 22q).