| OASP | organic acid soluble phosphorus |
|---|---|
| OBD | organic brain disease |
| OHD | hydroxyvitamin D; Office of Human Development; Ondine-Hirschsprung disease; organic heart disease |
| OIT | organic integrity test |
| OMD | ocular muscle dystrophy; oculomandibulodyscephaly; organic mental disorder; oromandibular dystonia |
| amniotic fluid syndrome | <syndrome> Pulmonary embolic phenomena thought to be due to infusion of amniotic fluid containing epithelial squames into maternal blood vessels; shock ensues and sudden death may occur. (05 Mar 2000) |
|---|---|
| Amsterdam syndrome | <syndrome> A congenital anomaly characterised by impaired development, mental retardation, characteristic facies with snyophrys and hairline well down on forehead, depressed bridge of nose with uptilted tip of nose, small head with low-set ears, and flat spadelike hands with simian crease and short tapering fingers. Synonym: Amsterdam syndrome, Cornelia de Lange syndrome. (05 Mar 2000) |
| androgenital syndrome | <syndrome> A genetic disorder present at birth characterised by a deficiency of the hormones aldosterone and cortisol and an overproduction of male sex hormones (androgens). In males this may manifest as enlarged penis, small testes and early development of masculine characteristics. In females features include ambiguous genitalia, failure to menstruate, deep voice and excessive hair. (27 Sep 1997) |
| angelman syndrome | <syndrome> A dysmorphic mental retardation syndrome, that has generated considerable interest in human genetics as a prototypic example of genomic imprinting in man. Usually a sporadic disorder, it is characterised by profound intellectual deficiency, a striking puppet-like ataxic gait and facial features, paroxysmal laughter and seizures. These features are responsible for its alternative designation as happy puppet syndrome. An interstitial deletion at chromosome band 15q12 was identified and can be detected in a large proportion of cases and the defect is linked to the GABA receptor gene. Chromosome haplotyping will always reveal the deletion to be carried on the maternally-derived chromosome 15, alternatively, Angelman syndrome can be caused by uniparental disomy for the paternal chromosome 15. In both cases, this suggests that Angelman syndrome results from loss or disruption of a gene (or genes) on chromosome 15 that must be inherited through the maternal gamete in order to be properly expressed. The opposite phenomenon is seen in the Prader-Willi syndrome, in which a deletion of a nearby region on chromosome 15q is found on the paternally-derived chromosome, or there can be uniparental disomy for the maternally derived chromosome. Thus, both disorders seem to represent examples of genes which are subject to imprinting. (16 Dec 1997) |
| Angelucci's syndrome | <syndrome> Extreme excitability, vasomotor disturbances, and palpitation associated with vernal conjunctivitis. (05 Mar 2000) |
| angio-osteohypertrophy syndrome | <syndrome> A congenital malformation syndrome characterised by the triad of asymmetric limb hypertrophy, haemangiomata, and nevi. Asymmetric limb hypertrophy is enlargement of one limb and not the corresponding limb on the other side, the enlarged limb being 3 times more likely to be a leg than an arm in ktw; and the limb enlargement is of bone as well as soft tissue. The haemangiomas, abnormal nests of blood vessels that proliferate inappropriately and excessively, cover a remarkable range from small innocuous capillary haemangiomas ( strawberry marks ) to huge cavernous haemangiomas. The nevi are pigmented moles on the skin; in ktw there are often also dark linear streaks on the skin, streaks due to too much pigment. There can be other abnormalities but the triad is the consistent clinical centrepiece of the disease. most persons with ktw have an enlarged leg and do relatively well without treatment or, for example, with only compression from an elastic stocking. Skin ulcers and other skin problems can occur over the swollen leg. Usually, the treatment is conservative. Surgery is almost never needed. The only possible exceptions are the very rare situations in which the leg reaches gigantic proportions or secondary clotting difficulties arise (due to trapping and destruction of blood platelets in a huge haemangioma). Then, amputation may become necessary. The cause of ktw syndrome is unknown. (12 Dec 1998) |
| ankyloglossia superior syndrome | <syndrome> A congenital condition in which the tongue adheres to the hard palate; no evidence of genetic factors. (05 Mar 2000) |
| anorectal syndrome | <syndrome> Soreness, burning, itching, or other irritation of the rectum together with redness about the anus, and sometimes accompanied by diarrhoea, occurring as a toxic effect of the oral administration of certain broad spectrum antibiotics. (05 Mar 2000) |
| anterior chamber cleavage syndrome | <syndrome> A congenital disorder originating from faulty separation of embryonic structures; it results in bilateral central corneal opacities, with an anterior ring attachment of the iridic pupillary border and anterior polar cataracts; associated with short-limbed dwarfism; autosomal dominant inheritance. See: iridocorneal endothelial syndrome. Synonym: Peters' anomaly. (05 Mar 2000) |
| anterior compartment syndrome | <syndrome> Rapid swelling, increased tension, pain, and ischemic necrosis of the muscles of the anterior tibial compartment of the leg, often following excessive exertion. (12 Dec 1998) |
| anterior tibial compartment syndrome | <syndrome> Ischemic necrosis of the muscles of the anterior tibial compartment of the leg, presumed due to compression of arteries by swollen muscles following unaccustomed exertion. (05 Mar 2000) |
| antibody deficiency syndrome | <syndrome> Any of a group of disorders associated with a defective antibody production due to defects in the B-type lymphocyte system or in T-type lymphocytes; chief manifestation is an increased susceptibility to infection by various microorganisms. See: agammaglobulinaemia, hypogammaglobulinaemia, immunodeficiency. Synonym: antibody deficiency disease. (05 Mar 2000) |
| antiphospholipid antibody syndrome | <syndrome> An immune disorder characterised by the presence of abnormal antibodies in the blood associated with certain medical conditions including abnormal blood clotting, migraine headaches, premature miscarriage, and low blood platelet counts (thrombocytopenia). (12 Dec 1998) |
| antiphospholipid syndrome | <immunology, syndrome> An uncommon disorder that is characterised by hypercoagulability due to the presence of antibodies against phospholipids. These patients exhibit a tendency for recurrent and life-threatening thrombosis and embolic events (for example stroke). Individuals with antiphospholipid syndrome also have an increased tendency toward deep venous thrombosis, myocardial infarction and spontaneous abortions in females. Antiphospholipid syndrome may be seen by itself or in association with other autoimmune illnesses (for example lupus) or with some infections. Treatment includes long-term heparin and warfarin. (13 Jan 1998) |
| Anton's syndrome | <syndrome> In cortical blindness, lack of awareness of being blind. (05 Mar 2000) |