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The syndrome is extremely rare and has been reported in three unrelated families to date, with 10 affected individuals in several generations. These families are not from Japan or Asia, whereas in general the incidence of moyamoya disease (see this term) is highest in Japan and other Asian countries, in comparison with other parts of the world.

Affected patients are all male (X-linked inheritance) and have moyamoya angiopathy (progressive stenosis of the terminal portion of the intracranial internal carotid arteries), short stature, hypergonadotropic hypogonadism, and other variable manifestations including stroke, hypertension, dilated cardiomyopathy (see this term), premature coronary heart disease, premature hair graying, azoospermia, and early bilateral acquired cataract. Moyamoya angiopathy causes cerebral infarcts or hemorrhage and acute neurological symptoms. Facial dysmorphism is characterized by hypertelorism, flared nares, long philtrum, and mild ptosis. Carrier females are not affected.

The genetic cause appears to involve Xq28 deletions removing MTCP1/CMC4and BRCC3 (Xq28) .The specific pathophysiological mechanisms underlying this disorder remain obscure, but appear to involve alteration in DNA repair.

Reported cases are suggestive of a hereditary syndrome with an X-linked recessive pattern of inheritance.