Differential diagnosis:
Alström syndrome , which is distinguished from BBS by the absence of polydactyly and preserved cognitive function.
McKusick-Kaufman syndrome , which is recognised from BBS by the absence of retinal disease, obesity, developmental disabilities and increased incidence of congenital heart disease.
Senior-Løken syndrome , which is marked from BBS by the absence of obesity, polydactyly, hypogonadism, and genitourinary malformations.
Laurence-Moon syndrome , which is distinct from BBS by presence of spasticity and absence of polydactyly
Our patient diagnosis was Bardet Bidel syndrome as she fulfilled all sex items of primary features (obesity, retinitis pigmentosa, postaxial polydactyly, renal abnormalities, learning disabilities and genitourinary malformations) in addition to two secondary features (developmental delay and left ventricular hypertrophy).