Ancestral Origin of the First Indian Families with Myotonic Dystrophy Type 2
What is it about?
Myotonic dystrophy type 2 (DM2) is caused by a CCTG repeat expansion in intron 1 of the CCHC-Type Zinc Finger Nucleic Acid Binding Protein (CNBP) gene. Previous studies indicated that this repeat expansion originates from separate founders. This study was set out to determine whether or not patients with DM2 originating from European and non-European countries carry the previously described European founder haplotypes. Of 41 patients, the haplotype could be assigned to the previously described Caucasian haplotypes. Three patients from Morocco and Portugal had a haplotype identical to the earlier reported Moroccan haplotype. Twelve patients from India and Suriname, however, carried a haplotype that seems distinct from the previously reported haplotypes. Three individuals could not be assigned to a specific haplotype. The ancestral origin of DM2 in India might be distinct from the Caucasian families and the solely described Japanese patient. However, we were unable to establish this firmly due to the limited genetic variation in the region surrounding the CNBP gene.
Why is it important?
This study was set out to determine whether or not patients with DM2 originating from European and non-European countries carry the previously described European founder haplotypes. The ancestral origin of DM2 in India might be distinct from the Caucasian families and the solely described Japanese patient.