Different phenotypic expression in monozygotic twins with Huntington disease
Article first published online: 18 JUL 2003
Copyright © 2003 Wiley-Liss, Inc.
American Journal of Medical Genetics Part A
Volume 124A, Issue 1, pages 89–91, 1 January 2004
How to Cite
Anca, M.H., Gazit, E., Loewenthal, R., Ostrovsky, O., Frydman, M. and Giladi, N. (2004), Different phenotypic expression in monozygotic twins with Huntington disease. Am. J. Med. Genet., 124A: 89–91. doi: 10.1002/ajmg.a.20328
- Issue published online: 11 DEC 2003
- Article first published online: 18 JUL 2003
- Manuscript Accepted: 22 APR 2003
- Manuscript Received: 1 NOV 2002
- Huntington disease;
Monozygotic (MZ), 46-year-old, male twins, carrying the same Huntington disease (HD) mutation, presented with a different clinical course. In one of the twins, the disease process started at the age of 32 years with chorea, dysarthria, and a depressed mood. Over 14 years, the disease progressed to total functional dependence. The second twin presented at age 35 with gait disturbances. His behavior became aggressive with an obsessive pattern, whereas the motor features included hypokinesia, rigidity, gait unsteadiness, and dysarthria. This is the first report of genetic identity associated with different age of disease onset as well as a different motor and behavioral phenotype. Postzygotic events are a likely explanation for the observed differences of phenotype in these genetically identical twins. © 2003 Wiley-Liss, Inc.