IDH1 p.R132H was the most common mutation found in brain grade II diffuse astrocytomas (54%, 7/13), while only 2 spine grade II diffuse astrocytomas cases harbored IDH mutations (12.5%, 2/16; Fisher test: p = 0.041), and these mutations were non-canonical IDH mutations. The gene discussed is IDH1; the disease is diffuse astrocytoma.