Diseases

Acanthocheilonemiasis

Acanthocheilonemiasis is a rare tropical infectious disease caused by a parasite known as Acanthocheilonema perstans. It can cause skin rashes,abdominal and chest pains, muscle and joint pains, neurologic disorders and skin lumps. It is mainly found in Africa. The parasite is transmitted through the bite of small flies. Studies show that there are elevated levels of white blood cells.

Acanthocytosis

Acanthocytes (from the Greek word acantha, which means thorn), or spur cells, are spiculated red cells with a few projections of varying size and surface distribution. The cells appear contracted, dense, and irregular. The morphology of acanthocytes in these various conditions is similar, but the pathogenesis and clinical context often greatly differ. In general, the formation of acanthocytes depends on alteration of the lipid composition and fluidity of the red cell membrane. Acanthocytosis is a red cell phenotype associated with various underlying conditions. The most frequent and most significant conditions include abetalipoproteinemia

Acanthokeratodermia

An uncommon skin condition involving excessive growth of the horny part of the skin on the palms of the hands and soles of the feet. Patients also suffer thickening of the nails.

Acanthoma

An acanthoma is a small, reddish bump that usually develops on the skin of an older adult. There are several types of acanthoma, including "acantholytic", "epidermolytic", "clear cell", and "melanoacanthoma". Though most individuals have only one acanthoma, there have been rare reports of individuals who have developed many. Acanthomas are not considered dangerous and do not require treatment, but they may be removed for cosmetic reasons or to relieve any associated symptoms.

Acanthosis nigricans

Acanthosis nigricans (AN) is a skin disorder in which there is darker, thick, velvety skin in body folds and creases. This condition usually appears slowly and doesn't cause any symptoms other than skin changes. Eventually, dark, velvety skin with very visible markings and creases appears in the armpits, groin and neck folds, and over the joints of the fingers and toes. Less commonly, the lips, palms, soles of the feet, or other areas may be affected.

Acardia

Acardia is a very rare, serious malformation that occurs almost exclusively in monozygous twins (twins developing from a single egg). This condition results from artery to artery connections in the placenta causing a physically normal fetus to circulate blood for both itself and a severely malformed fetus whose heart regresses or is overtaken by the pump twin's heart.

Acatalasemia

Acatalasemia is a congenital disorder resulting from a deficiency in erythrocyte catalase, an enzyme responsible for the breakdown of hydrogen peroxide. The disorder is very rare in the general population with an estimated prevalence of 1 in 31250. The disorder is usually asymptomatic but may be associated with oral ulcerations and gangrene, or diabetes mellitus and atherosclerosis in certain populations. Transmission is autosomal recessive. It is often characterized by infection of the gums.

Accessory deep peroneal nerve

Accessory deep peroneal nerv is an extra nerve in the leg that some people have. The accessory peroneal nerve branches off from the peroneal nerve and provides additional innervations for the foot muscles. The anomaly poses no problems and is asymptomatic but may be noticed if nerve conduction tests are done on the leg nerves.

Accessory navicular bone

An accessory navicular bone is a bone of the foot that occasionally develops abnormally in front of the ankle towards the inside of the foot. This bone may be present in approximately 2.5% of the general population and is usually asymptomatic. When it is symptomatic, surgery may be necessary.

Accessory pancreas

Accessory pancreas is a rare condition in which small groups of pancreatic cells are separate from the pancreas. They may occur in the mesentery of the small intestine, the wall of the duodenum, the upper part of the jejunum, or more rarely, in the wall of the stomach, ileum, gallbladder or spleen. The condition was first described by Klob in 1859.

Accutane embryopathy

Accutane embryopathy is a rare disorder and it is also called as Fetal Retinoid Syndrome. Accutane Embryopathy is a characteristic pattern of mental and physical birth defects that results from maternal use of retinoids, the synthetic vitamin Aderivative during pregnancy. The most well known retinoid is Isotretinoin (Accutane), a drug used to treat severe nodular acne. Birth defects associated with fetal retinoid syndrome include: hydrocephalus, microcephaly, intellectual disabilities, ear and eye abnormalities, cleft palate and other facial differences, and heart defects. Isotretinoin can cause these birth defects in the early weeks of pregnancy, even before a woman knows that she is pregnant.

