Achard-Thiers syndrome is a rare disorder that occurs primarily in postmenopausal women and is characterized by type 2 (insulin-resistant) diabetes mellitus and signs of androgen excess. The exact cause of this syndrome is unknown....

The term albinism typically refers to oculocutaneous (ok-u-low-ku-TAY-nee-us) albinism (OCA) — a group of inherited disorders where there is little or no production of the pigment melanin. The type and amount of melanin your body produces de...

Amenorrhea facts Amenorrhea refers to the absence of menstrual periods; it may be either primary (meaning a woman never developed menstrual periods) or secondary (absence of menstrual periods in a woman who was previously menstruati...

Argininosuccinic aciduria is a rare inherited disorder characterized by deficiency or lack of the enzyme argininosuccinate lyase (ASL). Argininosuccinate lyase is one of six enzymes that play a role in the breakdown and removal of nitrogen from th...

Polycystic ovary syndrome (PCOS) affects women and is a complex of symptoms that are not necessarily all present in all cases. Some, but not all, affected women have multiple cysts on the ovaries (polycystic ovaries). Other characteristics include...

Hairy tongue is an uncommon, benign condition that is also known as black hairy tongue or lingua nigra. It is characterized by abnormal elongation and blackish or dark brownish discoloration or "staining" of the thread-like elevations (filiform pa...

Hajdu-Cheney syndrome (HCS) is a rare, heritable disorder of connective tissue; only about 50 cases have been reported in the medical literature. The breakdown of bone (osteolysis), especially the outermost bones of the fingers and toes (acroosteo...

CHILD syndrome (an acronym for congenital hemidysplasia with ichthyosiform erythroderma and limb defects) is an inherited disorder, affecting primarily women, that is characterized by ichthyosis-like skin abnormalities and limb defects on one side...

Coffin-Lowry syndrome is a rare genetic disorder characterized by mental retardation; abnormalities of the head and facial (craniofacial) area; large, soft hands with short, thin (tapered) fingers; short stature; and/or various skeletal abnormalit...

Cronkhite-Canada syndrome (CCS) is a very rare disease with symptoms that include loss of taste, intestinal polyps, hair loss, and nail growth problems. It is difficult to treat because of malabsorption that accompanies the polyps. CCS occurs prim...

Achard-Thiers syndrome is a rare disorder that occurs primarily in postmenopausal women and is characterized by type 2 (insulin-resistant) diabetes mellitus and signs of androgen excess. The exact cause of this syndrome is unknown....

Johanson-Blizzard syndrome (JBS) is an extremely rare genetic disorder that affects multiple organ systems of the body. Many symptoms are present at birth (congenital) or early childhood. The spectrum of potential features and physical findings as...

Ectrodactyly ectodermal dysplasia cleft lip/palate (EEC) syndrome is a rare genetic disorder. Symptoms can vary greatly from one person to another. Affected individuals often have abnormalities affecting the limbs including ectrodactyly, a conditi...

Epidermolysis bullosa (EB) is a genetic skin disorder characterized clinically by blister formation from mechanical trauma. There are four main types with additional sub-types identified. There is a spectrum of severity, and within each type, one ...

Cardiofaciocutaneous (CFC) syndrome is one of the RASopathies and is a rare genetic disorder is typically characterized by unusually sparse, brittle, curly hair; large head (macrocephaly); a prominent forehead and abnormal narrowing of the sides o...

Aarskog syndrome is an extremely rare genetic disorder marked by stunted growth that may not become obvious until the child is about three years of age, broad facial abnormalities, musculoskeletal and genital anomalies, and mild intellectual disab...

Peeling skin syndrome is a rare inherited skin disorder characterized by painless, continual, spontaneous skin peeling (exfoliation). Other findings may include blistering and/or reddening of the skin (erythema) and itching (pruritus). Peeling ski...

Hallermann-Streiff syndrome (HSS) is a rare genetic disorder that is primarily characterized by distinctive malformations of the skull and facial (craniofacial) region; sparse hair (hypotrichosis); eye abnormalities; dental defects; degenerative s...

