Case report of Prader -Willi syndrome

Abstract

Prader-Willi syndrome (PWS) is a complex genetic disorder, characterized by neonatal hypotonia, delayed development, short stature, childhood obesity, hypogonadism, characteristic facial features, and other features . It can be considered to be an autosomal dominant disorder and is caused by deletion or disruption of a gene or several genes on the proximal long arm of the paternal chromosome 15 or maternal uniparental disomy 15, because the genes on the maternal chromosome 15 are virtually inactive through imprinting. This region contains genes that are epigenetically imprinted. We report 12-years old girl with Prader-Willi syndrome. At the day of her birth, she had severe hypotonia, her physiological reflexes were very indolent, also she could not suck or swallow herself. At the age of 12 the patient was admitted for genetic counselling. All laboratory tests for newborns were performed which showed normal results, including karyotipe test (46XX). Neurosonography showed asymetrical, rounded ventricles which suggested hypoxic ischemic changes in the brain. Phenotypically, almond-shaped eyes, prominent nasal bridge and brachydactyly were observed. Moreover, defects in the internal organs, retardation and cysts in the brain were also observed. After the consultation, fluorescent in situ hybridization (FISH) cytogenetic test was carried out to verify the hypothesis of Prader-Willi syndrome. The results showed 15q11 region deletion in 100% of interphase nuclei of lymphocyte culture. The phylogenetic tree was constructed and it showed that patient‘s father is a carrier. This case shows the importance of genetic testing when patients are suffering from severe hypotonia.