Aceruloplasminemia

Aceruloplasminemia is an autosomal recessive disorder characterized by progressive neurodegeneration of the retina and basal ganglia and diabetes mellitus. Iron accumulates in the pancreas, liver and brain. Iron accumulation in the brain results in neurological problems that generally appear in adulthood and worsen over time. Accumulation in the eye may lead to retinal degeneration. Signs and symptoms begin in adulthood. People with this disorder tend to develop anemia and diabetes in their 20's. As the condition progresses, movement problems are common, such as tremors, chorea, ataxia, eyelid twitching, and grimacing. Some experience psychiatric problems and dementia in their 40's and 50's. Eye examination may reveal changes in the retina, but these changes typically do not affect vision.

Acetyl-coa acetyltransferase 2 deficiency

Acetyl-coa acetyltransferase 2 deficiency is a rare disorder where a genetic anomaly results in a deficiency of a particular enzyme (Acetyl-coa acetyltransferase 2) which is associated with mental retardation and reduced muscle tone. The enzyme is involved in lipid metabolism.

Achalasia

Achalasia is a failure of smooth muscle fibers to relax, which can cause a sphincter to remain closed and fail to open when needed. Without a modifier, "achalasia" usually refers to achalasia of the esophagus, which is also called esophageal achalasia, achalasia cardiae,cardiospasm, and esophageal aperistalsis. Achalasia can happen at various points along the gastrointestinal tract; achalasia of the rectum, for instance, in Hirschsprung's disease.

Esophageal achalasia is an esophageal motility disorder involving the smooth muscle layer of the esophagus and the lower esophageal sphincter (LES). It is characterized by incomplete LES relaxation, increased LES tone, and lack of peristalsis of the esophagus (inability of smooth muscle to move food down the esophagus) in the absence of other explanations like cancer or fibrosis.

Achalasia is characterized by difficulty in swallowing, regurgitation, and sometimes chest pain. Diagnosis is reached with esophageal manometry and barium swallow radiographic studies. Various treatments are available, although none cures the condition. Certain medications or Botox may be used in some cases, but more permanent relief is brought by esophageal dilatation and surgical cleaving of the muscle (Heller myotomy).

The most common form is primary achalasia, which has no known underlying cause. It is due to the failure of distal esophageal inhibitory neurons. However, a small proportion occurs secondary to other conditions, such as esophageal cancer or Chagas disease (an infectious disease common in South America). Achalasia affects about one person in 100,000 per year. There is no gender predominance for the occurrence of disease

Achalasia Addisonianism Alacrimia syndrome

It is a rare autosomal recessive congenital disorder. In most cases, there is no family history of it and only about 70 cases reported worldwide. It is an inherited condition characterized by three specific features: achalasia, Addison disease, and alacrima. Achalasia is a disorder that affects the ability to move food through the esophagus, the tube that carries food from the throat to the stomach. It can lead to severe feeding difficulties and low blood sugar (hypoglycemia). Addison disease, also known as primary adrenal insufficiency, is caused by abnormal function of the small hormone-producing glands on top of each kidney (adrenal glands). The main features of Addison disease include fatigue, loss of appetite, weight loss, low blood pressure, and darkening of the skin. The third major feature of triple A syndrome is a reduced or absent ability to secrete tears (alacrima). Most people with triple A syndrome have all three of these features, although some have only two.

Many of the features of triple A syndrome are caused by dysfunction of the autonomic nervous system. This part of the nervous system controls involuntary body processes such as digestion, blood pressure, and body temperature. People with triple A syndrome often experience abnormal sweating, difficulty regulating blood pressure, unequal pupil size (anisocoria), and other signs and symptoms of autonomic nervous system dysfunction (dysautonomia).

People with this condition may have other neurological abnormalities, such as developmental delay, intellectual disability, speech problems (dysarthria), and a small head size (microcephaly). In addition, affected individuals commonly experience muscle weakness, movement problems, and nerve abnormalities in their extremities (peripheral neuropathy). Some develop optic atrophy, which is the degeneration (atrophy) of the nerves that carry information from the eyes to the brain. Many of the neurological symptoms of triple A syndrome worsen over time.

People with triple A syndrome frequently develop a thickening of the outer layer of skin (hyperkeratosis) on the palms of their hands and the soles of their feet. Other skin abnormalities may also be present in people with this condition.

