There are numerous reports of multi-system genetic disorders with obesity. Many have a characteristic presentation
and several, an overlapping phenotype indicating the likelihood of a shared common underlying
mechanism or pathway. By understanding the genetic causes and functional perturbations of such syndromes
we stand to gain tremendous insight into obesogenic pathways. In this review we focus particularly
on Bardet-Biedl syndrome, whose molecular genetics and cell biology has been elucidated recently, and
Prader-Willi syndrome, the commonest obesity syndrome due to loss of imprinted genes on 15q11–13. We
also discuss highlights of other genetic obesity syndromes including Alstrom syndrome, Cohen syndrome,
Albright’s hereditary osteodystrophy (pseudohypoparathyroidism), Carpenter syndrome, MOMO syndrome,
Rubinstein-Taybi syndrome, cases with deletions of 6q16, 1p36, 2q37 and 9q34, maternal uniparental
disomy of chromosome 14, fragile X syndrome and Börjeson-Forssman-Lehman syndrome.
