Diseases

Angelman syndrome

Angelman syndrome (AS) is a neurodevelopmental disorder characterized by severe intellectual and developmental disability, sleep disturbance, seizures, jerky movements (especially hand-flapping), frequent laughter or smiling, and usually a happy demeanor.

AS is a classic example of genomic imprinting in that it is caused by deletion or inactivation of genes on the maternally inherited chromosome 15 while the paternal copy, which may be of normal sequence, is imprinted and therefore silenced. The sister syndrome, Prader–Willi syndrome, is caused by a similar loss of paternally inherited genes and maternal imprinting.

AS is named after a British pediatrician, Harry Angelman, who first described the syndrome in 1965. An older, alternative term for AS, "happy puppet syndrome", is generally considered pejorative and stigmatizing so it is no longer the accepted term. People with AS are sometimes referred to as "angels", both because of the syndrome's name and because of their youthful, happy appearance.

Angiofollicular ganglionic hyperplasia

Angiofollicular ganglionic hyperplasia - hyaline-vascular type is a rare disorder characterized by a localized overgrowth of lymph node tissue which can form a benign tumor-like growth. There are two types of the disease: hyaline-vascular type or the plasma cell type which tends to have more severe symptoms. The hyaline-vascular type is usually asymptomatic but symptoms can be determined by the location and number of growths and the effect it can have on nearby tissue by pushing against it - e.g. squashing blood vessels.

There are two main forms: unicentric CD and multicentric CD. Unicentric CD is a "localized" condition that is generally confined to a single set of lymph nodes, while multicentric CD is a "systemic" disease that affects multiple sets of lymph nodes and other tissues throughout the body.

Angiofollicular lymph hyperplasia

Angiofollicular lymph hyperplasia (ALNH) is a rare disorder of the lymph system characterized by the development of benign tumors in lymph tissue anywhere in the body.

Angioimmunoblastic T-Cell Lymphoma

Angioimmunoblastic T-Cell lymphoma (AITL) is an aggressive T-cell lymphoma representing about 1-2% of all types of Non-Hodgkin's Lymphoma in the US. Elderly patients are more likely to have AITL, and it occurs more often in men than women. It has in the past been called Angioimmunoblastic Lymphadenopathy With Dysproteinemia (AILD). Initially was thought to represent an abnormal reaction of the immune system but it is now known to be a form of lymphoma. It is now a distinct entity under the newer WHO classification system.

AITL is a mature T-cell lymphoma of blood or lymph vessel immunoblasts characterized by a polymorphous lymph node infiltrate showing a marked increase in follicular dendritic cells (FDCs) and high endothelial venules (HEVs) and systemic involvement. It is also known as immunoblastic lymphadenopathy (Lukes-Collins Classification) and AILD-type (lymphogranulomatosis X) T-cell lymphoma (Kiel Classification).

Angioma serpiginosum- autosomal dominant

Angioma serpiginosum is an uncommon benign skin disorder characterized by asymptomatic clusters of nonpurpuric punctate erythematous lesions. The rash is asymptomatic but may lead to cosmetic problems and can be treated by laser therapy. Women are most commonly affected, and the disorder is most often sporadic, although rare families suggestive of autosomal dominant inheritance have been reported (Sandhu and Gupta, 2005). No male-to-male transmission has been described, but father-to-daughter transmissions are known. It has been suggested that the pattern of skin involvement may be due to cutaneous somatic mosaicism

Angioma serpiginosum- X-linked

Angioma serpiginosum is a rare benign congenital skin disorder characterized by nonpurpuric red punctate lesions seen histologically as capillary ectasias in the superficial papillary dermis. The lesions often follow Blaschko lines and are most commonly found in females (90%).

Angiomyomatous Hamartoma

A type of tumor that originates from blood vessel tissue. It is a rare type of tumor that tends to occur most often in lymph nodes in the inguinal (lower abdominal and groin) area.

Angiosarcoma of the breast

A rare type of cancer that starts in the lining of blood vessels in the breast. It is generally an aggressive tumor which often metastasizes.

