Sterol and Isoprenoid Disease Research Consortium: Smith-Lemli-Opitz Syndrome

The purpose of this study is to learn about Smith-Lemli-Opitz Syndrome (SLOS). SLOS is an inherited condition that is caused by the body not making an enzyme as it should. The body needs the enzyme to help make cholesterol. SLOS can cause many health problems including slow growth and development, eating disorders, sleep disorders, behavior disorders, and eye diseases. Severe SLOS leads to birth defects and mental retardation and in many cases early death. The investigators plan to measure cholesterol and other sterol levels, perform clinical observations, whole body testing and imaging (brain MRIs), to learn more about the disease and its progression, differences in the clinical features among individuals with SLOS, and look at the effect of cholesterol supplementation in this condition. The study is an interventional study to characterize disease progression and correlations between clinical, biochemical and physiological features of the disease. The main hypothesis is that dietary cholesterol supplementation does not improve features of SLOS related to the brain (e.g. IQ, behavior).