Smith-Lemli-Opitz Syndrome (SLOS) is a cholesterol metabolic disorder caused by deficiency of 7-dehydrocholesterol (7-DHC) reductase enzyme. Patients show prenatal and postnatal growth retardation, microcephaly, mental retardation, multiple major and minor anomaly symptoms. These anomalies include malfunctioning like distinctive facial dysmorphism, cleft palate, cardiac anomalies and postaxial polydactyly. The disease is autosomal recessive and brought about by mutations in DHCR7 gene.