Hereditary elliptocytosis (HE) refers to a group of inherited blood conditions where the red blood cells are abnormally shaped. Symptoms vary from very mild to severe and can include fatigue, shortness of breath, gallstones, and yellowing of the skin and eyes (jaundice).[1][2] Some people with this condition have an enlarged spleen. Hereditary elliptocytosis is caused by a genetic change…

Barth syndrome is a metabolic and neuromuscular disorder, occurring almost exclusively in males, that primarily affects the heart, immune system, muscles, and growth. It typically becomes apparent during infancy or early childhood, but the age of onset, associated symptoms and findings, and disease course varies considerably among affected individuals. The main characteristics of the condition include abnormalities of…

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs. Orpha Number: 1576 Definition Infantile bilateral striatal necrosis (IBSN) comprises several syndromes of bilateral symmetric spongy degeneration of the caudate nucleaus, putamen and globus pallidus characterized by developmental regression, choreoathetosis and dystonia progressing to spastic quadriparesis. IBSN…

Multifocal motor neuropathy (MMN) causes damage to the nerves in the arms and legs. Nerve damage begins in adulthood and slowly gets worse over time. One side of the body may be more affected than the other. Symptoms of MMN may include weakness in the hands and lower arms; cramping; involuntary contractions or twitching; wrist…

Coffin-Lowry syndrome is a genetic condition that affects many parts of the body. The signs and symptoms and severity vary from person to person; however, males are typically more severely affected than females. Signs and symptoms may include distinct facial findings, short stature, microcephaly, kyphoscoliosis, other skeletal abnormalities, stimulus-induced drop episodes, intellectual disability and delayed development. Mutations…

Congenital dyserythropoietic anemia is a hereditary disease that affects the production of red blood cells (erythropoiesis) and is characterized by anemia and problems in various organs. The signs and symptoms may include fatigue, weakness, pale skin, yellowing of the skin and eyes (jaundice), larger-than-normal liver and spleen (hepatosplenomegaly), and problems of the heart.[1] There are…

Hypohidrotic ectodermal dysplasia (HED) is a genetic skin disease. Common symptoms include sparse scalp and body hair, reduced ability to sweat, and missing teeth. HED is caused by mutations in the EDA, EDAR, or EDARADD genes. It may be inherited in an X-linked recessive, autosomal recessive, or autosomal dominant manner depending on the genetic cause of the condition. The X-linked form is the…

Neurofibromatosis type 2 (NF2) is a disorder characterized by the growth of noncancerous tumors of the nervous system. Childhood symptoms include skin growths and eye findings. Almost all people with NF2 develop vestibular schwannomas affecting both ears by age 30. Other tumors of the central nervous system (the brain and spinal cord), skin and eye are also…

Multiple epiphyseal dysplasia (MED) is a group of disorders of cartilage and bone development, primarily affecting the ends of the long bones in the arms and legs (epiphyses). There are two types of MED, which are distinguished by their patterns of inheritance autosomal dominant and autosomal recessive. Signs and symptoms may include joint pain in…

Oculocutaneous albinism type 2 is a genetic condition that affects the coloring (pigmentation) of the skin, hair, and eyes. Affected individuals typically have very fair skin and white or light-colored hair. Long-term sun exposure greatly increases the risk of skin damage and skin cancers, including an aggressive form of skin cancer called melanoma, in people with…

Limb-girdle muscular dystrophy is a group of disorders which affect the voluntary muscles around the hips and shoulders. The conditions are progressive, leading to a loss of muscle strength and bulk over a number of years. Onset may occur in childhood, adolescence, young adulthood, or even later. Males and females are affected in equal numbers.[1] Most…

Argininosuccinic aciduria is an inherited disorder that causes ammonia to accumulate in the blood. Ammonia, which is formed when proteins are broken down in the body, is toxic if the levels become too high. The nervous system is especially sensitive to the effects of excess ammonia. Argininosuccinic aciduria usually becomes evident in the first few…

Hypereosinophilic syndrome (HES) refers to a rare group of conditions that are associated with persistent eosinophilia with evidence of organ involvement. Signs and symptoms vary significantly based on which parts of the body are affected. Although any organ system can be involved in HES, the heart, central nervous system, skin, and respiratory tract are the…

