TUBB2B and Cowden disease: According to the literature and derived from our data, patients with TUBA1A compared with TUBB2B tubulinopathy more frequently show severe MCDs such as microlissencephaly, lissencephaly, and agyria.4,16 Comparatively, less severe MCDs such as PMG and PMG-like CD, which are also seen in connatal infections, appear more specific for TUBB2B tubulinopathy, therefore not prompting early genetic testing.35,36