P135 – 2956: Prader-Willi syndrome, not so rare among the floppy infants

Abstract

Objective Prader-Willi syndrome (PWS) is one of the more common causes of severe neonatal hypotonia. PWS is seen in 1:15000 newborn. The clinical picture is characteristic and different to that of neuromuscular and metabolic diseases. Early diagnoses is important for treatment. During childhood and adulthood several symptoms will arise, and knowledge about PWS is important for management and survival. Methods Genetics and clinical picture are described. Results In PWS paternal genetic information from chromosome 15q is missing, either as paternal deletion 15q, maternal uniparental disomia (UPD) of chromosome 15, or by an imprinting mutation on paternal 15q. PWS can be confirmed by a DNA methylation test. Del 15q (ca. 65% of cases) is detected by an array CGH test. In pregnancy reduced foetal movements, oligo or poly hydramnion can be seen. At birth breech presentation is common. Apgar score is often normal, but followed by severe hypotonia. The child sleeps, does not cry, is not interested in eating or sucking. Breathing is normal. Tube feeding is necessary in weeks or months. Slight dysmorphism ban be seen: Small bifrontal diameter, almond shaped eyes, micrognathia, open triangular mouth, small hands and feet. 95% of boys have cryptorchism. The motor function gradually improves, milestones are delayed. From age 1–2 years a peculiar interest for food and eating arises followed by a morbid obesity, but only if food is not controlled. Growth hormone deficiency, hypogonadism, abnormal temperature regulation, abnormal sleep pattern, sleep apnea, scolioses, behavioural problems and mild to moderate mental retardation are characteristic. Psychiatric diseases are seen in adults. Conclusion Early diagnose is important and possible. Many clinical symptoms can be treated successfully to secure quality of life for patients and family. Especially it is possible, to prevent severe overweight and obesity related diseases including early death.