Smith-Magenis syndrome (SMS) is a developmental disorder that affects many parts of the body. The major features of this condition include mild to moderate intellectual disability, delayed speech and language skills, distinctive facial features, sleep disturbances, and behavioral problems. Most people with SMS have a deletion of genetic material in each cell from a specific region…

Myasthenia gravis (MG) is a chronic autoimmune neuromuscular disease characterized by weakness of the skeletal muscles. Common symptoms include weakness of the muscles that control the eye and eyelid, facial expressions, chewing, talking, and swallowing. Weakness tends to increase during periods of activity and improve after periods of rest. The condition results from a defect in…

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a neurological disorder that causes progressive weakness and impaired sensory function in the legs and arms. Symptoms often include tingling or numbness (first in the toes and fingers), weakness of the arms and legs, loss of deep tendon reflexes, fatigue, and abnormal sensations.[1] Other symptoms may include pain, difficulty…

Hypochondroplasia is a form of skeletal disease characterized by very short stature. Hypochondroplasia is similar to achondroplasia, but the features tend to be milder. People with hypochondroplasia usually have very short stature, large head, accentuated lordosis, short arms and legs, and broad, short hands and feet. Other features include a limited range of motion in…

ADNP syndrome, also known as Helsmoortel-van der Aa syndrome, is a complex neuro-developmental disorder that affects the brain and many other areas and functions of the body. ADNP syndrome can affect muscle tone, feeding, growth, hearing, vision, sleep, fine and gross motor skills, as well as the immune system, heart, endocrine system, and gastrointestinal tract.[1]…

Frontotemporal dementias (FTDs) are a group of neurodegenerative disorders associated with shrinking of the frontal and temporal anterior lobes of the brain.[1] Symptoms include marked changes in social behavior and personality, and/or problems with language. People with behavior changes may have disinhibition (with socially inappropriate behavior), apathy and loss of empathy, hyperorality (eating excessive amounts of…

Early-onset, autosomal dominant Alzheimer disease is a form of Alzheimer disease (AD) that develops before the age of 65. It is diagnosed in families that have more than one member with AD (usually multiple persons in more than one generation) in which the age of onset is consistently before age 60 and often between the ages…

Factor V deficiency is an inherited bleeding disorder that prevents blood clots from forming properly.[1] This disorder is caused by mutations in the F5 gene, which leads to a deficiency of a protein called coagulation factor V.[2] The reduced amount of factor V may lead to nosebleeds, easy bruising, and excessive bleeding following surgery or…

Optic atrophy 1, also known as optic atrophy type 1 is a disease that affects the optic nerve. The optic nerve carries signals from the eye to the brain about what is seen. People with optic atrophy type 1 have an optic nerve that has lost some tissue (atrophy). This atrophy causes the optic nerve…

Familial Mediterranean fever is an inherited condition characterized by recurrent episodes of painful inflammation in the abdomen, chest, or joints. These episodes are often accompanied by fever and sometimes a rash or headache. Occasionally inflammation may occur in other parts of the body, such as the heart; the membrane surrounding the brain and spinal cord;…

Idiopathic intracranial hypertension (IIH), formerly known as pseudotumor cerebri, is a condition that affects the brain. Pseudotumor cerebri literally translates to “false brain tumor.” This term was used because symptoms of IIH resemble those of brain tumors depsite no tumor being present. Symptoms of IIH may include severe headache, nausea and vomiting, altered vision, and pulsating…

Brugada syndrome is a heart condition that causes a disruption of the normal rhythm in the heart’s lower chambers (ventricular arrhythmia). Signs and symptoms usually develop in adulthood but the diagnosis may be made at any age.[1] Symptoms and complications often occur during rest or sleep, and may include fainting, seizures, difficulty breathing, or sudden…

Psoriatic juvenile idiopathic arthritis is a subtype of juvenile idiopathic arthritis that is characterized by both arthritis and psoriasis. Other signs and symptoms may include dactylitis (inflammation and swelling of an entire finger or toe); nail pitting or splitting; and eye problems. Although the underlying cause of psoriatic juvenile idiopathic arthritis is currently unknown (idiopathic),…

