Trisomy 18 at age 21 years.

Here we report on a woman with non-mosaic trisomy 18, who is now 21 years old. She has the characteristic face of older trisomy 18 survivors, marked kyphoscoliosis, spastic quadriplegia with contractures, and profound mental retardation. She has pyorrhea with loss of three canine teeth. At 20.5 years, she had her first menstrual cycle with development of secondary sexual characteristics.