Clinical and Molecular Characterization of Prader-Willi Syndrome

To describe the clinical presentations and molecular diagnosis to aid the clinicians in early diagnosis and appropriate management of Prader-Willi syndrome (PWS).

Thirty-four clinically diagnosed PWS cases were enrolled after obtaining informed consent/assent. Demographic details, clinical data and anthropometry were recorded using structured proforma. The facial dysmorphology was evaluated. Appropriate genetic testing was performed to confirm the diagnosis.

At diagnosis, the most common clinical features included obesity (59%) and short stature (53%). Distinct dysmorphic features were observed in 67%. Neonatal hypotonia with feeding difficulty, delayed development in infancy and childhood behavioral problems were reported in 94%, 94% and 74% respectively. Food seeking behavior and hyperphagia was reported in 67%. Seizures were reported in 47%. All children had underdeveloped external genitalia. Growth hormone (GH) deficiency and impaired glucose tolerance were found in 56% and 50% respectively. Sleep related problems were seen in 67%. Skin and rectal picking were reported in 67%. FISH confirmed micro-deletion was found in 64.7% and abnormal methylation in 35%, of which uniparental disomy was confirmed in 14.7%.

Clinical suspicion is vital for early detection of PWS. Confirmation of the diagnosis requires complex multi-tier molecular genetic testing.