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs. Orpha Number: 251899 Definition Choroid plexus carcinoma is a rare and highly aggressive malignant type of choroid plexus tumor (see this term) occurring almost exclusively in children, presenting with cerebrospinal fluid obstruction in the lateral ventricles (most…

Neuroblastoma is a tumor that develops from neuroblasts (immature nerve tissue) in an infant or child, usually before the age of 5. It most often develops in infancy and may be diagnosed in the first month of life. The tumor most often develops in the adrenal gland, but may develop in the neck, chest, or…

Usher syndrome is a genetic disorder characterized by sensorineural hearing loss or deafness and progressive vision loss due to retinitis pigmentosa. Sensorineural hearing means it is caused by abnormalities of the inner ear. Retinitis pigmentosa is an eye disease that affects the layer of light-sensitive tissue at the back of the eye (the retina). Vision loss…

Cystinuria is an inherited condition characterized by a buildup of the amino acid, cystine, in the kidneys and bladder. This leads to the formation of cystine crystals and/or stones which may block the urinary tract. Signs and symptoms of the condition are related to the presence of stones and may include nausea, hematuria, flank pain,…

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs. Orpha Number: 517 Definition A rare acute myeloid leukemia disorder characterized by increased blast cells (myeloblasts, monoblast, and/or promonoblasts), representing more than 20% of the total bone marrow (BM) or peripheral blood differential counts, with 20-80% of…

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs. Orpha Number: 79400 Definition Localized epidermolysis bullosa simplex, formerly known as EBS, Weber-Cockayne, is a basal subtype of epidermolysis bullosa simplex (EBS, see this term). The disease is characterized by blisters occurring mainly on the palms and…

Hereditary fructose intolerance (HFI) is a metabolic disease caused by the absence of an enzyme called aldolase B. In people with HFI, ingestion of fructose (fruit sugar) and sucrose (cane or beet sugar, table sugar) causes severe hypoglycemia (low blood sugar) and the build up of dangerous substances in the liver. HFI may be relatively mild or a…

Alpha mannosidosis  is a lysosomal storage disorder, a form of inborn metabolic disease. It is characterized by intellectual disability, hearing loss, ataxia, skeletal abnormalities, and coarse facial features.Signs and symptoms vary, but often include mild to moderate intellectual disability, hearing loss, weakened immune system, distinctive facial features, and cerebellar disorders (e.g., ataxia). Symptoms slowly worsen over time….

Sjogren-Larsson syndrome (SLS) is an inborn error of lipid metabolism, characterized by congenital ichthyosis (dry, scaly skin), intellectual disability, and spasticity (stiffness and involuntary muscle spasms). The syndrome is caused by mutations in the gene called FADH (fatty aldehyde dehydrogenase) and is inherited in an autosomal recessive fashion. Treatment is symptomatic.[1][2]

Pulmonary arterial hypertension (PAH) affects the heart and lungs. It is characterized by abnormally high blood pressure (hypertension) in the pulmonary artery, the blood vessel that carries blood from the heart to the lungs. Symptoms include shortness of breath (dyspnea) during exercise and fainting spells. The symptoms tend to get worse over time and may include dizziness, swelling…

Hereditary hemorrhagic telangiectasia (HHT) is an inherited disorder of the blood vessels that can cause excessive bleeding. People with HHT can develop abnormal blood vessels called arteriovenous malformations (AVMs) in several areas of the body. AVMs on the skin are called telangiectasias. AVMs can also develop in other parts of the body, including the brain, lungs,…

Tetrahydrobiopterin (BH4) deficiency causes the body to build up an abnormally high level of phenylalanine, one of the building blocks of proteins. In addition, BH4 deficiency leads to low levels of certain neurotransmitters, chemical messengers that control many body functions. Symptoms can range from very mild to severe. Babies with BH4 deficiency appear normal at birth…

Dermatitis herpetiformis is a rare, chronic, skin disorder characterized by groups of severely itchy blisters and raised skin lesions. These are more common on the knees, elbows, buttocks and shoulder blades. The slow onset of symptoms usually begins during adulthood, but children can also be affected. Other symptoms may include fluid-filled sores; red lesions that resemble hives;…

