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)

Two male subjects are described, with unusual clinical presentations and with hitherto undescribed G6PD variants. The first, of Italian extraction, suffered from severe neonatal jaundice following maternal ingestion of fresh broad beans (Vicia fava) both prenatally and postnatally: the expression of the enzymatic defect was much more severe in the neonatal period than on retesting in adolescence, when biochemical characterization showed unique features which justify designation as a new variant Gd(+) Alexandra. The second patient, a boy of Maltese extraction who was found to have bilateral lamellar cataracts at the age of 4 years, was identified as G6PD deficient only as a result of a survey of children of Mediterranean origin with unexplained cataract formation; he has approximately 15% of normal enzyme activity, with another unique combination of biochemical characteristics which has led to its designation as Gd(-) Camperdown. Although this association may be coincidental, it prompts further attention to the possibility that under certain circumstances G6PD deficiency may favor cataract formation. The two cases illustrate the value of characterization of the mutant enzyme whenever unexpected clinical or laboratory results are obtained.
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PMID:Glucose 6-phosphate dehydrogenase variants: Gd (+) Alexandra associated with neonatal jaundice and Gd (-) Camperdown in a young man with lamellar cataracts. 2 2

The G6PD activity of erythrocytes in 113 male patients with senile and presenile cataract and 86 controls, and G6PD activity of lens in 30 patients with senile cataract and 42 controls were reported. The cataractous group had higher frequency of G6PD deficiency and lower average G6PD level in erythrocytes and lenses, but without statistical significance. The frequency of G6PD deficiency of erythrocytes in presenile cataractous group was higher than that of senile cataractous group but with no statistical significance too. However, the average G6PD level of erythrocytes in presenile cataractous group was lower than that of senile cataractous group and with statistical significance (P < 0.05). The G6PD activity of lenses only presenile in the cortex and have a positive correlation with that of erythrocytes. There was a case with deficiency of G6PD both of erythrocytes and cataractous lenses in both eyes. The results indicate that the deficiency of G6PD might be one of the cataractous pathogenetic factor for presenile cataract. Measurement of G6PD activity of erythrocytes among population might be of significance in finding the risk factor for cataract.
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PMID:The study of G6PD in erythrocyte and lens in senile and presenile cataract. 128 74

G6PD deficiency may render afflicted individuals more susceptible to certain degenerative diseases. To clarify the relationship between G6PD deficiency and cataract, blood G6PD activity was determined in patients with cataract in Taiwan. The cases and hospital-based controls were recruited from the medical outpatient department and from the physical checkup department at Chang Gung Memorial Hospital, respectively. A questionnaire survey was used to determine associations between cataracts and their risk factors. G6PD activity in fresh RBC was quantitatively measured and genomic DNA was extracted from lymphocyte nuclei. The mean blood G6PD activity among cataract patients (278.1 U/10[12] RBC) was similar to that of normals (288.0 U/10[12] RBC). No statistically significant difference in the distribution of G6PD activities as grouped by an increment of 100 U/[10, 12] RBC was observed between cataract patients and normal subjects. The predominant forms of G6PD gene mutation (cDNA 1376 G to T and 95 A to G) were both found in the patients with cataract. The adjusted odds ratio for cataract was 1.21 for every decrement of 100 U/10[12] RBC of G6PD activity in these subjects. These data indicate that G6PD activity is not a potential risk factor for senile cataract in Taiwan.
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PMID:Decreased glucose-6-phosphate-dehydrogenase (G6PD) activity and risk of senile cataract in Taiwan. 1658 14

Chronic hyperglycemia causes increased level of reactive oxygen species which is thought to be involved in the pathogenesis of diabetes associated complications including cataract. In diabetic cataractous lens, over production of free radicals and decreased capacity of antioxidant defense system are the major contributors to oxidative damage by polyol pathway and advanced glycation end products. The current study focused on analysis of factors associated with osmotic imbalance and oxidative stress in aging and diabetic human cataractous lenses. We examined activities of polyol pathway enzymes, G6PD and glutathione system in lenses from subjects suffering from cataract due to aging and diabetes. We observed elevated activities of aldose reductase and sorbitol dehydrogenase while G6PD and glutathione system enzyme activities were found to be lower in cataractous subjects suffering from diabetes. The findings from the current study support the premise that osmotic imbalance, AGEs formation and oxidative stress contribute synergistically to the development of lens opacity in hyperglycemia.
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PMID:Osmotic stress induced oxidative damage: possible mechanism of cataract formation in diabetes. 2260 18

Malaria is one of the most common diseases in the African population. Genetic variance in glucose dehydrogenase 6-phosphate (G6PD) in humans determines the response to malaria exposure. In this study, we aimed to analyze the frequency of two single-nucleotide polymorphisms (G202A and A376G) present in two local tribes of Sudanese Arabs from the region of the 4th Nile cataract in Sudan, the Shagia and Manasir. The polymorphisms in G6PD were analyzed in 217 individuals (126 representatives of the Shagia tribe and 91 of the Manasir tribe). Real-time PCR and RFLP-PCR were utilized to analyze significant differences in the prevalence of alleles and genotypes. The 202A G6P allele frequency was 0.7%, whereas the G202 variant was found in 93.3% of cases. The AA, GA, and GG genotype frequencies for the A376G G6PD codon among the Shagia were 88, 11.1, and 0.9%, respectively; this is similar to the distribution among Manasir tribe representatives (94.5, 3.3, and 2.2%, respectively; OR 3.44 [0.85-16.17], p=0.6). Notably, in north-eastern Sudan the G6PD B (202G/376A) compound genotype frequency was 90.3%, whereas the G6PD A variant (202G/376G) was found in 1.4% of that population. Identification of the G6PD A- variant (202A/376G) in the isolated Shagia tribe provides important information regarding the tribal ancestry. Taken together, the data presented in this study suggest that the Shagia tribe was still nomadic between 4000 and 12,000 years ago. Moreover, the lack of G6PD A- genotype among ethnically diverse Monasir tribesmen indicates a separation of the Shagia from the other tribes in the region of the 4th Nile cataract in Sudan.
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PMID:Analysis of the genetic variants of glucose-6-phosphate dehydrogenase in inhabitants of the 4th Nile cataract region in Sudan. 2314 19

Autosomal dominant congenital cataract (ADCC), the most common hereditary disease, is a major cause of eye disease in children. Due to its high genetic and clinical heterogeneity, the identification of ADCC-associated gene mutations is essential for the development of molecular therapies. In this study, we examined a four-generation Chinese pedigree with ADCC and identified putative mutations in ADCC candidate genes via next-generation sequencing (NGS) followed by Sanger sequencing. A novel missense mutation in GJA8 (c.T217C) in ADCC patients causes a serine-to-proline substitution at residue 73 of connexin 50 (Cx50); no mutation was found in unaffected family members and unrelated healthy individuals. Functional analysis revealed that this missense mutation disrupts protein function in human lens epithelial cells (HLEpiCs), which fails to form calcium-sensitive hemichannels. Furthermore, mutant Cx50 leads to decreased ROS scavenging by inhibiting G6PD expression and thus induces cell apoptosis via aberrant activation of the unfolded protein response (UPR). In conclusion, we report a novel GJA8 heterozygous mutation in a Chinese family with a vital role in ADCC, broadening the genetic spectrum of this disease.
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PMID:GJA8 missense mutation disrupts hemichannels and induces cell apoptosis in human lens epithelial cells. 3184 91