SLOS is a metabolic disorder caused by a mutation in a gene that provides instructions for an enzyme  involved in the production of cholesterol. People who have SLOS are unable to make enough cholesterol to support normal growth and development. The effects, both physical and mental, range in severity among individuals. About 1 out of every 20,000-60,000 babies is born in the U.S. with SLOS. A child will only have symptoms if both parents are carriers of the gene mutation.

SLOS was formerly called RSH Syndrome. For more information and family support visit the Smith-Limli-Opitz Foundation or the National Organization for Rare Disorders (NORD).