TUBB4A and Alzheimer disease: Tubulin beta 4A class IVa (TUBB4A, OMIM *602662), which is a member of the beta tubulin family, a subunit of microtubules, is reported to cause AD Dystonia 4, torsion (OMIM #128101) and AD Leukodystrophy, hypomyelinating, 6 (OMIM #612438) [15].