The patient, a 15-year-old girl, is the second oldest known survivor with 18-trisomy. Mosaicism seems unlikely as no normal cells were found in blood and skin cultures. The physical appearance of individuals with 18-trisomy may become less characteristic with survival past the first few months of life.
Surana RB, Bain HW, Conen PE. 18-Trisomy in a 15-Year-Old Girl. Am J Dis Child. 1972;123(1):75-77. doi:10.1001/archpedi.1972.02110070125021