Late-onset and typical Huntington disease families from Crete have distinct genetic origins

Huntington disease mutation in Venezuela: age of onset, haplotype analyses and geographic aggregation

“…Of the four promoter region polymorphisms for which frequencies are available (Coles et al 1997;Kartsaki et al 2006), the 1;G;C haplotype appears to be the most frequent in all studied populations, including our sample, although with interethnic differences. The 4;G;C haplotype is almost absent in normal Caucasoids, but its frequency in control Japanese chromosomes is around 10% (Coles et al 1997); in our control sample, it is 12%.…”

Late onset Huntington Disease: Clinical and genetic characteristics of 34 cases

“…In the present study 68% (23/34) of the subjects had no known family history of HD. The frequent lack of a clear family history of HD in this series is undoubtedly related to the small CAG repeat size occurring in other family members 16, 17 . Although the expansion tends to remain about the same size in affected persons in such families there is always the possibility of further expansion and concomitant earlier onset.…”

A systematic review of the intergenerational aspects and the diverse genetic profiles of Huntington's disease

“…Another survey conducted on the Crete island, Greece, studying HD in 33 individuals, reported that the shortest HD-causing allele contained 36 CAG copies and the longest allele had 42 CAG repeats (Kartsaki et al, 2006). In India, the shortest HD allele identified contained 41 CAG repeats and the longest allele, 56 CAG repeats (Pramanik et al, 2000).…”