* Department of Gynecology, Félix Guyon'Hospital, 97400 Saint-Denis, Ile de la Réunion, France;
** Gynecologist, Moufia'street, 97400 Saint-Denis, Ile de la Réunion, France;
*** Department of Neonatology, Félix Guyon'Hospital, 97400, Saint-Denis, Ile de la Réunion, France.
Prader-Willi syndrome is characterized by pre and postnatal muscular hypotonia, thus giving an appearance of severe brain damage. Prader-Willi syndrome consists of low birth weight and early feeding problems with infantile hypotonia (floppy baby). Severe obesity appears later, associated with hyperphagia (obsessive-compulsive behavior). Profound hypotonia can cause asphyxia.
The children suffered with this condition have developmental delay (mild to moderate mental retardation), short stature with hypogenitalism in males and hypogonadism. Short stature and mild facial dysmorphism are present (rounded face, low forehead, almond shaped eyes, squinting). Prader-Willi syndrome is a neuroendocrine disorder.
This is a 36-year-old woman (G4P3), referred to our antenatal unit at 33 weeks of pregnancy due to a polyhydramnios without intra-uterine growth restriction and premature uterine contractions. The previous ultrasound scans at 13 and 22 weeks were normal and so was the triple test. Family history was unremarkable. Our ultrasound examination at 35 weeks revealed:
No other abnormalities were seen. An amniocentesis was performed for uterine decompression and karyotyping (the karyotype was normal, 46 XY). The patient delivered at 37th week by cesarean section. The baby was hypoxic with decreased respiratory movements and had problems with swallowing later. Physical examination and neurological examination found muscular hypotonia without other external abnormalities. The hypotonia had lasted during the first month of life with slow improvement. The baby required prolonged oxygen therapy.
Complementary examinations (cerebral transfontanellar sonography, CT, MRI and EEG) were normal. A muscular biopsy was done with normal histological results. Steinert dystrophia was eliminated by DNA analysis.
Molecular analysis using microsatellite polymorphisms showed that the fetus had maternal disomy for chromosome 15. Southern blot analysis revealed a typical Prader-Willi syndrome abnormal methylation profile. The Prader Willi was the final diagnosis.
Images 1, 2: 35th week of pregnancy. Image 1 - cryptorchidy of the fetus; Image 2 - the fetal bladder was almost constantly full during our examinations.