Klatskin tumors are are a type of cholangiocarcinoma that begins in an area called the hilum, where the left and right bile ducts join and leave the liver. It is the most common type of cholangiocarcinoma, accounting for more than half of all cases.[1][2][3][4] Symptoms usually don’t present until advanced stages of disease, when jaundice…

Fukuyama type muscular dystrophy (FCMD) affects the muscles and brain, causing muscle damage that gets worse over time. There are mild, typical, and severe forms of FCMD. Symptoms begin at birth and include a poor suck, weak cry, and floppiness. Later symptoms include severe speech delay, intellectual disability, seizures, and visual impairment. Over time, muscle…

Van der Woude syndrome is a condition that affects the development of the face. Many people with this disorder are born with a cleft lip and/or a cleft palate. Affected individuals usually have depressions (pits) near the center of the lower lip, which may appear moist due to the presence of salivary and mucous glands in…

Factor XI deficiency is a bleeding disorder that interferes with the body’s clotting process. As a result, people affected by this condition may have difficulty stopping the flow of blood following dental extractions, trauma or surgery. Women with factor XI deficiency may also experience heavy menstrual periods or heavy postpartum bleeding. Within affected people and…

Congenital muscular dystrophy type 1A (MDC1A) belongs to a group of neuromuscular disorders that beings at birth or infancy and is characterized mainly by hypotonia, muscle weakness and muscle wasting. Other signs and symptoms include rigidity of the spine; scoliosis; and delayed, limited motor development, with most individuals needing assistive devices for mobility. Respiratory problems, feeding disorders and seizures may…

Darier disease is a skin condition characterized by wart-like blemishes on the body. The blemishes are usually yellowish in color, hard to the touch, mildly greasy, and can emit a strong odor. The most common sites for blemishes are the scalp, forehead, upper arms, chest, back, knees, elbows, and behind the ear. The mucous membranes…

Alpha-1 antitrypsin deficiency (AATD) is an inherited disease that causes an increased risk of having chronic obstructive pulmonary disease (COPD), liver disease, skin problems (panniculitis), and inflammation of the blood vessels (vasculitis).[1][2][3] Lung (pulmonary) problems almost always occur in adults, whereas liver and skin problems may occur in adults and children.[2] The age symptoms begin and severity…

Systemic mastocytosis (SM) is a form of mastocytosis in which mast cells accumulate in internal tissues and organs such as the liver, spleen, bone marrow, and small intestines. It is typically diagnosed in adults. Signs and symptoms vary based on which parts of the body are affected. The disorder is usually caused by somatic changes (mutations) in…

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs. Orpha Number: 514 Definition Acute monoblastic leukemia (AML-M5), is one of the most common subtypes of acute myeloid leukemia (AML; see this term) that is either comprised of more than 80% of monoblasts (AML-M5a) or 30-80% monoblasts…

Autosomal dominant tubulointerstitial kidney disease (ADTKD) is a group of genetic kidney diseases that cause progressive loss of kidney function. Signs and symptoms of all forms of ADTKD include slowly worsening kidney disease (often becoming apparent by the teenage years) that ultimately results in end-stage kidney disease at some time between the ages of 20 and…

Alopecia universalis (AU) is a condition characterized by the complete loss of hair on the scalp and body. It is an advanced form of alopecia areata, a condition that causes round patches of hair loss.[1] Although the exact cause of AU is unknown, it is thought to be an autoimmune condition in which the person’s…

Mucopolysaccharidosis type I (MPS I) is a condition that affects many parts of the body. It is a progressively debilitating disorder; however, the rate of progression varies among affected individuals. MPS I is caused by mutations in the IDUA gene. These mutations lead to reduced levels or the complete lack of the IDUA enzyme. Without the proper amount…

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Spinocerebellar ataxia 3 (SCA3) is a rare, inherited form of ataxia. Signs and symptoms may begin between childhood and late adulthood and vary greatly. Symptoms may include slowly progressive clumsiness in the arms and legs; a manner of walking (gait) that may be mistaken for drunkenness; difficulty speaking and swallowing; impaired eye movements or vision; and lower…

