| neuropathies, hereditary sensory and autonomic | A group of inherited disorders in which there is selective involvement of the peripheral sensory and autonomic neurons and degeneration of fibres by axonal atrophy and degeneration. Five types of disorders have been described and classified type I through type v. (12 Dec 1998) |
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| oedema, hereditary angioneurotic | A genetic form of angioedema. (Angioedema is also referred to as Quinke's disease.) Persons with it are born lacking an inhibitor protein (called C1 esterase inhibitor) that normally prevents activation of a cascade of proteins leading to the swelling of angioedema. Patients can develop recurrent attacks of swollen tissues, pain in the abdomen, and swelling of the voice box (larynx) which can compromise breathing. The diagnosis is suspected with a history of recurrent angioedema. It is confirmed by finding abnormally low levels of C1 esterase inhibitor in the blood. Treatment options include antihistamines and male steroids (androgens) that can also prevent the recurrent attacks. Also called hereditary angioedema. (12 Dec 1998) |
| optic atrophy, hereditary | An inherited disorder in which optic atrophy is associated with muscle weakness, peroneal muscular atrophy and, in some patients, lancinating pains. In these patients the peripheral sensory neurons are probably affected. (12 Dec 1998) |
| telangiectasia, hereditary haemorrhagic | An autosomal dominant vascular anomaly characterised by the presence of multiple small telangiectases of the skin, mucous membranes, gastrointestinal tract, and other organs, associated with recurrent episodes of bleeding from affected sites and gross or occult melena. (12 Dec 1998) |
| elliptocytosis, hereditary | An intrinsic defect of erythrocytes inherited as an autosomal dominant trait. The erythrocytes assume an oval or elliptical shape. (12 Dec 1998) |
| exostoses, multiple hereditary | Hereditary disorder transmitted by an autosomal dominant gene and characterised by multiple exostoses (multiple osteochondromas) near the ends of long bones. The genetic abnormality results in a defect in the osteoclastic activity at the metaphyseal ends of the bone during the remodeling process in childhood or early adolescence. The metaphyses develop benign, bony outgrowths often capped by cartilage. A small number undergo neoplastic transformation. (12 Dec 1998) |
| eye diseases, hereditary | Transmission of gene defects or chromosomal aberrations/abnormalities which are expressed in extreme variation in the structure or function of the eye. These may be evident at birth, but may be manifested later with progression of the disorder. (12 Dec 1998) |
| Leber's hereditary optic atrophy | Hereditary degeneration of the optic nerve and papillomacular bundle with resulting rapid loss of central vision, progressive for several weeks, then usually stationary with permanent central scotoma; age of onset is variable, most often in the third decade; more males than females are affected and transmission is cytoplasmic and strictly on the female side. Mutation on the mitochondrial chromosome involved, which presumably interacts with an X-linked mutant. This mechanism may explain the bizarre sex ratio, which differs significantly from one country to another. (05 Mar 2000) |
| abducens nerve | <anatomy, nerve> The 6th cranial nerve. The abducens nerve originates in the abducens nucleus of the pons and sends motor fibres to the lateral rectus muscles of the eye. Damage to the nerve or its nucleus disrupts horizontal eye movement control. (12 Dec 1998) |
| abducent nerve | <anatomy> The abducent nerve enervates a muscle which moves the eyeball. Lesions of the sixth cranial nerve result in deviation of the eyeball outward and double vision. Synonym: cranial nerve VI. (27 Sep 1997) |
| accessory nerve | <anatomy, nerve> The accessory nerve enervates the sternocleidomastoid muscles and the trapezius muscles. Lesions of the eleventh result in drooping of the shoulder and inability to rotate the head away from the affected side. Synonym: cranial nerve XI. (27 Sep 1997) |
| accessory nerve lymph nodes | The nodes of the lateral deep cervical group that are located along the accessory nerve; their efferent vessels pass to the supraclavicular lymph nodes. Synonym: companion lymph nodes of accessory nerve, nodi lymphatici comitantes nervi accessorii. (05 Mar 2000) |
| accessory nerve trunk | Part of the accessory nerve formed within the cranial cavity by the union of the cranial and spinal roots, which then divides within the jugular foramen into internal and external branches, the former uniting with the vagus, the latter exiting the foramen as in independent branch which is commonly considered to be the accessory nerve. (05 Mar 2000) |
| accessory portion of spinal accessory nerve | <anatomy, nerve> The roots of the accessory nerve which arise from the medulla; the nerve fibres of the cranial root join the intracranial portion of the vagus nerve and are distributed to the pharyngeal plexus, providing the motor innervation of the soft palate (except the tensor veli palati) and the pharynx. Synonym: pars vagalis nervi accessorii, radices craniales, accessory portion of spinal accessory nerve, cranial roots, vagal part of accessory nerve, vagal part. (05 Mar 2000) |
| accommodation of nerve | <anatomy, nerve> The property of a nerve by which it adjusts to a slowly increasing strength of stimulus, so that its threshold of excitation is greater than it would be were the stimulus strength to have risen more rapidly. (05 Mar 2000) |