Bardet-Biedl Syndrome in an African-American Patient: Should the Diagnostic Criteria Be Expanded to Include Hydrometrocolpos?

Abstract

Bardet-Biedl Syndrome (BBS) is a multisystemic disorder diagnosed on the basis of a combination of primary and secondary clinical features that include retinal dystrophy, obesity, polydactyly, cognitive dysfunction, and renal malformations. We report a unique case of BBS in a 13-year old girl of African-American descent who presented with retinitis pigmentosa, obesity, polydactyly, learning disabilities, precocious puberty, hypertension, renal cysts, and Hirschprung disease. Further evaluation revealed a history of precocious puberty, which is antithetical to the common manifestations of BBS, while neuroimaging was suggestive of periventricular leukomalacia and neuro-electrophysiologic studies revealed diffuse cerebral disturbance, which may contribute to her neurological abnormalities. The patient was also diagnosed with hydrometrocolpos, a finding typical of McKusick-Kaufman Syndrome (MKKS) but infrequent in other disorders. This observation, together with recent findings in some mouse models of BBS, raises the question of whether hydrometrocolpos should be considered as an additional diagnostic criterion for BBS to be used in females in parallel to the criterion of hypogonadism in males, thereby improving diagnostic sensitivity.

Keywords:

• Bardet-Biedl syndrome
• retinitis pigmentosa
• hydrometrocolpos
• genetic testing