Hernando I, Alvarez V, García Martínez A, Salas Puig J, Fernández Uría D, Martínez C, Vidal Sánchez J A, Lahoz C, Coto E
Servicio de Genética, Hospital Central de Asturias, Oviedo.
Neurologia. 1999 Jan;14(1):11-5.
AIM AND PATIENTS: To analyse 38 patients with Huntington's disease from 27 families.
The CAG repeat at the huntingtin gene was expanded between 40 and 72 times. The size in normal chromosomes varied from 12 to 30 repeats. We found a significantly negative correlation between the number of CAG-repeats and the age of clinical manifestations. However, age and clinical characteristics of the first symptoms were highly variable between patients with a similar size of the expanded allele. Patients who inherited the disease from their fathers showed a higher number of repeats than those who received the disease from their mothers. However, in one case of father to son transmission we observed a reduction of the number of CAG repeats.
These data make it difficult to use the molecular analysis for the presymptomatic diagnosis of clinical course in individuals carrying the expansion.
