Leber congenital amaurosis 9 (LCA9) is a rare inherited retinal disease (retinal dystrophy) that starts during the fetal stage. Vision impairment is obvious at birth or within months of birth. Type 9 is distinguished from the other forms of this condition by the genetic origin of the defect - chromosome 1p36.
Leber's hereditary optic neuropathy (LHON) is a mitochondrially inherited (transmitted from mother to offspring) degeneration of retinal ganglion cells (RGCs) and their axons that leads to an acute or subacute loss of central vision; this affects predominantly young adult males. However, LHON is only transmitted through the mother as it is primarily due to mutations in the mitochondrial (not nuclear) genome and only the egg contributes mitochondria to the embryo. LHON is usually due to one of three pathogenic mitochondrial DNA (mtDNA) point mutations. These mutations are at nucleotide positions 11778 G to A, 3460 G to A and 14484 T to C, respectively in the ND4, ND1 and ND6 subunit genes of complex I of the oxidative phosphorylation chain in mitochondria. Men cannot pass on the disease to their offspring.
A rare condition characterized by a localized group of dilated blood capillaries and aneurysms in the retina of one eye. It is believed to be a mild form of Coat's disease.
A rare disorder where numerous fibrous nodules develop in the bottom of the foot and eventually affect the tendons in the foot which can cause foot problems.
An abnormal opening that connects the left ventricle and the ascending aorta.
Left ventricular non-compaction (LVNC) is a rare genetic disease of the heart muscle, also called Non-compaction cardiomyopathy (NCC), spongiform cardiomyopathy. Compaction is a process that occurs during the development of the heart when a baby is in the womb. If this process is not complete, the inside of the heart muscle (the one in contact with the blood) will look spongy or “trabeculated”. Normally, it is smooth. Originally, non-compaction was diagnosed very rarely. It seemed to be associated with dangerous heart rhythms and, often, severe weakness of the heart muscle. Sometimes, if the trabeculations are deep, a blood thinning medication is used. In some cases, implantation of a defibrillator may be required to treat dangerous rhythms. In very severe cases, heart transplantation is sometimes required but this is rare.
A very rare disorder where the gallbladder is located in the left side of the abdomen. Generally this causes no symptoms but may be important if abdominal surgery is being undertaken.
A very rare syndrome characterized mainly by missing bones in one leg, cataracts and progressive spinal curvature.
Legg–Calvé–Perthes syndrome is a degenerative disease of the hip joint, where a add/loss of bone mass leads to some degree of collapse of the hip joint, that is, to deformity of the ball of the femur and the surface of the hip socket. The disease is typically found in young children and small dogs, and it can lead to osteoarthritis in adults. The effects of Perthes can also sometimes continue into adulthood.
Legionnaires' disease (LEE-juh-nares) is caused by a type of bacteria called Legionella. The bacteria got its name in 1976, when many people who went to a Philadelphia convention of the American Legion suffered from an outbreak of this disease, a type of pneumonia (lung infection). Although this type of bacteria was around before1976, more illness from Legionnaires' disease is being detected now. This is because we are now looking for this disease whenever a patient has pneumonia.
Legionnaires' disease (also known as legionellosis or Legion fever), is a form of atypical pneumonia caused by any type of Legionella bacteria. Over 90% of cases of Legionnaires' disease are caused by Legionella pneumophila.
Other causative species include L. longbeachae, L. feeleii, L. micdadei, and L. anisa. These species cause a less severe infection known as Pontiac fever, which resembles acute influenza. These bacterial species can be water-borne or present in soil, whereas L. pneumophila has only been found in aquatic systems, where it is symbiotically present in aquatic-borne amoebae. It thrives in temperatures between 25 and 45 °C (77 and 113 °F), with an optimum temperature of 35 °C (95 °F). During infection, the bacterium invades macrophages and lung epithelial cells and reproduces within the infected cells.
A condition characterised by the duplication of the long arm of chromosome X
A rare birth disorder characterized by eye cavity cysts, brain anomalies, facial skin tags and various other skin lesions.
A very rare syndrome characterized mainly by.
Leigh syndrome is a severe neurological disorder that usually becomes apparent in the first year of life. This condition is characterized by progressive loss of mental and movement abilities (psychomotor regression) and typically results in death within two to three years, usually due to respiratory failure. A small number of individuals do not develop symptoms until adulthood or have symptoms that worsen more slowly.
The first signs of Leigh syndrome seen in infancy are usually vomiting, diarrhea, and difficulty swallowing (dysphagia), which disrupts eating. These problems often result in an inability to grow and gain weight at the expected rate (failure to thrive). Severe muscle and movement problems are common in Leigh syndrome. Affected individuals may develop weak muscle tone (hypotonia), involuntary muscle contractions (dystonia), and problems with movement and balance (ataxia). Loss of sensation and weakness in the limbs (peripheral neuropathy), common in people withLeigh syndrome, may also make movement difficult.
Several other features may occur in people with Leigh syndrome. Many individuals with this condition develop weakness or paralysis of the muscles that move the eyes (ophthalmoparesis); rapid, involuntary eye movements (nystagmus); or degeneration of the nerves that carry information from the eyes to the brain (optic atrophy). Severe breathing problems are common, and these problems can worsen until they cause acute respiratory failure. Some affected individuals develop hypertrophic cardiomyopathy, which is a thickening of the heart muscle that forces the heart to work harder to pump blood. In addition, a substance called lactate can build up in the body, and excessive amounts are often found in the blood, urine, or the fluid that surrounds and protects the brain and spinal cord (cerebrospinal fluid) of people with Leigh syndrome.
