These findings suggest that the PMM2 is responsible for CDG1 in the Japanese as well as in Caucasians, and CDG1 may be the diagnosis in OPCA of neonatal onset, more often than currently thought.
One specific haplotype was found to be markedly overrepresented in CDG I patients from a geographically distinct region in Scandinavia, strongly indicating that CDG I families in this region share the same ancestral CDG1 mutation. furthermore, analysis of the extent of the common haplotype in these families indicates that the CDG1 gene is located in the region defined by markers D16S513-AFMa284wd5-D16S768-D16S406-D16S502 .
We found eleven different missense mutations in PMM2 in 16 CDG1 patients from different geographical origins and with a documented phosphomannomutase deficiency.