| cone dystrophy | A retinal abnormality in which colour perception is severely deficient and typical changes occur in electroretinogram. See: achromatopsia. Synonym: cone degeneration. (05 Mar 2000) |
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| muscular dystrophy | A group of diseases characterised by progressive degeneration and/or loss of muscle fibres without nervous system involvement. All or nearly all of them have a hereditary origin but details of the type of genetic defect and of the prognosis for the disease vary from type to type. Duchenne muscular dystrophy (pseudohypertrophic muscular dystrophy) is the most common form. It is due to a sex-linked recessive allele and this is expressed as an absence of the protein dystrophin, the disease in boys shows extensive but insufficient muscle fibre reformation from satellite cells. (18 Nov 1997) |
| myotonic dystrophy | <neurology> An inherited human neuromuscular disease classed as an autosomal dominant disease in which there is progressive muscle weakening and wasting. A triplet repeat syndromes (like fragile X syndrome), this most common adult form of muscular dystrophy is caused by expansion of the unstable trinucleotide repeat CTG in the 3' untranslated region on chromosome 19q13 (cAMP-dependent muscle protein kinase gene). Anticipation has been associated with further expansion of the repeat upon transmission to subsequent generations (the inheritance pattern is autosomal dominant), although contraction has been noted to occur as well. Especially severe neonatal cases have been born to affected mothers preferentially, suggesting a role for genomic imprinting as well. The classic physical signs include atrophy of facial muscles, cataracts, and delayed muscle relaxation. Detection of the expanded trinucleotide repeat is accomplished by PCR or Southern blot and expansion appears to correlate with decreased transcription of the protein kinase gene. Inheritance: autosomal dominant. (29 Dec 1997) |
| craniocarpotarsal dystrophy | Congenital association of skeletal defects (ulnar deviation of hands with camptodactyly, talipes equinovarus, and frontal bone defects) and characteristic facies (protrusion of lips as in whistling, sunken eyes with hypertelorism, and small nose); autosomal dominant inheritance. Synonym: craniocarpotarsal dysplasia, Freeman-Sheldon syndrome, whistling face syndrome. (05 Mar 2000) |
| progressive muscular dystrophy | A form of progressive muscular atrophy in which the disease begins in the muscle and not in the spinal centres. Synonym: Erb atrophy, idiopathic muscular atrophy. (05 Mar 2000) |
| progressive tapetochoroidal dystrophy | An x chromosome-linked abnormality characterised by atrophy of the choroid and degeneration of the retinal pigment epithelium causing night blindness. (12 Dec 1998) |
| scapulohumeral muscular dystrophy | One of the less well-defined types of muscular dystrophy, probably heterogenous in nature. Onset usually in childhood or early adulthood and both sexes affected. Characterised by weakness and wasting, usually symmetrical, of the pelvic girdle muscles, the shoulder girdle muscles, or both, but not the facial muscles. Muscle pseudohypertrophy, heart involvement, and mental retardation are absent. Variable inheritance. Synonym: Leyden-Mobius muscular dystrophy, pelvofemoral muscular dystrophy, scapulohumeral muscular dystrophy. (05 Mar 2000) |
| pseudohypertrophic muscular dystrophy | The most common childhood muscular dystrophy, with onset usually before age 6. Characterised by symmetrical weakness and wasting of first the pelvic and crural muscles and then the pectoral and proximal upper extremity muscles; pseudohypertrophy of some muscles, especially the calf; heart involvement; sometimes mild mental retardation; progressive course and early death, usually in adolescence. X-linked inheritance (affects males and transmitted by females). Synonym: childhood muscular dystrophy, Duchenne's disease, pseudohypertrophic muscular dystrophy. (05 Mar 2000) |
| hypertrophic dystrophy | Increase in the number of cells in a squamous epithelium. Synonym: hypertrophic dystrophy. (05 Mar 2000) |
| neuroaxonal dystrophy | A rare disorder that begins in the second year of life and is relentlessly progressive; clinically characterised initially by walking difficulties, weakness, and areflexia, later followed by corticospinal and pseudobulbar findings, blindness, loss of pain appreciation, and mental deterioration; pathologically, eosinophilic spheroids of swollen axoplasm are found in various central nuclei; autosomal recessive inheritance. (05 Mar 2000) |
| sympathetic reflex dystrophy | A syndrome of pain and tenderness, usually to a hand or foot, associated with vasomotor instability, skin changes and rapid development of bony demineralisation (osteoporosis). Frequently will follow a localised trauma, stroke or peripheral nerve injury. (27 Sep 1997) |
| syndrome, reflex sympathetic dystrophy | A condition that features a group of typical symptoms, including pain (often burning type), tenderness, and swelling of an extremity associated with varying degrees of sweating, warmth and/or coolness, flushing, discoloration, and shiny skin. (12 Dec 1998) |
| Duchenne dystrophy | The most common childhood muscular dystrophy, with onset usually before age 6. Characterised by symmetrical weakness and wasting of first the pelvic and crural muscles and then the pectoral and proximal upper extremity muscles; pseudohypertrophy of some muscles, especially the calf; heart involvement; sometimes mild mental retardation; progressive course and early death, usually in adolescence. X-linked inheritance (affects males and transmitted by females). Synonym: childhood muscular dystrophy, Duchenne's disease, pseudohypertrophic muscular dystrophy. (05 Mar 2000) |
| Duchenne muscular dystrophy | A specific form of muscular dystrophy that is inherited as a sex-linked recessive trait and thus confined to young males and to females with Turner's syndrome. One third of all cases are estimated to be new mutational events. See: dystrophin. It is characterised by degeneration and necrosis of skeletal muscle fibres, that are replaced by fat and fibrous tissue. Symptoms include muscle weakness and in some forms, the appearance of muscle enlargement (pseudo-hypertrophy). Advanced cases can include weakness of the respiratory muscles (compromising breathing) and cardiomyopathy. Inheritance: sex-linked recessive. Incidence: 1 in 4000 male births. (11 Nov 1997) |
| dystrophy | <pathology> Any disorder arising from defective or faulty nutrition, especially the muscular dystrophies. Origin: L. Dystrophia, Gr. Trephein = to nourish (18 Nov 1997) |