IDH3A and alpha thalassemia-X-linked intellectual disability syndrome: Previous studies have suggested that these differences could be attributed to molecular expression status, especially isocitrate dehydrogenase (IDH), chromosomal alterations in 1p/19q, alpha-thalassemia X-linked intellectual disability syndrome (ATRX), and O6-methylguanine-DNA methyltransferase (MGMT) (3).