FBN3 and obesity due to melanocortin 4 receptor deficiency: FBN3 variants could be, therefore, associated with a distinct BBS phenotype and partially overlapping with fibrillin-related disorders and characterized by developmental delay and cognitive impairment, obesity, dental, and genital anomalies, in association with other more variable clinical abnormalities including ocular defects, abnormal development of the extremities, cardiovascular, and palate anomalies (Table 1).