Study of Inborn Errors of Cholesterol Synthesis and Related Disorders

This study will investigate the cause and medical problems associated with a group of genetic disorders known as inborn errors of cholesterol synthesis, in which the body does not produce cholesterol. People with this disorder may have birth defects and learning and behavioral problems. People with an inborn error of cholesterol synthesis and related disorders, including Smith-Lemli-Opitz syndrome, lathosterolosis, desmosterolosis, X-linked dominant chondrodysplasia, CHILD syndrome, Greenberg dysplasia, and some cases of Antley-Bixler syndrome, may be eligible for this study. People who are carriers of the disorders also may enroll. Participants and family members will provide blood and urine samples, as well as other tissue samples collected during medically indicated procedures such as biopsy or surgery. These tissues may include, for example, gallstones, cataracts, cerebrospinal fluid, amniotic fluid, lymph tissue, and DNA samples. In rare instances, a skin biopsy may be requested to aid in establishing a diagnosis. Medical information will also be gathered from medical records, photographs, and X-rays.

It is known that inborn errors of cholesterol synthesis give rise to human malformation/cognitive impairment syndromes. Smith-Lemli-Opitz syndrome is the prototypical example of a post-squalene inborn error of metabolism; however, this group of disorders now includes lathosterolosis, desmosterolosis, X-linked dominant chondrodysplasia (CDPX2), CHILD syndrome, HEM dysplasia, and some cases of Antley-Bixler syndrome (1-3). Due to the extremely rare occurrence of some of these disorders, the full phenotypic spectrum has yet to be defined. Cholesterol transport in cells can also cause a disorder known as Niemann-Pick Disease type C (NPC). NPC belongs to a group of disorders known as lysosomal storage disorders. The purpose of this protocol is to 1) allow for the collection of biomaterial and medical information that can be studied to gain insight into the pathological processes; 2) allow for the collection of DNA and medical information from individuals who have a phenotypic resemblance to known disorders of cholesterol synthesis, lysosomal storage disorders or individuals who may be carriers of these disorders.