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All Communities

  • Ochoa Syndrome

    4 members

    Ochoa Syndrome is a rare inherited disorder characterized by inverted facial expressions.

  • Ocular Convergence Spasm

    1 members

    Ocular Convergence Spasm is a rare disorder where the eyes turn towards each other.

  • Ocular Melanoma

    3 members

    Ocular Melanoma is a rare type of melanoma of the eye.

  • Oculocutaneous Albinism

    7 members

    Oculocutaneous Albinism is a rare disorder characterized by a partial or total lack of melanin pigment in the eyes, skin and hair.

  • Oculodentodigital Syndrome

    3 members

    Oculodentodigital Syndrome is a rare genetic disorder resulting in small eyes, underdeveloped teeth, and malformation of the fourth and fifth fingers.



  • Oculofaciocardiodental Syndrome

    7 members

    Oculofaciocardiodental Syndrome is a rare disorder causeed by the deletion of the BCOR gene affecting the eyes, face, teeth, and heart.

  • Oculopharyngeal Muscular Dystrophy

    1 members

  • Ohdo Syndrome

    5 members

    Ohdo Syndrome is a rare disorder characterized by learning disabilities associated with congenital heart disease, blepharophimosis (small eye openings), blepharoptosis (drooping eyelids), and small...

  • Olivopontocerebellar Atrophy

    7 members

    Olivopontocerebellar Atrophy (OPCA) is a term used to define neuronal degeneration in the cerebellum, pontine nuclei, and inferior olivary nucleus.

  • Ollier's Disease

    3 members

    Ollier's Disease is a disorder when multiple sites in the body develop cartilage cyst found in the bone marrow.

  • Omphalocele

    2 members

  • Ondine syndrome


    Ondine syndrome is a rare respiratory disorder that is fatal if untreated.

  • Opitz BBB/G Syndrome

    5 members

    Opitz G/BBB Syndrome is a genetic disorder caracterized by wide-spaced eyes; and breathing problems and difficulty swallowing.

  • Oral Lichen Planus

    8 members

    Oral Lichen Planus is an inflammatory condition affecting the lining of the mouth. It occurs most often on the inside of the cheeks, but can affect the gums, tongue, lips and other parts of the mou...

  • Ornithine Transcarbamylase Deficiency

    7 members

    Ornithine Transcarbamylase Deficiency is a rare metabolic disorder the affects the enzyme ornithine transcarbamylase and the body's ability to get rid of ammonia.



  • Orofaciodigital Syndrome

    1 members

  • Orotic Aciduria Hereditary

    3 members

    Orotic Aciduria Hereditary is a rare metabolic disorder characterized by the body's inability to break down orotic acid.

  • Osteochondritis Dissecans

    5 members

    Osteochondritis Dissecans is a rare joint disorder in which cracks form in the articular cartilage and underlying subchondral bone.

  • Osteogenesis Imperfecta

    7 members

    Osteogenesis imperfecta (OI) is a group of rare genetic disorders that affect the bones and its connective tissues. Affected individuals have extremely brittle bones...

  • Osteoporosis pseudoglioma syndrome

    2 members

    Osteoporosis pseudoglioma syndrome is a rare genetic disorder characterized by severe juvenile onset of osteoporosis and vision loss resulting from retinal detachment due to an inflammatory eye con...

  • Osteosarcoma

    1 members

  • Ouvrier-Billson Syndrome

    6 members

    Ouvrier-Billson Syndrome usually shows up in an infant before the age of 12 months and is characterized by eyes drifting up in an upward gaze and fluttering. The child compensates by lowering their...