Moyamoya disease-5 (MYMY5; 614042) is caused by mutation in the ACTA2 gene (102620) on the long arm of chromosome 10 (10q23.3); and moyamoya disease-6 with achalasia (MYMY6; 615750) is caused by mutation in the GUCY1A3 gene (139396) on the long arm of chromosome 4 (4q32). Loci for the disorder have been mapped to the short arm of chromosome 3 (MYMY1) and the long arm of chromosome 8 (8q23) (MYMY3; 608796). See also MYMY4 (300845), an X-linked recessive syndromic disorder characterized by moyamoya disease, short stature, hypergonadotropic hypogonadism, and facial dysmorphism, and linked to q25.3, on chromosome 17.In Japan the overall incidence is higher (0.35 per 100,000). In North America, women in the third or fourth decade of life are most often affected, but the condition may also occur during infancy or childhood. These women frequently experience transient ischaemic attacks (TIA), cerebral hemorrhage, or may not experience any symptoms at all. They have a higher risk of recurrent stroke and may be experiencing a distinct underlying pathophysiology compared to patients from Japan.Moyamoya disease can be either congenital or acquired. Patients with Down syndrome, sickle cell anemia, neurofibromatosis type 1, congenital heart disease, fibromuscular dysplasia, activated protein C resistance, or head trauma can develop moyamoya malformations. It is more common in women than in men, although about a third of those affected are male. Pathophysiology
The disease moyamoya, which is a Japanese mimetic word, gets its characteristic name due to the appearance of smoke on relevant angiographs resultant from the tangle of tiny vessels in response to stenosis.
Cutis verticis gyrata is a medical condition usually associated with thickening of the scalp. The condition is identified by excessive thickening of the soft tissues of the scalp and characterized by ridges and furrows, which give the scalp a cerebriform appearance. Clinically, the ridges are hard and cannot be flattened on applying pressure. Patients show visible folds, ridges or creases on the surface of the top of the scalp. The number of folds can vary from two to roughly ten and are typically soft and spongy. The condition typically affects the central and rear regions of the scalp, but sometimes can involve the entire scalp. Hair loss can occur over time where the scalp thickens, though hair within any furrows remains normal. Thus far, due to the (apparent) rarity of the condition, limited research exists and causes are as yet undetermined. What is known, is that the condition is not exclusively congenital. The condition was first reported by Jean-Louis-Marc Alibert in 1837, who called it cutis sulcata. A clinical description of the condition was provided by Robert in 1843 and it was named by Paul Gerson Unna in 1907. It has also been called Robert-Unna syndrome, bulldog scalp, corrugated skin, cutis verticis plicata, and pachydermia verticis gyrata. Cause
At this time, causes are unknown, but it is believed to not be congenital. Diagnosis
There is no clinical diagnosis for CVG as cases are rarely seen and are often comorbid with other conditions. Classifications
CVG is classified according to the presence, or lack of underlying cause.