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired disorder that leads to the premature death and impaired production of blood cells. It can occur at any age, but is usually diagnosed in young adulthood. People with PNH have recurring episodes of symptoms due to hemolysis, which may be triggered by stresses on the body such as…

Retinitis pigmentosa (RP) is a group of inherited eye diseases that affect the light-sensitive part of the eye (retina). RP causes cells in the retina to die, causing progressive vision loss. The first sign of RP usually is night blindness. As the condition progresses, affected individuals develop tunnel vision (loss of peripheral vision), and eventually…

Chromosome 18p tetrasomy is a chromosomal disorder that affects many parts of the body. It occurs when the short arm of chromosome 18 (18p) appears four times (tetrasomy) rather than the normal two times in cells of the body.[1][2] The symptoms of chromosomy 18p tetrasomy vary from case to case but may include abnormalities of the head…

Oculopharyngeal muscular dystrophy (OPMD) is a genetic disorder characterized by slowly progressing muscle disease (myopathy) affecting the muscles of the upper eyelids and the throat. Onset is typically during adulthood, most often between 40 and 60 years of age. Symptoms may include: eyelid drooping (ptosis), arm and leg weakness, and difficulty swallowing (dysphagia).[1] There are two types…

Ovarian cancer is a form of cancer that occurs due to abnormal and uncontrolled cell growth in the ovaries. Many people with early ovarian cancer have no signs or symptoms of the condition. When present, symptoms are often nonspecific and blamed on other, more common conditions. Most cases of ovarian cancer occur sporadically in people…

Usher syndrome is a genetic disorder characterized by sensorineural hearing loss or deafness and progressive vision loss due to retinitis pigmentosa. Sensorineural hearing means it is caused by abnormalities of the inner ear. Retinitis pigmentosa is an eye disease that affects the layer of light-sensitive tissue at the back of the eye (the retina). Vision loss…

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs. Orpha Number: 331206 Definition Severe combined immunodeficiency due to complete RAG1/2 deficiency is a rare, genetic T-Bsevere combined immunodeficiency disorder due to null mutations in recombination activating gene (RAG) 1 and/or RAG2 resulting in less than 1%…

Cystinosis is a genetic condition present from birth that leads to the build-up of cystine crystals in the body. This can impact all the organs and tissues, but mainly affects the kidneys and eyes. There are three types of cystinosis based on the age that symptoms start. The most common is the type that starts…

Syringomyelia is a condition in which a cyst, called a syrinx, forms within the spinal cord. This cyst expands and elongates over time, destroying the center of the spinal cord which can result in pain, weakness, stiffness in the back, shoulders, arms, or legs, headaches, and insensitivity to temperature (especially in the hands). Symptoms vary…

Acquired hemophilia is a bleeding disorder that interferes with the body’s blood clotting process. Although the condition can affect people of all ages, it generally occurs in older people (the median age of diagnosis is between 60 and 67 years). Signs and symptoms include prolonged bleeding, frequent nosebleeds, bruising throughout the body, solid swellings of…

X-linked adrenoleukodystrophy (X-ALD) is a genetic disease that affects the nervous system and the adrenal glands (small glands located on top of each kidney). People with this disease often have progressive loss of the fatty covering (myelin) that surrounds the nerves in the brain and spinal cord. They may also have a shortage of certain…

Facioscapulohumeral muscular dystrophy is a disorder characterized by muscle weakness and wasting (atrophy). This condition gets its name from the areas of the body that are affected most often: muscles in the face (facio-), around the shoulder blades (scapulo-), and in the upper arms (humeral). The signs and symptoms of facioscapulohumeral muscular dystrophy usually appear…

Supravalvular aortic stenosis (SVAS) is a type of heart defect that develops before birth. It is characterized by a narrowing (stenosis) of the section of the aorta just above the valve that connects the aorta to the heart (aortic valve). The severity of SVAS varies from person to person; some individuals may die in infancy…

Fetal and neonatal alloimmune thrombocytopenia (NAIT) is a blood disorder that affects pregnant women and their babies.[1] NAIT was first reported in the literature in 1953 and is estimated to occur in as many as 1 in 1200 live births.[2] NAIT results in the destruction of platelets in the fetus or infant due to a…

