A clinical case of trisomy on chromosome 18 (Edwards Syndrome)

Abstract

Edwards syndrome (trisomy on chromosome 18) is a genetic disorder caused by the presence of an extra copy of the eighteenth chromosome in humans. It is the second most common chromosomal disorder after Down syndrome. The frequency of Edwards syndrome among newborns is 1:5000–1:7000. The ratio of boys to girls is 1:3. The karyotype of sick girls and boys is 47, XX+18, 47, XY+18, and 47, XY+18, respectively. Patients are born with low birth weight (about 2 kg), they have delayed growth and development, mental retardation, wide fontanels at birth and open cranial sutures, the thorax is wider and shorter than normal, the mandible and mouth opening are small. The eye slits are narrow and short, the auditory orifices are deformed and sometimes absent. There are defects of the heart and large vessels, hypoplasia of the cerebellum and corpus callosum. 5–10% survive to the age of one year, all survivors are profound oligophrenics [1–4].