Human piebaldism has been observed to be associated with a very wide range and varying degrees of endocrine disorders, and is occasionally found together with heterochromia of the irises, congenital deafness, or incomplete gastrointestinal tract development, possibly all with the common cause of premature cutting off of human fetal growth hormone during gestation. Piebaldism is a kind of neurocristopathy, involving defects of various neural crest cell lineages that include melanocytes, but also involving many other tissues derived from the neural crest. Oncogenic factors, including mistranscription, are hypothesized to be related to the degree of phenotypic variation among affected individuals. Genetics
Piebaldism is an autosomal dominant hereditary condition, which tends to produce high rates of inheritance and long chains of generational transmission. All who inherit the gene have at some time in life evidence of piebald hypopigmentation of the hair or skin, most likely both.Piebaldism may be associated with the genes KIT or SNAI2. Diagnosis
Usually diagnosed at birth with the appearance of patches of white skin on the arms, legs, stomach, forehead, and a white lock of hair. History
Early photographers took many photographs of African people with piebaldism as a form of entertainment and exoticism, and George Catlin is believed to have painted several portraits of Native Americans of the Mandan tribe who were affected by piebaldism.Historically, persons with extensive piebaldism have experienced abuse of the sort still suffered in the present by albinos, especially in Africa.
In atherosclerosis, the walls of arteries are damaged, leading to the deposition of fat and immune cells, and ultimately the accumulation of immune cells laden with fat. In moyamoya, the inner layer of the carotid artery proliferates within the arterial lumen. The artery also fills with blood clots, which may cause strokes.Moyamoya disease tends to affect adults in the third to fourth decade of life. In children it tends to cause strokes or seizures. In adults it tends to cause strokes or bleeding. The clinical features are strokes, recurrent transient ischemic attacks (TIAs), sensorimotor paralysis (numbness and paralysis of the extremities), convulsions and/or migraine-like headaches. Moreover, following a stroke, secondary bleeding may occur. Such bleeding, called hemorrhagic strokes, may also stem from rupture of the weak neovascular vessel walls. Diagnosis
Cerebral angiography is the gold standard of diagnosing moyamoya disease and its progression.