A novel Sac I RFLP in the 3' untranslated region of the myotonin protein kinase gene

Abstract

We found a novel Sac I polymorphism downstream of CTG repeats in the 3' untranslated region of the myotonin protein kinase (MT-PK) gene. A C to G transition at nucleotide 13,590 in the gene was revealed by Southern blotting and confirmed by sequencing analyses. The allelic frequency of the C:G polymorphism in 63 unrelated Japanese individuals was estimated to be 0.98: 0.02. When Southern blotting is employed in the analysis of the CTG repeat length in the MT-PK gene, this Sac I polymorphism should be taken into consideration.