Diseases

Arachnoiditis

Arachnoiditis describes a pain disorder caused by the inflammation of the arachnoid, one of the membranes that surround and protect the nerves of the spinal cord. The arachnoid can become inflamed because of an irritation from chemicals, infection from bacteria or viruses, as the result of direct injury to the spine, chronic compression of spinal nerves, or complications from spinal surgery or other invasive spinal procedures. Inflammation can sometimes lead to the formation of scar tissue and adhesions, which cause the spinal nerves to "stick" together. If arachnoiditis begins to interfere with the function of one or more of these nerves, it can cause a number of symptoms, including numbness, tingling, and a characteristic stinging and burning pain in the lower back or legs. Adhesive arachnoiditis is the most severe form, characterized by debilitating, intractable neurogenic back and limb pain and a range of other neurological problems.[2]Arachnoiditis is difficult to treat and long-term outcomes are unpredictable. A regimen of pain management, physiotheraphy, exercise, and psychotheraphy is often recommended. Surgical treatment seem to offer only short-term relief.

Arakawa’s syndrome 2

Arakawa's syndrome II is an inborn error of metabolism, a genetic disorder that causes a deficiency of the enzyme tetrahydrofolate-methyltransferase; affected individuals cannot properly metabolize methylcobalamin, a type of Vitamin B12. It is also called Methionine synthase deficiency, Tetrahydrofolate-methyltransferase deficiency syndrome, and N5-methylhomocysteine transferase deficiency.

Arbovirosis

An infectious disease caused by an arbovirus. The word arbovirus is an acronym (ARthropod-BOrne virus). The word tibovirus (TIck-BOrne virus) is sometimes used to describe viruses transmitted by ticks, a superorder within the arthropods. The virus is transmitted by arthropods such as insects and ticks. Examples of arboviruses include Yellow Fever, Japanese encephalitis and tick-borne encephalitis.

The symptoms may vary depending on the type of virus involved. Symptoms of arbovirus infection generally occur 3–15 days after exposure to the virus and last 3 or 4 days. The most common clinical features of infection are fever, headache, and malaise, but encephalitis and hemorrhagic fever may also occur. The infection can lead to life-threatening brain inflammation.

AREDYLD

AREDYLD stands for acral renal ectodermal dysplasia lipoatrophic diabetes. A rare condition characterized by abnormalities of the extremities, teeth, hair, nail and kidney as well as lipoatrophic diabetes. It was characterized in 1983.

Arginase deficiency

Arginase deficiency is an inherited metabolic condition in which the body is unable to process arginine (a building block of protein). As a result, people affected by the condition have high levels of arginine in the blood and may also experience episodes of hyperammonemia (a buildup of ammonia in the blood). The features of arginase deficiency generally develop between ages one and three years.

A very rare urea cycle disorder caused by a deficiency of the enzyme (arginase) needed to convert ammonia to the urea which can then be removed in the urine. The condition leads to excess build-up of ammonia in the body which is toxic to the nervous system.

Argininosuccinic Aciduria

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 days of life. An infant withargininosuccinic aciduria may be lacking in energy (lethargic) or unwilling to eat, and have poorly controlled breathing rate or body temperature. Some babies with this disorder experience seizures or unusual body movements, or go into a coma. Complications from argininosuccinic aciduria may include developmental delay and intellectual disability. Progressive liver damage, skin lesions, and brittle hair may also be seen.

Occasionally, an individual may inherit a mild form of the disorder in which ammonia accumulates in the bloodstream only during periods of illness or other stress.

 

Arima syndrome

A rare disorder characterized mainly by eye and brain abnormalities.

Arnold Stickler Bourne syndrome

A very rare syndrome characterized by muscle problems in hands, mouth and pharynx, kidney anomalies and corneal crystals.