Gangrene facts Gangrene refers to dead or dying body tissue(s) that occur because of inadequate blood supply. There are two major types of gangrene, wet gangrene and dry gangrene. Dry gangrene can result from con...

Congenital erythropoietic porphyria (CEP) is a very rare inherited metabolic disorder resulting from the deficient function of the enzyme uroporphyrinogen lll cosynthase (UROS), the fourth enzyme in the heme biosynthetic pathway. Due to the impair...

Trichotillomania (trik-o-til-o-MAY-nee-uh), also called hair-pulling disorder, is a mental disorder that involves recurrent, irresistible urges to pull out hair from your scalp, eyebrows or other areas of your body, despite trying to stop. ...

Hallermann-Streiff syndrome (HSS) is a rare genetic disorder that is primarily characterized by distinctive malformations of the skull and facial (craniofacial) region; sparse hair (hypotrichosis); eye abnormalities; dental defects; degenerative s...

Hallermann-Streiff syndrome (HSS) is a rare genetic disorder that is primarily characterized by distinctive malformations of the skull and facial (craniofacial) region; sparse hair (hypotrichosis); eye abnormalities; dental defects; degenerative s...

Epidermolysis bullosa (EB) is a genetic skin disorder characterized clinically by blister formation from mechanical trauma. There are four main types with additional sub-types identified. There is a spectrum of severity, and within each type, one ...

Hashimoto's thyroiditis is also known as Chronic Lymphocytic Thyroiditis, Hashimoto's Thyroiditis, and Chronic Autoimmune Thyroiditis. The thyroid gland gradually stops producing enough hormones to keep the body running normally as a result of Has...

Hay-Wells syndrome, also known as ankyloblepharon-ectodermal dysplasia-clefting (AEC) syndrome, is a rare inherited disorder that belongs to a group of disorders known as the ectodermal dysplasias. Major characteristics of Hay-Wells syndrome inclu...

Biotinidase deficiency (BTD) is a treatable, metabolic disorder that is the result of a low concentration, or complete lack, of the enzyme, biotinidase. Biotinidase deficiency is an inherited disorder in which the body is not able to properly proc...

Thyroid disease is particularly common in women of child-bearing age. As a result, it is no surprise that thyroid disease may complicate the course of pregnancy. Frequency varies among different populations and different c...

Keratosis follicularis spinulosa decalvans (KFSD) is a rare, inherited, skin disorder that affects men predominately and is characterized by hardening of the skin (keratosis) in several parts of the body. Most frequently, the face, neck, and forea...

Netherton syndrome is a rare hereditary disorder characterized by scaling skin, hair anomalies, increased susceptibility to atopic eczema (a skin condition that can result in dry, red and flaky skin), elevated IgE levels, and other related symptom...

Androgen insensitivity refers to an inability of the body to respond properly to male sex hormones (androgens) produced during pregnancy. This occurs because of a change (mutation) in a gene involved in the production of the protein inside cells t...

Incontinentia Pigmenti (IP) is a rare genetic dermatological disorder affecting the skin, hair, teeth, and central nervous system. Progressive skin changes occur in four stages, the first of which appear in early infancy or can be present at birth...

Hypomelanosis of Ito is a rare condition characterized by distinctive skin changes, in which areas of the body lack skin color (hypopigmentation). These skin changes may present as patches, streaks or spiral-shaped (whorled) areas. In many cases, ...

A keloid scar forms from abnormal healing, and usually develops in people 10 to 20 years old. A keloid, or keloid scar, is a kind of overgrown scar, or an overly aggressive healing response to a wound. It's a type of thick, irregul...

Keratosis follicularis, also known as Darier disease, is a rare, genetic skin disorder. Affected individuals develop skin lesions that consist of thickened, rough bumps (papules) or plaques that may also be greasy or have a brown or yellow crust. ...

Keratosis pilaris (KP) facts Keratosis pilaris is a very common, benign skin disorder that affects adolescents and adults. Keratosis pilaris causes numerous small, rough, tan or red little bumps around hair follicles on th...

