| mating type gene | Genes that, in Saccharomyces cerevisiae specify into which of the two mating types (a and _) a particular cell falls. Only unlike mating type haploids will fuse. The interest derives from the way in which mating type is switched, the existing gene is removed and a new gene, derived from a (silent) master copy elsewhere in the genome is spliced in. Later this gene will in its turn be replaced by a new copy of the old gene, also derived from a silent master. The a and _ genes code for pheromones that affect cells of the opposite mating type. Similar mating type genes are known from other yeasts and the switching mechanism (cassette mechanism) may be used more generally. (18 Nov 1997) |
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| viral hepatitis type A | A virus disease with a short incubation period (usually 15 to 50 days), caused by hepatitis A virus, a member of the family Picornaviridae, often transmitted by faecal-oral route; may be inapparent, mild, severe, or occasionally fatal and occurs sporadically or in epidemics, commonly in school-age children and young adults; necrosis of periportal liver cells with lymphocytic and plasma cell infiltration is characteristic and jaundice is a common symptom. Synonym: epidemic hepatitis, hepatitis A, infectious hepatitis, MS-1 hepatitis, short incubation hepatitis, virus A hepatitis. (05 Mar 2000) |
| viral hepatitis type B | A virus disease with a long incubation period (usually 50 to 160 days), caused by hepatitis B virus, a DNA virus and member of the family Hepadnoviridae, usually transmitted by injection of infected blood or blood derivatives or by use of contaminated needles, lancets, or other instruments; clinically and pathologically similar to viral hepatitis type A, but there is no cross-protective immunity; HBsAg is found in the serum and the hepatitis delta virus occurs in some patients. Synonym: hepatitis B, serum hepatitis, transfusion hepatitis, virus B hepatitis. (05 Mar 2000) |
| viral hepatitis type C | Principal cause of non-A, non-B posttransfusion hepatitis caused by an RNA virus that may be related to Flaviviridae family. Synonym: hepatitis C, virus C hepatitis. (05 Mar 2000) |
| viral hepatitis type D | Acute or chronic hepatitis caused by the hepatitis delta virus, a defective RNA virus requiring HBV for replication. The acute type occurs in two forms: 1) coinfection, the simultaneous occurrence of hepatitis B virus and hepatitis delta virus infections, which usually is self-limiting; 2) superinfection, the appearance of hepatitis delta virus infection in a hepatitis B virus carrier, which often leads to chronic hepatitis The chronic type appears to be more severe than other types of viral hepatitis. Synonym: delta hepatitis, hepatitis D. (05 Mar 2000) |
| viral hepatitis type E | Hepatitis caused by a nonenveloped, single-stranded, positive-sense RNA virus 27-34 nm in diameter, unrelated to other hepatitis; it is the principal cause of enterically transmitted, waterborne, epidemic NANB hepatitis occurring primarily in Asia and Africa. Synonym: hepatitis E. (05 Mar 2000) |
| central Recklinghausen's disease type II | type 1 neurofibromatosis |
| central type neurofibromatosis | Type I neurofibromatosis. Incomplete neurofibromatosis, multiple neurofibromas with minimal manifestations, perhaps limited to cafe-au-lait spots; individuals with minimal lesions may have offspring with severe involvement. Synonym: abortive neurofibromatosis. (05 Mar 2000) |
| glycogen storage disease type I | <disease> An autosomal recessive disease in which gene expression of glucose-6-phosphatase is absent, resulting in hypoglycaemia due to lack of glucose production. Accumulation of glycogen in liver and kidney leads to organomegaly, particularly massive hepatomegaly. Increased concentrations of lactic acid and hyperlipidemia appear in the plasma. Clinical gout often appears in early childhood. Inheritance: autosomal recessive. (12 Dec 1998) |
| glycogen storage disease type II | <disease> Glycogenosis due to alpha-1,4-glucosidase (acid maltase) deficiency. It affects muscle, heart, and other organs. (12 Dec 1998) |
| glycogen storage disease type III | <disease> An autosomal recessive metabolic disorder due to deficient expression of amylo-1,6-glucosidase (one part of the glycogen debranching enzyme system). The clinical course of the disease is similar to that of glycogen storage disease type I, but milder. Massive hepatomegaly, which is present in young children, diminishes and occasionally disappears with age. Levels of glycogen with short outer branches are elevated in muscle, liver, and erythrocytes. Six subgroups have been identified, with subgroups type IIIa and type IIIb being the most prevalent. Inheritance: autosomal recessive (12 Dec 1998) |
| glycogen storage disease type IV | <disease> An autosomal recessive metabolic disorder due to a deficiency in expression of branching enzyme (alpha-1,4-glucan-6-alpha-glucosyltransferase), resulting in an accumulation of abnormal glycogen with long outer branches. Clinical features are muscle hypotonia and cirrhosis. Death from liver disease usually occurs before age 2. Inheritance: autosomal recessive (12 Dec 1998) |
| glycogen storage disease type V | <disease> Glycogenosis due to muscle phosphorylase deficiency. Characterised by painful cramps following sustained exercise. Inheritance: autosomal recessive (12 Dec 1998) |
| glycogen storage disease type VI | <disease> A hepatic glycogen storage disease in which there is an apparent deficiency of hepatic phosphorylase activity. However, studies have not been able to distinguish between phosphorylase deficiency and phosphorylase kinase deficiency in patients with hepatic glycogenosis. (12 Dec 1998) |
| glycogen storage disease type VII | <disease> An autosomal recessive muscle glycogen storage disease in which there is deficient expression of muscle phosphofructokinase activity, resulting in increased concentrations of glucose-6-phosphate and fructose-6-phosphate and low concentrations of fructose-1,6-diphosphate in muscle tissue. Glycogen storage in muscle is increased, perhaps due to activation of glycogen synthase by accumulated glucose-6-phosphate. It has been proposed that shunting of glucose-6-phosphate and fructose-6-phosphate into the pentose phosphate pathway may result in increased synthesis of purines and pyrimidines, causing hyperuricaemia and gout. Erythrocytes from patients may show decreased phosphofructokinase activity and 2,3-diphosphoglycerate deficiency. Exercise intolerance is present and severe congenital muscular dystrophy has been reported. Inheritance: autosomal recessive (12 Dec 1998) |