Diseases

Oculocerebrocutaneous syndrome

A rare birth disorder characterized by eye cavity cysts, brain anomalies, facial skin tags and various other skin lesions.

Oculocerebrorenal syndrome

Oculocerebrorenal syndrome (also called Lowe syndrome) is a X-linked recessive disorder characterized by hydrophthalmia, cataracts, intellectual disabilities, aminoaciduria, reduced renal ammonia production and vitamin D-resistant rickets.

Oculocutaneous albinism type 1

A rare inherited disorder characterized by complete lack of pigmentation in the skin, eyes and hair. Type 1A involves a complete absence of tyrosinase which is needed for the production of melanin which gives the skin, hair and eyes their color - type B involves only a partial absence of tyrosinase. It is caused by mutations in the TYR gene

Oculocutaneous albinism type 1B

A rare inherited disorder characterized by reduced pigmentation of the skin, eyes and hair. Type 1B involves a partial absence of tyrosinase which is needed for the production of melanin which gives the skin, hair and eyes their color. It is caused by mutations in the TYR gene.

Oculocutaneous albinism type 2

A rare inherited disorder characterized by reduced pigmentation in the skin, eyes and hair. Type 2 has normal levels of active tyrosinase which is needed for the production of melanin which gives the skin, hair and eyes their color - the fairness is caused by a different genetic mutation (OCA2 gene).

Oculocutaneous albinism type 3

A rare inherited disorder characterized by slightly reduced pigmentation in the skin, eyes and hair (due to a genetic mutation of the TYRP1 gene). Type 3 is characterized by some pigmentation of the iris despite the complete absence of tyrosinase which is needed for the production of melanin which gives the skin, hair and eyes their color. Type 3 also has the milder eye problems than the other types.

Oculocutaneous tyrosinemia

A rare condition where a deficiency of a liver enzyme (tyrosinase aminotransferase) causes tyrosine levels in the blood to increase and result in eye problems, mental retardation and horny skin lesions

Oculodentodigital syndrome

Oculodentodigital syndrome (ODD syndrome) is an extremely rare genetic condition that typically results in small eyes, underdeveloped teeth, and syndactyly and malformation of the fourth and fifth fingers. It has also been called oculo-dento-digital syndrome, oculodentodigital dysplasia (ODDD), and oculodentoosseous dysplasia (ODOD). It is considered a kind of ectodermal dysplasia.

Oculodentoosseous dysplasia recessive

A very rare recessively inherited syndrome characterized mainly by eye, tooth and finger abnormalities. The eye abnormalities tend to be more severe than in the dominant form of the disorder

Oculomelic amyoplasia

A rare genetic disorder characterized by limb contractures (tightening of muscles which limits movement) from birth and eye abnormalities.

Oculopharyngeal muscular dystrophy

Oculopharyngeal muscular dystrophy (OPMD) is a rare form of muscular dystrophy with symptoms generally starting when an individual is 40 to 50 years old. It can be autosomal dominant neuromuscular disease or autosomal recessive. The most common inheritance of OPMD is autosomal dominant, which means only one copy of the mutated gene needs to be present in each cell. Children of an affected parent have a 50% chance of inheriting the mutant gene.

Autosomal dominant inheritance is the most common form of inheritance. Less commonly, OPMD can be inherited in an autosomal recessive pattern, which means that two copies of the mutated gene need to be present in each cell, both parents need to be carriers of the mutated gene, and usually show no signs or symptoms. The PABPN1 mutation contains a GCG trinucleotide repeat [2]at the 5' end of the coding region, and expansion of this repeat which then leads to autosomal dominant oculopharyngeal muscular dystrophy (OPMD) disease.

Odontoma

A benign tumor that usually forms at the root of a tooth. It may have genetic origins or may result from some sort of trauma to the tooth.

Odontoma dysphagia syndrome

A rare disorder characterized mainly by overgrowth of muscle tissue in the esophagus and a benign tumor that usually forms at the root of a tooth

OFD syndrome type 8

A rare genetic disorder characterized by oral frenula, oral clefts, underdeveloped nose flapss and finger abnormalities.

OFD syndrome type Figuera

A rare genetic disorder characterized by oral frenula, oral clefts, underdeveloped nose flapss, finger abnormalities and absence of all or part of the fibula

Ogilvie’s syndrome

A rare gastrointestinal disorder where the peristaltic action of the colon is absent which prevents fecal matter from passing through.

Oguchi disease

Oguchi disease is an autosomal recessive form of congenital stationary night blindness associated with fundus discoloration and abnormally slow dark adaptation.

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.