Lichen Planus is a rare, recurrent, itchy rash or area of inflammatory eruptions (lesions) of unknown origin characterized by shiny reddish-purple spots on the skin and gray-white ones in the mouth. The disorder may present as itchy spots on the w...

Noonan syndrome is a common genetic disorder that is typically evident at birth (congenital). The disorder is characterized by a wide spectrum of symptoms and physical features that vary greatly in range and severity. In many affected individuals,...

Chromosome 3, Monosomy 3p is a rare chromosomal disorder in which the end (distal) portion of the short arm (p) of chromosome 3 is missing (deleted or monosomic). The range and severity of symptoms and findings may be variable. However, associated...

Hyperostosis Frontalis Interna is characterized by the thickening of the frontal bone of the skull. It is not clear that this disorder is actually rare. Some clinicians believe that it may be a common abnormality found in as many as 12 percent of ...

The Mucopolysaccharidoses (MPS Disorders) are a group of rare genetic disorders caused by the deficiency of one of the lysosomal enzymes, resulting in an inability to metabolize complex carbohydrates (mucopolysaccharides) into simpler molecules. H...

General DiscussionNeonatal lupus is a rare autoimmune disorder that is present at birth (congenital). Affected infants often develop a characteristic red rash or skin eruption. In addition, infants with neonatal lupus may develop liver di...

Neuropathic pain is a pain condition that’s usually chronic. It’s usually caused by chronic, progressive nerve disease, and it can also occur as the result of injury or infection. If you have chronic neuropathic pain, it can fl...

Epidermolysis bullosa (EB) is a genetic skin disorder characterized clinically by blister formation from mechanical trauma. There are four main types with additional sub-types identified. There is a spectrum of severity, and within each type, one ...

Oculocutaneous albinism (OCA) is a group of rare inherited disorders characterized by a reduced amount or complete lack of melanin pigment in the skin, hair, and eyes. These conditions are caused by mutations in specific genes that are necessary f...

Ovarian cysts facts Ovarian cysts are closed, sac-like structures within the ovary that are filled with a liquid or semisolid substance. Ovarian cysts form for numerous reasons. Pain in the abdomen or pelvis is t...

Bjornstad syndrome is an extremely rare inherited disorder characterized by the presence of abnormally flattened, twisted hair shafts (pili torti) and, in most cases, deafness (sensorineural hearing loss). Hearing loss typically affects both ears ...

Polycystic ovary syndrome  Polycystic ovary syndrome is a disorder involving infrequent, irregular or prolonged menstrual periods, and often excess male hormone (androgen) levels. The ovaries develop numerous small collections of flui...

Radiation sickness describes the harmful effects--acute, delayed, or chronic--produced by exposure to ionizing radiation. An observable effect due to radiation exposure becomes quite certain after a single dose of several hundred rads. As a rule, ...

Radiation sickness describes the harmful effects--acute, delayed, or chronic--produced by exposure to ionizing radiation. An observable effect due to radiation exposure becomes quite certain after a single dose of several hundred rads. As a rule, ...

Radiation sickness is damage to your body caused by a large dose of radiation often received over a short period of time (acute). The amount of radiation absorbed by the body — the absorbed dose — determines how sick you'll be. ...

Radiation sickness describes the harmful effects--acute, delayed, or chronic--produced by exposure to ionizing radiation. An observable effect due to radiation exposure becomes quite certain after a single dose of several hundred rads. As a rule, ...

Rothmund-Thomson syndrome (RTS) is a rare genetic disorder that can affect many parts of the body. The disorder is characterized by distinctive abnormalities of the skin, sparse hair, eyelashes and/or eyebrows, small stature, skeletal and dental a...

Rothmund-Thomson syndrome is a rare condition that affects many parts of the body, particularly the skin....

Aplasia Cutis Congenita is a rare disorder with a complicated pattern of inheritance. Babies are born with the absence of certain layer(s) of skin, most often on the scalp, but also on the trunk, and/or arms and legs. The affected area is typicall...

