The most common clinical features include ischemic stroke in NOTCH3, COL4A1, and ADA2 mutations; cognitive disorder in NOTCH3, HTRA1, COL4A2, and CTSA mutations; developmental delay in COL4A1/2 mutations; psychiatric features in CTSA, HTRA1 and TREX1 mutations; seizures in COL4A1/2 mutations; vertigo in CTSA mutations; and headache in TREX1 mutations (43). The gene discussed is HTRA1; the disease is ischemic stroke.