TUBB3 and Insulin resistance: However, this pleiotropic effect is not unique to TUBA4A, as similar divergent phenotypes have been observed with other variants such as TUBB3:p.Arg262His - implicated in cortical malformations, peripheral neuropathy and endocrine malfunction,44 and LMNA:p.Arg644Cys, which has been associated with muscular dystrophy, cardiomyopathy, insulin resistance, lipodystrophy and peripheral neuropathy.45