Diseases

Ohtahara syndrome

Ohtahara syndrome (OS, also known as Early Infantile Epileptic Encephalopathy with Burst-Suppression ,EIEE), is a progressive epileptic encephalopathy. The syndrome is outwardly characterized by tonic spasms and partial seizures, and receives its more elaborate name from the pattern of burst activity on an electroencephalogram (EEG). It is an extremely debilitating progressive neurological disorder, involving intractable seizures and severe mental retardation. No single cause has been identified, although in many cases structural brain damage is present.

It is named for the Japanese neurologist Shunsuke Ohtahara (1930–2013), who identified it in 1976.

Okamoto Syndrome

Okamoto syndrome is characterised by congenital hydronephrosis, intellectual deficit, growth retardation, cleft palate, generalised hypotonia and a characteristic face. Cardiac anomalies have also been reported. To date, 6 cases have been reported.

Okamuto Satomura syndrome

A very rare syndrome characterized mainly by kidney, heart and facial abnormalities as well as reduced muscle tone and mental retardation.

Oligodactyly tetramelic postaxial

A malformation involving missing bones in the little fingers or little toes or the complete absence of one or more little fingers or little toes

Oligodendroglioma

Oligodendrogliomas are a type of glioma that are believed to originate from the oligodendrocytes of the brain or from a glial precursor cell. They occur primarily in adults (9.4% of all primary brain and central nervous system tumors) but are also found in children (4% of all primary brain tumors). The average age at diagnosis is 35 years

Oligomeganephrony

A very rare syndrome characterized by abnormal development of the kidneys which results in early kidney failure.

Oligophernia

Subnormal intellectual functioning which originates during the developmental period. This has multiple potential etiologies, including genetic defects and perinatal insults. Intelligence quotient (IQ) scores are commonly used to determine whether an individual is mentally retarded. IQ scores between 70 and 79 are in the borderline mentally retarded range. Scores below 67 are in the retarded range. (Joynt, Clinical Neurology, 1992, Ch55, p28)

Oliver McFarlane syndrome

A rare genetic condition characterized by mental retardation, dwarfism, retinal pigmentary degeneration and hairy eyelashes and eyebrows

Oliver syndrome

A very rare inherited disorder characterized by scalp, skull and limb abnormalities. The range and severity of the symptoms can vary greatly from mild to severe.

Olivopontocerebellar atrophies

Olivopontocerebellar atrophy (OPCA) is a term that describes the degeneration of neurons in specific areas of the brain – the cerebellum, pons, and inferior olives. OPCA is present in several neurodegenerative syndromes, including inherited and non-inherited forms of ataxia (such as the hereditary spinocerebellar ataxia known as Machado-Joseph disease) and multiple system atrophy (MSA), with which it is primarily associated.

Olivopontocerebellar atrophy type 3

A disorder where degeneration of certain parts of the brain and spinal cord results in symptoms such as blindness, tremor, speech problems and ataxia.

Ollier disease

A rare genetic disorder characterized by abnormal bone development.

Olmsted syndrome

A rare congenital condition characterized by progressive thickening and hardening of skin on palms and soles, alopecia and nail abnormalities

Omenn syndrome

Omenn syndrome is an autosomal recessive severe combined immunodeficiency associated with mutations in the recombination activating genes (RAG1 and RAG2), affecting circulating levels of both B-cells and T-cells.

Omodysplasia type 1

very rare syndrome characterized mainly by extremely short stature due to short bones in the arms and legs.

Omphalocele exstrophy imperforate anus

A very rare syndrome characterized mainly by the absence of an anal opening, spine defects and omphalocele (abdominal organ protruding from the belly button).

Omphalomesenteric cyst

A very rare umbilical disorder where the omphalomesenteric duct that forms in the early fetal stages fails to disappear during the first couple of months of development and results in the formation of a cyst. The cyst can become infected

Omsk hemorrhagic fever

A hemorrhagic fever caused by a virus. A serious outbreak occurred in Omsk and hence the name. Transmission occurs through tick bites. The infection has two phases: the first acute phase involves symptoms such as fever, rash and muscle pain and the second phase occurs after a week or two and involves the central nervous system (e.g. delirium, convulsions).

Onchocerciasis

Onchocerciasis, is a disease caused by infection with the parasitic worm Onchocerca volvulus. Symptoms include severe itching, bumps under the skin, and blindness. It is the second most common cause of blindness due to infection, after trachoma.

Oncogenic osteomalacia

Oncogenic osteomalacia (also known as tumor-induced osteomalacia or oncogenic hypophosphatemic osteomalacia), is an uncommon disorder resulting in increased renal phosphate excretion, hypophosphatemia and osteomalacia.

Ophthalmoplegic Muscular dystrophy

A rare disorder characterized by progressive weakness and wasting of the muscles around the eyes. Swallowing muscles may eventually become involved as well.

Opisthorchiasis

Infection with a type of fluke (Southeast Asian liver fluke or cat liver fluke). Infection usually occurs by consuming infected undercooked fish. Acute infection may cause fever, joint pain, rash, eosinophilia and lymphadenopathy where as chronic infections may cause enlarged liver, malnutrition. Mild cases can cause constipation, diarrhea and abdominal pain. Occasionally, the infection may be asymptomatic and in the other extreme, severe cases may result in complications such as cholangiocarcinoma.