FXN and diabetes mellitus: Of the seven individuals with mutations in the start codon or early in the FXN gene (c.1A>C, c.2delT, c11_12delTC, and c100delG), three had diabetes while only two had scoliosis, and frataxin levels in the blood were notably much higher (average of 88 compared to a range of 10–20 for all other subgroups).