Our study population includes patients of all ages and ethnic groups, and both genders. The inclusion of children is essential to a research study that is correlating genotype with phenotype, and is attempting an early identification of metabolic abnormalities that may be best treated at an early age. Many of the age-dependent manifestations of BBS develop during childhood and the average age of diagnosis is 9.2 years. Pregnant women and children under the age of 5 yr do not undergo invasive research procedures (i.e. phlebotomy) or procedures involving ionizing radiation (i.e. X-rays or DEXA scans) unless that procedure would be performed as part of standard medical care.