Psoriasis is an inflammatory disease of the skin that is estimated to affect about 2.2% of the adult population. Some people may have a genetic predisposition to psoriasis. The genes affected seem to be involved with control of the immune system. ...

Split hand/split foot malformation (SHFM) is a genetic disorder characterized by the complete or partial absence of some fingers or toes, often combined with clefts in the hands or feet. There may also be the appearance of webbing between fingers ...

Split hand/split foot malformation (SHFM) is a genetic disorder characterized by the complete or partial absence of some fingers or toes, often combined with clefts in the hands or feet. There may also be the appearance of webbing between fingers ...

Trichothiodystrophy is a hereditary disorder characterized by brittle hair, which may be accompanied by a variety of other manifestations. It is sometimes called PIBIDS, a term that refers to the association of Photosensitivity Ichthyosis, Brittle...

Tricho-dento-osseous (TDO) syndrome is an autosomal dominant genetic disorder that belongs to a group of diseases known as ectodermal dysplasias. Ectodermal dysplasias typically affect the hair, teeth, nails, and/or skin. TDO syndrome is character...

Grover's disease is a rare, transient skin disorder that consists of small, firm, raised red lesions, most often on the skin of the chest and back. Diagnosis of this disorder becomes apparent under microscopic examination when the loss of the "cem...

Tricho-dento-osseous (TDO) syndrome is an autosomal dominant genetic disorder that belongs to a group of diseases known as ectodermal dysplasias. Ectodermal dysplasias typically affect the hair, teeth, nails, and/or skin. TDO syndrome is character...

Trichorhinophalangeal syndrome type I (TRPS1) is an extremely rare inherited multisystem disorder. TRPS1 is characterized by thin, sparse scalp hair, unusual facial features, abnormalities of the fingers and/or toes, and multiple abnormalities of ...

Trichorhinophalangeal syndrome type II (TRPS2), also known as Langer-Giedion syndrome, is an extremely rare inherited multisystem disorder. TRPS2 is characterized by fine, thin hair; unusual facial features; progressive growth retardation resultin...

Trichorhinophalangeal syndrome type III (TRPS3), also known as Sugio-Kajii syndrome, is an extremely rare inherited multisystem disorder. TRPS3 is characterized by fine, thin light-colored hair; unusual facial features; abnormalities of the finger...

Trichotillomania (trik-o-til-o-MAY-nee-uh), also called hair-pulling disorder, is a mental disorder that involves recurrent, irresistible urges to pull out hair from your scalp, eyebrows or other areas of your body, despite trying to stop. ...

Porphyria cutanea tarda (PCT) is a type of porphyria in which affected individuals are sensitive to sunlight. Exposed skin shows abnormalities that range from slight fragility of the skin to persistent scarring and disfiguration. Due to fragility ...

Porphyria cutanea tarda (PCT) is a type of porphyria in which affected individuals are sensitive to sunlight. Exposed skin shows abnormalities that range from slight fragility of the skin to persistent scarring and disfiguration. Due to fragility ...

What is vitamin D? The "sunshine" vitamin is a hot topic. You may have recently found out that you are deficient or know someone who is. It's shocking for most people when they have never had a problem before and believe nothing has change...

Vitiligo is a disease in which the pigment cells of the skin, melanocytes, are destroyed in certain areas. Vitiligo results in depigmented, or white, patches of skin in any location on the body. Vitiligo can be focal and l...

Alopecia areata is a disorder characterized by loss of hair. Sometimes, this means simply a few bare patches on the scalp. In other cases, hair loss is more extensive. Although the exact cause is not known, this is thought to be an autoimmune diso...

Waardenburg syndrome is a genetic disorder that may be evident at birth (congenital). The range and severity of associated symptoms and findings may vary greatly from case to case. However, primary features often include distinctive facial abnorma...

Werner Syndrome is a rare progressive disorder that is characterized by the appearance of unusually accelerated aging (progeria). Although the disorder is typically recognized by the third or fourth decades of life, certain characteristic findings...