Angiosarcoma of the liver

A rare type of cancer that starts in the lining of blood vessels in the liver. It is generally an aggressive tumor which often metastasizes. 

It is a rare fatal tumor, has been seen in workers intensively exposed to the gas vinyl chloride monomer (VCM) for prolonged periods while working in polyvinyl chloride (PVC) polymerization plants. It has also been associated with individuals exposed to arsenic-containing insecticides and Thorotrast. In dogs, hemangiosarcoma is relatively common, especially in larger breeds such as golden retrievers and Labrador retrievers.

Angiosarcoma of the scalp

Angiosarcoma of the scalp is a rare cancer which most commonly affects the elderly. This condition is characterized by bruise-like lesions that escalate to elevated, nodular, or ulcerated tumors. Extensive local growth is common and metastasis to regional lymph nodes and to the lungs may occur. 

Angiostrongyliasis

Angiostrongyliasis is an infection by a nematode from the Angiostrongylus genus of kidney and alimentary tract roundworms. For example, infection with Angiostrongylus cantonensis can occur after consuming raw Giant African land snails, Great Grey Slugs, or other mollusks.
In humans, Angiostrongylus is the most common cause of eosinophilic meningitis or meningoencephalitis. Frequently the infection will resolve without treatment or serious consequences, but in cases with a heavy load of parasites the infection can be so severe it can cause permanent damage to the CNS or death.

Angiotensin renin aldosterone hypertension

The rennin-angiotensin-aldosterone system (RAAS)  is involved in regulating blood volume and vascular resistance and an imbalance of any of these components can cause high blood pressure.

Aniridia

Aniridia is an eye disorder characterized by a complete or partial absence of the colored part of the eye (the iris). These iris abnormalities may cause the pupils to be abnormal or misshapen. Aniridia can cause reduction in the sharpness of vision (visual acuity) and increased sensitivity to light (photophobia).

People with aniridia can also have other eye problems. Increased pressure in the eye (glaucoma) typically appears in late childhood or early adolescence. Clouding of the lens of the eye (cataracts), occur in 50 percent to 85 percent of people with aniridia. In about 10 percent of affected people, the structures that carry information from the eyes to the brain (optic nerves) are underdeveloped. Individuals with aniridia may also have involuntary eye movements (nystagmus) or underdevelopment of the region at the back of the eye responsible for sharp central vision (foveal hypoplasia). Many of these eye problems contribute to progressive vision loss in affected individuals. The severity of symptoms is typically the same in both eyes. Rarely, people with aniridia have behavioral problems, developmental delay, and problems detecting odors.

Aniridia may occur either as an isolated eye abnormality or as part of the Wilms tumor-aniridia-genital anomalies-retardation (WAGR) syndrome, genitourinary anomlies and intellectual disability), or Gillespie syndrome (cerebellar ataxia).

Aniridia may be broadly divided into hereditary and sporadic forms. Hereditary aniridia is usually transmitted in an autosomal dominant manner (each offspring has a 50% chance of being affected), although rare autosomal recessive forms (such as Gillespie syndrome) have also been reported. Sporadic aniridia mutations may affect the WT1 region adjacent to the AN2 aniridia region, causing a kidney cancer called nephroblastoma (Wilms tumor). These patients often also have genitourinary abnormalities and intellectual disability (WAGR syndrome).

Aniridia absent patella

A rare genetic condition characterized by an abnormal or missing kneecap as well as the absence of the iris of the eye.

Aniridia cerebellar ataxia mental deficiency

Aniridia, cerebellar ataxia, mental deficiency (ACAMD) is an extremely rare inherited disorder that involves eye abnormalities, problems with balance and coordinating movements (ataxia), and mild to moderate intellectual disability.

Aniridia may be broadly divided into hereditary and sporadic forms. Hereditary aniridia is usually transmitted in an autosomal dominant manner (each offspring has a 50% chance of being affected), although rare autosomal recessive forms (such as Gillespie syndrome) have also been reported.

