PCSK1 and obesity due to melanocortin 4 receptor deficiency: Recently, the PCSK1 nonsynonmous variants rs6232 (encoding N221D) and rs6234-rs6235 (encoding the Q665E-S690T pair) have been shown to be consistently associated with obesity risk (OR = 1.34 and 1.22, respectively) in European populations including a total of 13,659 individuals from eight independent case-control or family-based cohorts [4].