Syndromic obesity: clinical implications of a correct diagnosis

Background: Although individual occurrence is rare, syndromic obesity with mental retardation has been reported in conjunction with 140 different diseases. Case presentation: The patient was born at term after a pregnancy complicated by threatened miscarriage. A diagnosis of Bardet-Biedl syndrome (BBS; OMIM #209900) was made in another hospital when she was 8 years old, but other clinical problems emerged subsequently. She came to our attention for the first time when she was 14 years old. The clinical picture, characterized by the presence of ophtalmological, renal, endocrinological, and liver disorders associated with a peculiar weight growth pattern, was more suggestive for Alstrom syndrome (ALMS; OMIM #203800); consequently, a genetic study was performed. Genetic analysis revealed a novel compound heterozygous frameshift mutation on exon 8 of ALMS1 (c. [3251_3258delCTGACCAG] and c. [6731delA]), which has not previously been described. Conclusion: Early onset of retinal degeneration associated with obesity represents a diagnostic challenge in paediatric and genetic practice, although the absence of skeletal abnormalities and developmental delay could help in addressing the clinical diagnosis. Confirmation of clinical suspicion by genetic analysis has been diriment in this case, since only a single gene is known to cause ALMS.