Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In addition to the already recognized metabolic diseases which have been associated with cataract formation, e.g. galactosaemia, galactokinase deficiency, Lowe's syndrome and diabetes, several other disorders can also lead to the development of cataracts. They are sorbitol dehydrogenase deficiency, uridine diphosphate galactose-4-epimerase deficiency, marginal maternal transferase and galactokinase deficiency, galactitol and sorbitol accumulation of unknown origin, heterozygosity for galactosaemia and galactokinase deficiency as well as the carrier state for Lowe's syndrome. In this review these metabolic disorders have been divided into five groups according to the age at the first appearance of lens clouding and the possible means of treatment have been discussed.
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PMID:Cataract and metabolic disease. 212 17

Galactitol and sorbitol concentrations in plasma were determined in patients (with or without cataract) in whom homo- or heterozygosity for galactokinase, galactose-1-phosphate uridyltransferase, systemic or peripheral UDP-galactose epimerase and sorbitol dehydrogenase deficiency was confirmed. For the above disorders it can be concluded that elevation of plasma polyols is not always related to the presence or absence of cataract. In all cases with cataract, however, the plasma galactitol or sorbitol levels were elevated. In another group of patients with unexplained congenital or infantile cataracts, but without apparent enzyme defects, mild to moderately elevated concentrations of plasma galactitol or sorbitol were found in about 45%. In 8% of this group the cataract and the elevated plasma galactitol concentration could possibly have been related to partial maternal enzyme deficiency. In all the other cases the elevated plasma polyol concentration remains unexplained but could indicate a further cause of cataract formation due to a hitherto unknown galactose or glucose metabolic aberration.
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PMID:Plasma polyol levels in patients with cataract. 212 18

Whole blood galactokinase (GK) activities were determined in 278 individuals including 77 patients with senile cataracts, 60 with presenile cataracts and 141 normal controls. No significant difference was found among the GK levels of the three groups. The frequency of GK heterozygocity in the presenile cataract group, however, was significantly higher than that in the normal control group (P less than 0.01), suggesting that even a partial decrease in GK activity might facilitate cataract formation in relatively early stages of life. The intake of milk and its products should be limited, both in GK homo- and heterozygotes.
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PMID:[Studies on blood galactokinase of patients with presenile and senile cataracts]. 214 8

Five hundred patients undergoing cataract surgery were prospectively examined, and 46 Caucasian patients were found to have strictly idiopathic cataracts severe enough to warrant surgery on or before age 55. In a masked fashion we determined the activity of galactokinase (GK) and galactose-1-phosphate uridyl transferase (GPUT) in these patients as well as on 53 age matched controls. With respect to GK no cataract patient had an enzyme level of less than 2 standard deviations below the control mean. However, 3 of 45 (6.7%) patients in the cataract group had a GPUT level less than 2 standard deviations below the mean for controls, and were presumably heterozygotes for this enzyme. In comparison with the expected population rate of 0.8% this is highly significant (p = 0.006). Abnormalities in galactose pathway enzymes may therefore predispose to development of presenile cataracts. In affected people there is a possibility of treating these patients clinically by dietary restriction of dairy products or by using aldose reductase inhibitors to prevent or reverse cataract formation.
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PMID:Idiopathic presenile cataract formation and galactosaemia. 253 52

In order to obtain an experimental model for studying inherited disorders of galactose metabolism in man, we administered to adult rats a diet supplemented with 50% of galactose during 38 days. The results showed clinical symptoms such as polyuria, polydipsia, growth retardation and bilateral cataract. The main biochemical features were an increase in the galactokinase and uridyltransferase activities in liver, an ubiquitous accumulation in tissues and a considerable urinary elimination of galactose and galactitol, a weak accumulation of galactose-1-phosphate in tissue and a hyperaminoaciduria. This work led us to quantify the respective importance of the major pathway and minor pathways of galactose in the rat after a galactose-rich diet.
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PMID:Metabolic studies of a sustained galactose overload in rat. 282 61

