Rare genetic disorder studied for clues to better care

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

* INCLUSION CRITERIA: * Any patient with biochemically confirmed SLOS will be accepted into this study. Patients of any age, either gender, or any ethnicity will be accepted into this study. No exclusions will be made based on race or gender. Historically, more males than females have been diagnosed as having SLOS. This bias was likely a result of the fact that genital hypoplasia is readily apparent in a male, and therefore the clinical diagnosis is easier to make in a male patient. SLOS syndrome appears more commonly in individuals of Northern European ancestry. Out of 150 biochemically proven cases, only one was an African American and no patients of Asian descent were reported. One SLOS mutant allele (R404C) appears to be present in individuals of French Canadian and Creole heritage. This likely represents a founder effect. One puzzling finding is that the carrier rate of the most common SLOS mutant allele in Black Canadians from Ontario and African Americans from Pennsylvania appears to be approximately 0.7%. However, clinical cases appear to be rare. The predominance of Caucasians reported in the literature may represent a bias of ascertainment of the disorder, variable presentation in different ethnic groups, or a founder effect in some ethnic groups. Because we function as a referral center with respect to recruitment, the ethnic background of our population is likely going to reflect the overall population of diagnosed cases. EXCLUSION CRITERIA: * Patients will be excluded if they cannot travel to the NIH because of their medical condition. * Pregnant women will be excluded, and a negative urine pregnancy test will be required of menstruating women. This protocol focuses on biosampling. Increasing blood draws during pregnancy for research is not appropriate. Fetuses will be excluded since the proposed evaluations are not possible during fetal life.