A rare genetic overlap: Case report of Bardet–Biedl syndrome, Perrault syndrome, and occulocutaneous albinism

We hereby present a rare association of Bardet–Biedl syndrome (BBS), Perrault syndrome, and occulocutaneous albinism (OCA). A 15-year-old girl presented with a history of weight gain, hyperphagia since 3 years of age, and secondary amenorrhea for 1 year along with delayed motor milestones. The body mass index was 36.1 kg/m 2 (>120% of 95th centile). High arched palate, dental crowding, low set ears, nystagmus, and hypotonia were observed. There was bilateral albinotic fundus, retinitis pigmentosa, and mild hearing loss. Investigations indicated hypergonadotropic hypogonadism. BBS was suspected based on Beales diagnostic criteria. But there were few atypical features like deafness, hypergonadotropic hypogonadism, and albinotic fundus, which were not explained by BBS alone. So the patient underwent genetic testing. Genetic testing identified mutation in genes CEP290, HSD17B4, and OCA2 suggestive of BBS, Perrault, and OCA, respectively. The patient was advised lifestyle modification and underwent treatment for ovarian insufficiency. This is the first case report highlighting a rare association of BBS, Perrault, and OCA, which was not reported previously.