Prader-Willi syndrome (PWS) is considered the most common syndromic cause of life-threatening obesity, occurring in approximately one in 10,000-30,000 live births.1 PWS is associated with the loss of expression of paternal alleles in the PWS region of chromosome 15, without sex differences in prevalence.

A large debate around this topic took place at the IPWSO Conference in Havana, Cuba in November last year.