The syndrome of spastic paraplegia, intellectual disability, nystagmus, and obesity (SINO; MIM# 617296) is an autosomal dominant rare disease with birth defects of cranial and maxillofacial deformity, severe intellectual disability, and obesity, which was first described and linked to heterozygous nonsense kinase D-interacting substrate of 220 kDa (KIDINS220/ARMS) mutations by Josifova et al. (2016) in three unrelated patients. Here, KIDINS220 is linked to obesity due to melanocortin 4 receptor deficiency.