Alacrima is usually the first noticeable sign of triple A syndrome, as it becomes apparent early in life that affected children produce little or no tears while crying. They develop Addison disease and achalasia during childhood or adolescence, and most of the neurologic features of triple A syndrome begin during adulthood. The signs and symptoms of this condition vary among affected individuals, even among members of the same family.

Achalasia microcephaly

Achalasia-microcephaly is an extremely rare genetic syndrome, reported in a few families to date, characterized by the association of microcephaly, intellectual deficit and achalasia (with symptoms of coughing, dysphagia, vomiting, failure to thrive and aspiration appearing in infancy/early-childhood). Antenatal exposure to Mefloquine was reported in one simplex case. An autosomal recessive inheritance has been proposed.

Achard syndrome

Achard syndrome is a syndrome consisting of arachnodactyly, receding lower jaw, and joint laxity limited to the hands and feet. Hypermobility and subluxations of the joints, increased lateral excursion of the patellas and other findings reflect the increased ligament laxity. It is not clear if it is a distinct entity.

Achard-Thiers syndrome

Achard-Thiers syndrome is a hormonal disorder that occurs in diabetic postmenopausal women. It is characterized by diabetes mellitus and hirsuitism. It combines the features of Adrenogenital syndrome and Cushing syndrome. It is also known as diabetic-bearded woman syndrome.

Acheiropodia

Acheiropody is a very rare condition characterized by bilateral, congenital amputations of the hands and feet. Individuals with this condition are born with complete amputation of the distal humeral epiphysis (end of the upper arm bone) and tibial diaphysis (mid-section of the shin bone), and aplasia (lack of development) of the radius, ulna, fibula, and of all the bones of the hands and feet. The condition appears to affect only the extremities, with no other signs and symptoms reported. It is caused by a defect in the LMBR1 gene and is inherited in an autosomal recessive manner. Walking may be possible for individuals with acheiropody with well-fitted prostheses. With the exception of a couple of affected individuals in Puerto Rico, all other reported cases have occurred in Brazil.

Achondrogenesis type 1A

Achondrogenesis is a group of severe disorders that affect cartilage and bone development. These conditions are characterized by a small body, short limbs, and other skeletal abnormalities. As a result of serious health problems, infants with achondrogenesis usually die before birth, are stillborn, or die soon after birth from respiratory failure. However, some infants have lived for a short time with intensive medical support.

Researchers have described at least three forms of achondrogenesis, designated as type 1A, type 1B, and type 2. The types are distinguished by their signs and symptoms, inheritance pattern, and genetic cause. However, types 1A and 1B are often hard to tell apart without genetic testing.

Achondrogenesis type 1A, which is also called the Houston-Harris type, is the least well understood of the three forms. Type 1A involves abnormal cartilage-forming cells (chondrocytes) and affected infants have extremely short limbs, a narrow chest, short ribs that fracture easily, and a lack of normal bone formation (ossification) in the skull, spine, and pelvis.

Achondrogenesis type 1B

Achondrogenesis is a group of severe disorders that affect cartilage and bone development. These conditions are characterized by a small body, short limbs, and other skeletal abnormalities. As a result of serious health problems, infants with achondrogenesis usually die before birth, are stillborn, or die soon after birth from respiratory failure. However, some infants have lived for a short time with intensive medical support.

Researchers have described at least three forms of achondrogenesis, designated as type 1A, type 1B, and type 2. The types are distinguished by their signs and symptoms, inheritance pattern, and genetic cause. However, types 1A and 1B are often hard to tell apart without genetic testing.

Achondrogenesis type 1B, also known as the Parenti-Fraccaro type, is characterized by extremely short limbs, a narrow chest, and a prominent, rounded abdomen. The fingers and toes are short and the feet may turn inward and upward (clubfeet). Affected infants frequently have a soft out-pouching around the belly-button (an umbilical hernia) or near the groin (an inguinal hernia).

Achondrogenesis type 2

Achondrogenesis is a group of severe disorders that affect cartilage and bone development. These conditions are characterized by a small body, short limbs, and other skeletal abnormalities. As a result of serious health problems, infants with achondrogenesis usually die before birth, are stillborn, or die soon after birth from respiratory failure. However, some infants have lived for a short time with intensive medical support.

