A case of simple trisomy 13, confirmed by G-banded chromosome analysis, is reported in a Caucasian female over 5 years of age. There is no cytogenetic evidence available for mosaicism in the propositus or her parents. The patient's salient clinical features are: profound mental and motor retardation; microcephaly with trigonocephaly; ear malformations; small, sunken eyes; unusual eyebrows; cleft lip and palate; bulbar nose; coloboma iris; polydactyly; unusual dermatoglyphic patterns; large adductor thumbs; enlarged great toes; multiple capillary haemangiomas; club feet; inguinal and umbilical hernias; hyperconvexed fingernails; and seizure disorder.