Arnold-Chiari Malformation

Arnold–Chiari malformation, is a condition affecting the brain. It consists of a downward displacement of the cerebellar tonsils through the foramen magnum (the opening at the base of the skull), sometimes causing non-communicating hydrocephalus as a result of obstruction of cerebrospinal fluid (CSF) outflow. The cerebrospinal fluid outflow is caused by phase difference in outflow and influx of blood in the vasculature of the brain.

Arnold-Chiari malformation- type 1

Chiari malformation type 1 is a structural abnormality of the cerebellum, the part of the brain that controls balance. It involves the extension of the lower part of the cerebellum into the foramen magnum (the large hole at the base of the skull which allows passage of the spinal cord), without involving the brainstem. Normally, only the spinal cord passes through this opening. This malformation is the most common type of Chiari malformation and may not cause any symptoms. Depending on the symptoms present and severity, some individuals may not require treatment while others may require pain medications or surgery.

Arnold-Chiari malformation- type 2

Chiari malformation type 2 (CM type II) is a type of Chiari malformation in which both the cerebellum and brain stem tissue extend into the foramen magnum (the hole at the skull base for passing of the spinal cord). This form is often accompanied by a type of spina bifida called myelomeningocele, and can also be accompanied by syringomyelia, hydrocephalus, or other abnormalities. In this malformation where the base of the brain enters into the upper spinal canal. The extent of the deformity is greater in type 2 than type 1 and hence the symptoms are more severe and are often associated with a myelomeningocele (opening of the spine and spinal cord). The term Arnold-Chiari malformation is technically specific to type II but may sometimes be used to describe other types of Chiari malformations.

Arnold-Chiari malformation- type 3

An extremely rare malformation where the base of the brain enters into the upper spinal canal. Type 3 involves the herniation of brain or brain stem tissue out of the back of the neck or head. The condition generally has a poor prognosis.

Arnold-Chiari malformation- type 4

Arnold-Chiari malformation is a rare malformation where the base of the brain enters into the upper spinal canal. Type 4 actually involves a lack of development of a portion of the base of the brain (cerebellum). The prognosis is very poor with death often occurring during infancy.

Aromatase deficiency

A congenital deficiency of the enzyme called aromatase which is needed to convert androgens to estrogens. Aromatase deficiency is resulting from insufficient production of the enzyme aromatase, which can result in inappropriate virilization of female fetuses and delayed puberty, as well as inappropriate virilization of the mother during pregnancy. Thus, it is a condition characterized by reduced levels of the female sex hormone estrogen and increased levels of the male sex hormone testosterone.

Females with aromatase deficiency have a typical female chromosome pattern (46,XX) but are born with external genitalia that do not appear clearly female or male (ambiguous genitalia). These individuals typically have normal internal reproductive organs, but develop ovarian cysts early in childhood, which impair the release of egg cells from the ovaries (ovulation). In adolescence, most affected females do not develop secondary sexual characteristics, such as breast growth and menstrual periods. They tend to develop acne and excessive body hair growth (hirsutism).

Men with this condition have a typical male chromosome pattern (46,XY) and are born with male external genitalia. Some men with this condition have decreased sex drive, abnormal sperm production, or testes that are small or undescended (cryptorchidism).

There are other features associated with aromatase deficiency that can affect both males and females. Affected individuals are abnormally tall because of excessive growth of long bones in the arms and legs. The abnormal bone growth results in slowed mineralization of bones (delayed bone age) and thinning of the bones (osteoporosis), which can lead to bone fractures with little trauma. Males and females with aromatase deficiency can have abnormally high blood sugar (hyperglycemia) because the body does not respond correctly to the hormone insulin. In addition, they can have excessive weight gain and a fatty liver.

Women who are pregnant with fetuses that have aromatase deficiency often experience mild symptoms of the disorder even though they themselves do not have the disorder. These women may develop hirsutism, acne, an enlarged clitoris (clitoromegaly), and a deep voice. These features can appear as early as 12 weeks of pregnancy and go away soon after delivery.

