P-7. Huntington?s disease in the Cypriot population: direct molecular diagnosis since 1994.

Huntington disease (HD) is an autosomal dominant neurodegenerative disorder caused by CAG repeats expansion in the huntingtin gene. The main clinical features of the disease are progressive chorea, speech and gait disturbances, depression and dementia. The dynamic mutations may lead to increasing of the CAG repeats number from one generation to the next, worsening the progression of the disease and decreasing the age of onset. HD was mapped to chromosome 4p16.3 in 1983 and the HD-gene was isolated in 1993. Direct PCR- analysis of the mutation has been made available in Cyprus, through the Cyprus Institute of Neurology and Genetics (CING) since 1994. Furthermore, since 2000 this laboratory participates in external quality assessment for this disease through the European Molecular Genetics Quality Network (EMQN). Approximately 130 individuals, including patients, presymptomatic carriers and healthy people from the Cypriot population were tested. We studied and offered molecular genetic services in nine Cypriot families. Prenatal diagnosis was also offered in one of these families. The aim is to provide extended epidemiological information of HD in Cyprus. The vast majority of families originate from the southern Famagusta district, where there appears to exist a genetic cluster of HD. Cypriot pathological alleles range from 37 to 54 CAG repeats in 47 HD diagnosed individuals, while the normal range for 180 tested chromosomes is 9-27 CAG repeats. A juvenile case revealed a CAG repeat over 65. Phenotype/genotype correlations for Huntington Disease in Cyprus will be presented.