The signs and symptoms of Leigh syndrome are caused in part by patches of damaged tissue (lesions) that develop in the brains of people with this condition. A medical procedure called magnetic resonance imaging (MRI) reveals characteristic lesions in certain regions of the brain. These regions include the basal ganglia, which help control movement; the cerebellum, which controls the ability to balance and coordinates movement; and the brainstem, which connects the brain to the spinal cord and controls functions such as swallowing and breathing. The brain lesions are often accompanied by loss of the myelin coating around nerves (demyelination), which reduces the ability of the nerves to activate muscles used for movement or relay sensory information from the rest of the body back to the brain.
There is also a form of Leigh disease (called X-linked Leigh disease) which is the result of mutations in a gene that produces another group of substances that are important for cell metabolism. This gene is only found on the X chromosome.
A rare, progressive, inherited metabolic disorder where a deficiency of the enzyme cytochrome C oxidase affects skeletal muscles, connective tissue, brain and liver.
Leiner disease occurs in infants and is characterised by severe generalised seborrhoeic dermatitis, recurrent diarrhoea, recurrent skin and internal infections, and failure to thrive. It is also known as ‘erythroderma desquamativum’. Leiner disease may be present at birth but more commonly develops within the first few months of life. It appears to be more common in females than males and in breast-fed infants.
Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a hereditary condition associated with multiple leiomyomas (fibroid skin tumors), uterine fibroids (non-cancerous growths), and type 2 papillary renal (kidney) cancer. A person with HLRCC can have a few skin tumors or many skin tumors. These tumors generally develop in adulthood and occur on the chest, back, arms, and legs; the tumors can be painful, but they are not cancerous. Women with HLRCC can develop uterine fibroids as young as their teens or early 20s.
A rare syndrome characterized by the development of a number of benign skin tumors that develops from smooth muscle tissue. In familial cases, the condition occurs in several members of a family. Tumors may also occur in other parts of the body.
A very rare syndrome characterized mainly by cataracts, benign esophageal tumors and kidney cell cancer.
A leiomyosarcoma belongs to a group of cancers called soft tissue sarcomas. Sarcomas are cancers that develop in the supporting or connective tissues of the body (such as muscle, fat, nerves, blood vessels, bone, and cartilage). They are rare. Approximately 1,200–2,000 people will be diagnosed with a sarcoma each year in the UK. Most people with leiomyosarcoma will be over the age of 50.
A very rare syndrome characterized mainly by short stature and abnormal segmentation of the vertebrae in the abdominal segment of the spine
Leishmaniasis is a parasitic disease spread by the bite of infected sand flies. There are several different forms of leishmaniasis. The most common are cutaneous and visceral. The cutaneous type causes skin sores. The visceral type affects internal organs such as the spleen, liver and bone marrow. People with this form usually have fever, weight loss, and an enlarged spleen and liver. Visceral disease can be deadly without proper treatment. Leishmaniasis is found in parts of the Middle East, Central America, South American, Asia, Africa, and southern Europe. Most of these countries are in the tropics and subtropics.
Leishmaniasis is considered one of the classic causes of a markedly enlarged (and therefore palpable) spleen; the organ, which is not normally felt during examination of the abdomen, may even become larger than the liver in severe cases.
A triad of short stature, speech and psychomotor development delay, and facial anomalies. The original cases were reported at the Boston Floating Hospital and Harbor General Hospital, Torrance, California, hence the name Floating-Harbor syndrome. Source - Diseases Database
Lemierre's syndrome (or Lemierre's disease, also known as postanginal sepsis and human necrobacillosis) is a disease usually caused by the bacterium Fusobacterium necrophorum, and occasionally by other members of the genus Fusobacterium (F. nucleatum, F. mortiferum and F. varium etc.) and usually affects young, healthy adults. Lemierre syndrome develops most often after a strep sore throat has created a peritonsillar abscess, a crater filled with pus and bacteria near the tonsils. Deep in the abscess, anaerobic bacteria (microbes that do not require oxygen) like Fusobacterium necrophorum can flourish. The bacteria penetrate from the abscess into the neighboring jugular vein in the neck and there they cause an infected clot (thrombosis) to form, from which bacteria are seeded throughout the body by the bloodstream (bacteremia). Pieces of the infected clot break off and travel to the lungs as emboli blocking branches of the pulmonary artery bringing the heart's blood to the lungs. This causes shortness of breath, chest pain and severe pneumonia. Fusobacteria are normal inhabitants of the oropharyngeal flora. This is a very rare disease with only approximately 160 cases in the last 100 years.[1]
A rare degenerative disorder of the heart conduction system.
Lennox–Gastaut syndrome (LGS) is a difficult-to-treat form of childhood-onset epilepsy that most often appears between the second and sixth year of life. LGS is characterized by a triad of signs including frequent seizures of multiple types, an abnormal EEG pattern of less than 2.5 Hz slow spike wave activity, and moderate to severe intellectual impairment.
Lentigo maligna melanoma is a melanoma that has evolved from a lentigo maligna. They are usually found on chronically sun damaged skin such as the face and the forearms of the elderly. The nomeclature is very confusing to both patients, dermatologists, and pathologists alike. Lentigo maligna is the non-invasive skin growth that some pathologists consider to be a melanoma-in-situ. A few pathologists do not consider lentigo maligna to be a melanoma at all, but a precursor to melanomas. Once a lentigo maligna becomes a lentigo maligna melanoma, it is treated as if it were an invasive melanoma.