Microcephalic osteodysplastic primordial dwarfism type II (MOPDII), the most common form of microcephalic primordial dwarfism, is characterized by extreme short stature and microcephaly along with distinctive facial features. Associated features that differentiate it from other forms of primordial dwarfism and that may necessitate treatment include: abnormal dentition, a slender bone skeletal dysplasia with hip deformity and/or scoliosis, insulin resistance / diabetes mellitus, chronic kidney disease, cardiac malformations, and global vascular disease. The latter includes neurovascular disease such as moyamoya vasculopathy and intracranial aneurysms (which can lead to strokes), coronary artery disease (which can lead to premature myocardial infarctions), and renal vascular disease. Hypertension, which is also common, can have multiple underlying causes given the complex comorbidities.

Moyamoya disease is a progressive cerebral angiopathy characterized by bilateral internal carotid artery stenosis and abnormal collateral vessels. The abnormal vessels resemble a 'puff of smoke' (moyamoya) on cerebral angiogram. Affected individuals can develop transient ischemic attacks and/or cerebral infarction, and rupture of the collateral vessels can cause intracranial hemorrhage (summary by Kamada et al., 2011). For a general phenotypic description and a discussion of genetic heterogeneity of moyamoya disease, see MYMY1 (252350).

Any familial thoracic aortic aneurysm and aortic dissection in which the cause of the disease is a mutation in the ACTA2 gene.

This multisystem disorder is characterized by moyamoya disease, short stature, hypergonadotropic hypogonadism, and facial dysmorphism. Other variable features include dilated cardiomyopathy, premature graying of the hair, and early-onset cataracts. Moyamoya disease is a progressive cerebrovascular disorder characterized by stenosis or occlusion of the internal carotid arteries and the main branches, leading to the development of small collateral vessels (moyamoya vessels) at the base of the brain. Affected individuals can develop acute neurologic events due to stroke-like episodes (summary by Miskinyte et al., 2011). For a general phenotypic description and a discussion of genetic heterogeneity of moyamoya disease, see MYMY1 (252350).

Moyamoya disease is a cerebrovascular disorder caused by stenotic changes of terminal portions of the internal carotid arteries accompanied by surrounding fine arterial collateral vessels. These vascular networks resemble a 'puff of smoke' (Japanese: moyamoya) in angiographic imaging (summary by Roder et al., 2011). For a general phenotypic description and a discussion of genetic heterogeneity of moyamoya disease, see MYMY1 (252350).

Moyamoya disease-6 (MYMY6) is a progressive vasculopathy characterized by occlusion of the terminal portion of the internal carotid arteries and its branches, and the formation of compensatory neovascularization and the moyamoya, or 'puff of smoke,' appearance of these vessels on angiogram. Affected individuals may present with ischemic strokes, intracerebral hemorrhage, or transient ischemic attacks. Patients with MYMY6 usually present early in life with achalasia. Hypertension and Raynaud phenomenon may be associated features (summary by Wallace et al., 2016; Herve et al., 2014). For a general phenotypic description and a discussion of genetic heterogeneity of moyamoya disease, see MYMY1 (252350).