<unk>  is one of about 150 types of<unk><unk>  in humans. Before birth, these disorders result in the abnormal development of structures including the skin, hair, nails, teeth, and sweat glands.
Most people with<unk>  have a reduced ability to sweat (hypohidrosis) because they have fewer sweat glands than normal or their sweat glands do not function properly. Sweating is a major way that the body controls its temperature; as sweat evaporates from the skin, it cools the body. An inability to sweat can lead to a dangerously high body temperature (hyperthermia), particularly in hot weather. In some cases, hyperthermia can cause life-threatening medical problems.
Affected individuals tend to have sparse scalp and body hair (hypotrichosis). The hair is often light-colored, brittle, and slow-growing. This condition is also characterized by absent teeth (hypodontia) or teeth that are malformed. The teeth that are present are frequently small and pointed.<unk>  is associated with distinctive facial features including a prominent forehead, thick lips, and a flattened bridge of the nose. Additional features of this condition include thin, wrinkled, and dark-colored skin around the eyes; chronic skin problems such as eczema; and a bad-smelling discharge from the nose (ozena).<unk>  is the most common form of<unk><unk>  in humans. It is estimated to affect at least 1 in 17,000 people worldwide.
Hypohidrotic ectodermal dysplasia
Congenital generalized lipodystrophy
Hurler-Scheie syndrome
Sabinas brittle hair syndrome
Familial partial lipodystrophy type 1
Goldstein-Hutt syndrome
Goldenhar syndrome
Tuberous sclerosis