There are conflicting reports in the literature regarding the role of partial deficiency of "galactosemic" enzymes (galactose-1-P-urydil transferase and galactokinase) in the development of infantile and presenile cataract. The AA. have investigated the levels of Red Blood Cell Galactose-1-P-urydil transferase in 39 cataractous patients and in 22 age matched controls. A weak correlation between the enzymatic activity deficiency and the presenile cataract has been identified. The results suggest that a chronic impairment of galactose metabolism may be a contributory risk factor in the pathogenesis of presenile cataracts; however, further investigations are required to assess the actual significance of the findings of the present paper.
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PMID:Red blood cells galactose-1-P-urydil transferase in senile and presenile cataracts. 283 94

Galactosemia is a disorder caused by a deficiency of any one of three possible enzymes involved in the metabolism of galactose: galactokinase, transferase or epimerase. Any single deficient enzyme can result in cataract through the accumulation of galactitol in the lens. The ophthalmologist may play an important role in this disease, since early recognition of cataract development followed by the initiation of a galactose-free diet may lead to clearing of lenticular opacities. The clinical and laboratory findings that distinguish the three enzyme deficiency disorders of galactosemia are discussed. The biochemical genetics of each enzyme also are reviewed, along with the recent evidence linking heterozygous galactokinase deficiency and presenile cataract.
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PMID:Galactose and cataract. 304 41

Autosomal recessive inheritance of juvenile cataract is described amongst several related sibships of Lehrerleut Hutterites. The main features of the cataract include onset between three and seven years of age; rapid progression to maturity within one to three months; normal intelligence; no systemic associations, and no urinary reducing substances and normal erythrocyte galactokinase activity. Genetic analysis demonstrates the close relationship between parents of affected sibships with a coefficient of inbreeding of affected sibships of 0.0512. Estimates of heterozygote frequency within Lehrerleut Hutterites at 0.128 indicate that if current inbreeding practice continues additional cases can be expected.
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PMID:Autosomal recessive juvenile cataract in Hutterites. 365 38

The role of heterozygous galactokinase deficiency in the development of presenile cataracts is presently undetermined. Erythrocyte galactokinase activity was measured from 95 normal Caucasian subjects and from 39 Caucasian patients who had developed idiopathic bilateral cataracts between ages 20 and 55. The diagnosis of heterozygous galactokinase deficiency was based on the following criteria: galactokinase activity more than 2.0 SD below the control population mean; when available, familial evidence for heterozygous galactokinase activity was used as additional evidence. Three of 39 patients (1/13) with cataracts were found to be carriers of the galactokinase deficiency allele (P less than 0.001). Two heterozygotes had high dietary galactose intake suggesting a possible relationship between a high galactose diet and cataract formation. Dietary information was unavailable for the third heterozygote. We conclude that there is a high prevalence of heterozygous galactokinase deficiency existing in patients less than 55 yr of age with cataracts, and recommend that adults at risk restrict their consumption of dairy products.
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PMID:Cataracts in patients heterozygous for galactokinase deficiency. 394 70

Ninety-four consecutive patients admitted for elective cataract surgery were prospectively examined for erythrocyte galactokinase activity. The presumed etiology for the cataract was established by history and physical examination in 51 patients (21 were diabetic). The cataract was classified as idiopathic in 43 patients. Galactokinase activity was significantly lower in idiopathic vs. presumed (nondiabetic) etiology patients 50 years of age or younger (P less than 0.05) and in idiopathic cataract patients 50 years of age or younger vs. those older than 51 years of age (P = 0.0033). Three of the idiopathic cataract patients (6.9%) had galactokinase levels less than two standard deviations below the mean galactokinase level for age-matched patients with suspected (nondiabetic) etiology. Compared with the expected distribution for the heterozygote in the general population (0.2%), this was highly significant (P = 0.0001). Diminished galactokinase activity may increase the risk of developing presenile cataracts requiring surgery by the fourth decade.
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PMID:Galactokinase activity in patients with idiopathic cataracts. 395 27


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