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Smith-Lemli-Opitz Syndrome (SLOS) Research The Smith-Lemli-Opitz Syndrome Research Program was created with the goal of characterizing the behavioral phenotype of the disorder as well as improving the currently available treatment. The program includes neurobehavioral studies of Smith-Lemli-Opitz syndrome and a clinical trial of Simvastatin. Faculty involved in the program are investigators at KKI and the Johns Hopkins University School of Medicine, and collaborators at the National Institutes of Health (NIH).

Research Projects

Investigation of Simvastatin Therapy in Smith-Lemli-Opitz Syndrome

This study is a collaborative effort between KKI and NIH. Subjects with SLOS will enter into a 2-year double blind study of cholesterol supplementation plus placebo versus cholesterol supplementation plus simvastatin. It is hypothesized that simvastatin will increase production of cholesterol via upregulation of the necessary enzyme rather than decrease cholesterol production. The goal of this clinical research protocol is to test the clinical efficacy and safety of simvastatin therapy as an addition to cholesterol supplementation in mild to classical SLOS patients using a double-blind, placebo-controlled crossover design.

Funded by the General Clinical Research Center (NIH) of the Johns Hopkins Medical Institutions.

SLOS Behavioral Phenotype Study

The efforts to characterize the behavioral phenotype of Smith-Lemli-Opitz Syndrome were first begun in 1998. This on-going project is now focusing on the changes in behavior over time and the treatment that can be used to help with behavioral difficulties. The study showed that Smith-Lemli-Opitz syndrome was found to be highly associated with autism. It was demonstrated that 9 of the 17 subjects (53%) met the Autism Diagnostic Interview (ADI-R) criteria for the diagnosis of autism (AJMG 2001).

Faculty Involved

Richard Kelley, M.D., Ph.D.
Julia O'Connor, Ph.D.
Elaine Tierney, M.D.


Nowaczyk, MJM, Tierney E, "Smith-Lemli-Opitz Syndrome," Demystifying Genetic Syndromes, National Association for the Dually Diagnosed Publishing, Kingston, New York, in press.

Tierney E, Nwokoro N, Porter FD, Freund LS, Ghuman JK, Kelly RI (2001). Behavior phenotype in the RSH/Smith-Lemli-Opitz syndrome. American Journal of Medical Genetics, 98:191-200.

Tierney E, Nwokoro NA, Kelly RI (2000). Behavioral phenotype of RSH/ Smith-Lemli-Opitz syndrome. Mental Retardation and Developmental Disabilities Research Reviews, 6 (2):131-134.

Smith-Lemli-Opitz Syndrome Resources

See Family Resources: Smith-Lemli-Opitz-Syndrome