[A new case of pentasomy X].

Cytogenetic investigations of children with psychomotor retardation gave evidence of pentasomia X in a twelve-month-old girl. The chromosome analysis made on the basis of lymphocyte cultures showed a 49,XXXXX caryotype; up to four X-chromatin masses were found. Total ridge count (TRC) was diminished to the very low value of 15. The clinical symptoms of our case were compared with the others published in earlier papers. In accordance with the other authors we found a low birth weight, oligophrenia, multiple abnormalities of the craniofacial skeleton (hypertelorism, epicanthus, broad root of the nose, oblique axis of the eyelids), and some minor deformities of the fingers and toes. Less common signs of the syndrome are malformations of the heart and probably the hemiatrophy, especially of the face, a rather pronounced finding in our case.