Patients with biochemically confirmed SLOS are being treated with cholesterol supplementation and antioxidant medication. They are carefully monitored with visits to clinic, laboratory testing including cholesterol and 7-dehydrocholesterol levels, vitamin levels, blood counts and liver and kidney function. On a serial basis, no more often than once a year, the patients undergo a series of tests under anesthesia, including electroretinogram (ERG), brainstem audiometry (ABR), and ophthalmologic exam under anesthesia to follow pigmentary retinopathy.