Gillespie syndrome is characterized by aniridia, which is the absence of the colored part of the eye (the iris). In most affected individuals, only part of the iris is missing (partial aniridia) in both eyes, but in some affected individuals, partial aniridia affects only one eye, or the entire iris is missing (complete aniridia) in one or both eyes. The absence of all or part of the iris can cause blurry vision (reduced visual acuity) and increased sensitivity to light (photophobia). Rapid, involuntary eye movements (nystagmus) can also occur in Gillespie syndrome.

The balance and movement problems in Gillespie syndrome result from underdevelopment (hypoplasia) of a part of the brain called the cerebellum. This abnormality can cause delayed development of motor skills such as walking. In addition, difficulty controlling the muscles in the mouth can lead to delayed speech development. The difficulties with coordination generally become noticeable in early childhood when the individual is learning these skills. People with Gillespie syndrome usually continue to have an unsteady gait and speech problems. However, the problems do not get worse over time, and in some cases they improve slightly.

Other features of Gillespie syndrome can include abnormalities in the bones of the spine (vertebrae) and malformations of the heart.
ACAMD is thought to be inherited as an autosomal recessive genetic trait and is extremely rare, with only 20 to 30 cases reported in the medical literature.

Anisakiasis

Anisakis is a genus of parasitic nematodes, which have life cycles involving fish and marine mammals. They are infective to humans and cause anisakiasis. People who produce immunoglobulin E in response to this parasite may subsequently have an allergic reaction, including anaphylaxis, after eating fish that have been infected with Anisakis species.

Ankyloglossia heterochromia clasped thumbs

An extremely rare inherited condition characterized by clasped thumbs (adducted thumb), different colored eyes and a tongue anomaly where the tongue has limited mobility due to the fact that it is excessively attached to the floor of the mouth.

Ankylosing spondylarthritis

Ankylosing spondylitis is an inflammatory disease that can cause some of the vertebrae in your spine to fuse together. This fusing makes the spine less flexible and can result in a hunched-forward posture. A severe case of ankylosing spondylitis can make it impossible for you to lift your head high enough to see forward.

Ankylosing spondylitis affects men more often than women. Signs and symptoms of ankylosing spondylitis typically begin in early adulthood. Inflammation also can occur in other parts of your body — such as your eyes and bowels.

Ankylosing spondylitis

Ankylosing spondylitis (AS) is an inflammatory disease that can cause some of the vertebrae in your spine to fuse together. This fusing makes the spine less flexible and can result in a hunched-forward posture. This is characterized by back pain and stiffness that typically appear in adolescence or early adulthood. Over time, back movement gradually becomes limited as the bones of the spine (vertebrae) fuse together. This progressive bony fusion is called ankylosis.If ribs are affected, it may be difficult to breathe deeply.

Ankylosing spondylitis affects men more often than women. Signs and symptoms of ankylosing spondylitis typically begin in early adulthood. Inflammation also can occur in other parts of your body — most commonly, your eyes.

The earliest symptoms of ankylosing spondylitis result from inflammation of the joints between the pelvic bones (the ilia) and the base of the spine (the sacrum). These joints are called sacroiliac joints, and inflammation of these joints is known as sacroiliitis. The inflammation gradually spreads to the joints between the vertebrae, causing a condition called spondylitis. Ankylosing spondylitis can involve other joints as well, including the shoulders, hips, and, less often, the knees. As the disease progresses, it can affect the joints between the spine and ribs, restricting movement of the chest and making it difficult to breathe deeply. People with advanced disease are also more prone to fractures of the vertebrae.

Ankylosing spondylitis affects the eyes in up to 40 percent of cases, leading to episodes of eye inflammation called acute iritis. Acute iritis causes eye pain and increased sensitivity to light (photophobia). Rarely, ankylosing spondylitis can also cause serious complications involving the heart, lungs, and nervous system

There is no cure for ankylosing spondylitis, but treatments can decrease your pain and lessen your symptoms.

Ankylosis of teeth

A rare genetic disorder where the teeth fuse to the bone which can prevent them from erupting.