Neonatal diagnosis of Prader‐Willi syndrome and its implications

Abstract

Although Prader‐Willi syndrome (PWS) patients usually first present with neonatal hypotonia and feeding difficulty, they later show hyperphagia, obesity and men tal retardation. Since deletions of chromosomes 15qll‐ql3 are noted in most PWS patients cytogenetic analysis allows one to diagnose infants suspected of PWS with a greater certainty. We report on 5 hypotonic infants clinically suspected of PWS in the first 3 months of life, whose diagnosis was confirmed by cytogenetic studies showing monosomy of 15qll‐ql3. Early diagnosis of PWS can lead to prevention of obesity, but counseling of parents has been difficult. Although there are significant benefits to the early diagnosis of PWS, the cost‐effectiveness and practi cality of screening all hypotonic infants using high resolution cytogenetic analysis has not been addressed systematically.