Researchers have described at least three forms of achondrogenesis, designated as type 1A, type 1B, and type 2. The types are distinguished by their signs and symptoms, inheritance pattern, and genetic cause. However, types 1A and 1B are often hard to tell apart without genetic testing.

Infants with achondrogenesis type 2, which is sometimes called the Langer-Saldino type, have short arms and legs, a narrow chest with short ribs, and underdeveloped lungs. This condition is also associated with a lack of ossification in the spine and pelvis. Distinctive facial features include a prominent forehead, a small chin, and, in some cases, an opening in the roof of the mouth (a cleft palate). The abdomen is enlarged, and affected infants often have a condition called hydrops fetalis, in which excess fluid builds up in the body before birth.

Achondrogenesis- type 3

Severely abnormal bone development which invariably results in death before or soon after birth . Type III may actually be a part of achondrogenesis type II.

Achondroplasia

Achondroplasia is a form of short-limbed dwarfism. The word achondroplasia literally means "without cartilage formation." Cartilage is a tough but flexible tissue that makes up much of the skeleton during early development. However, in achondroplasia the problem is not in forming cartilage but in converting it to bone (a process called ossification), particularly in the long bones of the arms and legs.

Achondroplasia is similar to another skeletal disorder called hypochondroplasia, but the features of achondroplasia tend to be more severe.

All people with achondroplasia have short stature. The average height of an adult male with achondroplasia is 131 centimeters (4 feet, 4 inches), and the average height for adult females is 124 centimeters (4 feet, 1 inch). Characteristic features of achondroplasia include an average-size trunk, short arms and legs with particularly short upper arms and thighs, limited range of motion at the elbows, and an enlarged head (macrocephaly) with a prominent forehead. Fingers are typically short and the ring finger and middle finger may diverge, giving the hand a three-pronged (trident) appearance. People with achondroplasia are generally of normal intelligence.

Health problems commonly associated with achondroplasia include episodes in which breathing slows or stops for short periods (apnea), obesity, and recurrent ear infections. In childhood, individuals with the condition usually develop a pronounced and permanent sway of the lower back (lordosis) and bowed legs. Some affected people also develop abnormal front-to-back curvature of the spine (kyphosis) and back pain. A potentially serious complication of achondroplasia is spinal stenosis, which is a narrowing of the spinal canal that can pinch (compress) the upper part of the spinal cord. Spinal stenosis is associated with pain, tingling, and weakness in the legs that can cause difficulty with walking. Another uncommon but serious complication of achondroplasia is hydrocephalus, which is a buildup of fluid in the brain in affected children that can lead to increased head size and related brain abnormalities.

Achromatopsia

Achromatopsia (ACHM, also known as total color blindness), is a medical syndrome that exhibits symptoms relating to at least five conditions. The term may refer to acquired conditions such as cerebral achromatopsia, also known as color agnosia, but it typically refers to an autosomal recessive congenital color vision condition, the inability to perceive color and to achieve satisfactory visual acuity at high light levels (typically exterior daylight). The syndrome is also present in an incomplete form which is more properly defined as dyschromatopsia. It is estimated to affect 1 in 40,000 live births worldwide.

There is some discussion as to whether achromats can see color or not. As illustrated in The Island of the Colorblind by Oliver Sacks, some achromats cannot see color, only black, white, and shades of grey. With five different genes currently known to cause similar symptoms, it may be that some do see marginal levels of color differentiation due to different gene characteristics. With such small sample sizes and low response rates, it is difficult to accurately diagnose the 'typical achromatic conditions'. If the light level during testing is optimized for them, they may achieve corrected visual acuity of 20/100 to 20/150 at lower light levels, regardless of the absence of color. One common trait is hemeralopia or blindness in full sun. In patients with achromatopsia, the cone system and fibres carrying color information remain intact. This indicates that the mechanism used to construct colors is defective.

Achromatopsia 1

A rare form of colorblindness involving complete rod monochromatism which means that that there is no color can be seen and everything appears gray.

Achromatopsia 2

A rare form of colorblindness involving atypical rod monochromatism which and causing pendular nystagmus and photophobia. Achromatopsia 2 is a condition that affects the color vision. Most people have complete achromatopsia which is characterized by a total absence of color vision (only able to see black, white and shades of gray). Rarely, affected people may have incomplete achromatopsia which is associated with some color discrimination.