Aromatic amino acid decarboxylase deficiency

Aromatic l-amino acid decarboxylase (AADC) deficiency is an inherited condition that affects the way signals are passed between certain cells in the nervous system. In this disease in born error of metabolism involving the deficiency of an enzyme (aromatic L-amino acid decarboxylase) needed to process aromatic amino acids. This results in a deficiency of neurotransmitters such as dopamine and serotonin. The condition manifests as movement and neurological problems.

Arrhinia

Arrhinia is the congenital partial or complete absence of the nose at birth. It is an extremely rare condition, with few reported cases in the history of modern medicine. It is generally classified as a craniofacial abnormality.

Arrhythmogenic right ventricular dysplasia

Arrhythmogenic right ventricular dysplasia (ARVD, also known as arrhythmogenic right ventricular cardiomyopathy or ARVC)) is an inherited heart condition in which the muscle of the right ventricle of the heart is replaced by fat and/or scar tissue. It is characterized by hypokinetic areas involving the free wall of the right ventricle, with fibrofatty replacement of the right ventricular myocardium, with associated arrhythmias originating in the right ventricle. The condition is progressive and over time the right ventricle loses the ability to pump blood. Individuals with ARVD often develop abnormal heart rhythms known as arrhythmias, which can increase the risk of sudden cardiac arrest or death.

Arterial dysplasia

Venous aneurysms are rare and usually develop following trauma. This report describes an aneurysm of the internal jugular vein that was associated with dysplasia of the cervical arteries, in a patient with neurofibromatosis type 1 (NF1). The finding of neurofibromatous tissue in the wall of the aneurysm as well as in small veins, suggested that the venous aneurysm was caused by the neurofibromatous invasion.

Arterial tortuosity

Arterial tortuosity syndrome (ATS) is a disorder that affects connective tissue (a tissue that provides strength and flexibility to structures throughout the body, including blood vessels, skin, joints, and the gastrointestinal tract). It is characterized by blood vessel abnormalities, particularly abnormal twists and turns (tortuosity) of the blood vessels that carry blood from the heart to the rest of the body (the arteries). Other blood vessel abnormalities that may occur in this disorder include constriction (stenosis) and abnormal bulging (aneurysm) of vessels, as well as small clusters of enlarged blood vessels just under the skin (telangiectasia). Other features include:

  • Joints that are either loose and very flexible (hypermobile) or that have deformities limiting movement (contractures)
  • Soft and stretchable skin
  • Long, slender fingers and toes (arachnodactyly)
  • Curvature of the spine (scoliosis)
  • Sunken chest (pectus excavatum) or protruding chest (pectus carinatum)
  • Protrusion of organs through gaps in muscles (hernias)
  • Elongation of the intestines or pouches called diverticula in the intestinal walls

People with arterial tortuosity syndrome often look older than their age and have distinctive facial features. The cornea, which is the clear front covering of the eye, may be cone-shaped and abnormally thin (keratoconus). Arterial tortuosity syndrome is caused by alterations (mutations) in the SLC2A10 gene and is inherited in an autosomal recessive fashion. Aneurysms and focal stenoses are corrected with surgery. Many specialists may be needed for the best management of the disorder.

Arthrogryposis and ectodermal dysplasia

Arthrogryposis, an unusual type of ectodermal dysplasia, growth retardation of prenatal onset, and diabetes mellitus were all present in the proposita and are unlikely to have arisen all independently. The combination of at least some of these abnormalities may represent a distinct syndrome.

Arthrogryposis like disorder

It is a congenital (present at birth) contracture disorder that occurs solely among Yup'ik Eskimos in and around the Kuskokwim River delta region of southwest Alaska. Affected individuals usually, but not always, have congenital contractures of large joints (especially knees and/or elbows) and spinal, pelvic, and foot deformities. Other skeletal features have also been reported. Kuskokwim disease has been shown to be caused by mutations in the FKBP10 gene and is inherited in an autosomal recessive manner.