A defect in tubulin gene alpha-tubulin (TUBA), beta-tubulin (TUBB), and gamma-tubulin (TUBG) leads to defective neuronal migration [5], and this group of disorders is termed as "tubulinopathies." In mammals, gamma-tubulin is highly conserved and is encoded by two genes. The gene discussed is TUBG1; the disease is tubulinopathy.