Bardet-Biedl syndrome comprises several different diseases with a similar constellation of findings, including pigmentary retinopathy (with or without pigment deposits), obesity, polydactyly, hypogonadism, and cognitive disability. Patients with Bardet-Biedl syndrome typically demonstrate a severe but variable form of rod–cone dystrophy, usually sine pigmento, with a bull’s-eye atrophic maculopathy (Fig 14-1). These disorders were previously classified as autosomal recessive, but molecular studies strongly suggest that many are multigenic, with 2 or even 3 different mutations contributing to the phenotype. Increasing evidence suggests that the primary functions of the proteins affected in Bardet-Biedl syndrome are to mediate and regulate microtubule-based intracellular transport processes.
Table 14-1 Selected Systemic Diseases With Pigmentary Retinopathies
Figure 14-1 Bardet-Biedl syndrome. A, B, Color fundus photographs show pigmentary alterations in the periphery and macula. C, Color fundus photograph of the sibling of the patient in (A) and (B) demonstrates similar macular changes. D, Clinical photograph of a patient’s foot with 6 toes (polydactyly).
(Courtesy of David Sarraf, MD.)
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.