PRADER–WILLI SYNDROME

Abstract

Summary The major manifestations of this multisystem disorder include prenatal and neonatal central hypotonia causing poor suck and infantile failure-to-thrive, characteristic facial appearance, developmental delay/generally mild intellectual disability, childhood onset obesity, short stature for the family, hypogonadism causing genital hypoplasia and pubertal insufficiency, and a characteristic behavior disorder. Obesity-related complications are the major cause of morbidity and mortality. The cause of Prader?Willi syndrome is the absence of paternal contribution at chromosome 15qll-13, a region involving genomic imprinting, through deletion, maternal uniparental disomy, or an imprinting defect. Several specific genes in this region have been identified, though how they cause the manifestations of the disorder is still unclear. Clinical diagnostic criteria for Prader?Willi syndrome have been published, but confirmation requires diagnostic testing, which is clinically available. Management is mostly supportive because no definitive treatment is known. Growth deficiency and abnormal body composition respond well to growth hormone replacement.