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs. Orpha Number: 36234 Definition Bacterial toxic shock syndrome (TSS) is a potentially fatal, acute disease characterized by a sudden onset of high fever along with nausea, myalgia, vomiting and multisystem organ involvement, potentially leading to shock and…

Budd-Chiari syndrome is a rare disorder characterized by obstruction of the veins of the liver that carry the blood flow from the liver.[1][2] When the blood flow out of the liver is impeded, blood backs up in the liver, causing it to enlarge (hepatomegaly). The spleen may also enlarge (splenomegaly). This backup of blood increases blood…

Friedreich ataxia is an inherited condition that affects the nervous system and causes movement problems. People with this condition develop impaired muscle coordination (ataxia) that worsens over time. Other features include the gradual loss of strength and sensation in the arms and legs, muscle stiffness (spasticity), and impaired speech. Many individuals have a form of heart…

Ectodermal dysplasias (ED) are a group of more than 180 disorders that affect the outer layer of tissue of the embryo (ectoderm) that helps make up the skin, sweat glands, hair, teeth, and nails. Symptoms of ED can range from mild to severe and may include teeth abnormalities; brittle, sparse or absent hair; abnormal fingernails;…

Congenital adrenal hyperplasia (CAH) refers to a group of genetic conditions that affect the adrenal glands. These glands sit on top of the kidneys and are responsible for releasing various types of hormones that the body needs to function. Affected people lack an enzyme the adrenal glands need to make one or more of these…

Spinal muscular atrophy (SMA) is a group of genetic neuromuscular disorders that affect the nerve cells that control voluntary muscles (motor neurons). The loss of motor neurons causes progressive muscle weakness and loss of movement due to muscle wasting (atrophy). The severity of the symptoms, the age at which symptoms, begin, and genetic cause varies…

Rett syndrome is a progressive, neuro-developmental condition that primarily affects girls. Affected girls appear to have normal psychomotor development during the first 6 to 18 months of life, followed by a developmental “plateau,” and then rapid regression in language and motor skills. Additional signs and symptoms may include repetitive, stereotypic hand movements; fits of screaming…

Focal segmental glomerulosclerosis (FSGS) is a type of kidney disorder. It is characterized by scar tissue that forms in some of the glomeruli in the kidney.[1] FSGS may cause non-specific signs and symptoms, including protein in the urine, elevated levels of creatinine, and swelling.[2][3] In many cases the cause of FSGS can not be determined. Some…

Immune thrombocytopenic purpura (ITP) is a bleeding disorder characterized by too few platelets in the blood. This is because platelets are being destroyed by the immune system. Symptoms may include bruising, nosebleed or bleeding in the mouth, bleeding into the skin, and abnormally heavy menstruation. With treatment, the chance of remission (a symptom-free period) is…

Lennox-Gastaut syndrome is a form of severe epilepsy that begins in childhood. It is characterized by multiple types of seizures and intellectual disability.[1] This condition can be caused by brain malformations, perinatal asphyxia (lack of oxygen), severe head injury, central nervous system infection and inherited degenerative or metabolic conditions. In about one-third of cases, no…

Autoimmune hemolytic anemia (AIHA) occurs when your immune system makes antibodies that attack your red blood cells. This causes a drop in the number of red blood cells, leading to hemolytic anemia.[1][2][3][4] Symptoms may include unusual weakness and fatigue with tachycardia and breathing difficulties, jaundice, dark urine and/or splenomegaly. AIHA can be primary (idiopathic) or result from…

IgA nephropathy is a kidney disorder that occurs when IgA (immunoglobulin A), a protein that helps the body fight infections, settles in the kidneys. IgA nephropathy can occur at any age, even in childhood. After many years, deposits of IgA may cause the kidneys to leak blood and sometimes protein in the urine. In the early…

Narcolepsy is a chronic brain disorder that involves poor control of sleep-wake cycles. People with narcolepsy have episodes of extreme daytime sleepiness and sudden, irresistible bouts of sleep (called “sleep attacks”) that can occur at any time, and may last from seconds or minutes. Other signs and symptoms may include cataplexy (a sudden loss of…