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991.
Nestorowicz A; Glaser B; Wilson BA; Shyng SL; Nichols CG; Stanley CA; Thornton PS; Permutt MA 《Human molecular genetics》1998,7(7):1119-1128
Familial hyperinsulinism (HI) is a disorder characterized by dysregulation
of insulin secretion and profound hypoglycemia. Mutations in both the
Kir6.2 and sulfonylurea receptor (SUR1) genes have been associated with the
autosomal recessive form of this disorder. In this study, the spectrum and
frequency of SUR1 mutations in HI and their significance to clinical
manifestations of the disease were investigated by screening 45 HI probands
of various ethnic origins for mutations in the SUR1 gene. Single-strand
conformation polymorphism (SSCP) and nucleotide sequence analyses of
genomic DNA revealed a total of 17 novel and three previously described
mutations in SUR1 . The novel mutations comprised one nonsense and 10
missense mutations, two deletions, three mutations in consensus splice-site
sequences and an in- frame insertion of six nucleotides. One mutation
occurred in the first nucleotide binding domain (NBF-1) of the SUR1
molecule and another eight mutations were located in the second nucleotide
binding domain (NBF-2), including two at highly conserved amino acid
residues within the Walker A sequence motif. The majority of the remaining
mutations was distributed throughout the three putative transmembrane
domains of the SUR1 protein. With the exception of the 3993-9G-->A
mutation, which was detected on 4.5% (4/88) disease chromosomes, allelic
frequencies for the identified mutations varied between 1.1 and 2.3% for HI
chromosomes, indicating that each mutation was rare within the patient
cohort. The clinical manifestations of HI in those patients homozygous for
mutations in the SUR1 gene are described. In contrast with the allelic
homogeneity of HI previously described in Ashkenazi Jewish patients, these
findings suggest that a large degree of allelic heterogeneity at the SUR1
locus exists in non-Ashkenazi HI patients. These data have important
implications for genetic counseling and prenatal diagnosis of HI, and also
provide a basis to further elucidate the molecular mechanisms underlying
the pathophysiology of this disease.
相似文献
992.
Measured haplotype analysis of the angiotensin-I converting enzyme gene 总被引:20,自引:5,他引:20
Keavney B; McKenzie CA; Connell JM; Julier C; Ratcliffe PJ; Sobel E; Lathrop M; Farrall M 《Human molecular genetics》1998,7(11):1745-1751
Linkage and segregation analysis have shown that circulating angiotensin-I
converting enzyme (ACE) levels are influenced by a major quantitative trait
locus that maps within or close to the ACE gene. The D variant of a 287 bp
insertion/deletion (I/D) polymorphism in intron 16 of the gene is
associated with high ACE levels and may also be related to increased risk
of cardiovascular disease. Multiple variants that are in linkage
disequilibrium with the I/D polymorphism have been described, but it is
unknown if any of these are directly implicated, alone or in combination
with as yet undiscovered variants, in the determination of ACE levels. An
analysis of 10 polymorphisms spanning 26 kb of the ACE gene revealed a
limited number of haplotypes in Caucasian British families due to strong
linkage disequilibrium operating over this small chromosomal region. A
haplotype tree (cladogram) was constructed with three main branches (clades
A-C) which account for 90% of the observed haplotypes. Clade C is most
likely derived from clades A and B following an ancestral recombination
event. This evolutionary information was then used to direct a series of
nested, measured haplotype analyses that excluded upstream sequences,
including the ACE promoter, from harbouring the major ACE-linked variant
that explains 36% of the total trait variability. Residual familial
correlations were highly significant, suggesting the influence of
additional unlinked genes. Our results demonstrate that a combined
cladistic/measured haplotype analysis of polymorphisms within a gene
provides a powerful means to localize variants that directly influence a
quantitative trait.
相似文献
993.
世界卫生组织与热带病防治 总被引:1,自引:0,他引:1
简述世界卫生组织之缘起、架构、工作、人事及各区域分署等,及其热带病,例如疟疾、血吸虫、丝虫病、登革热、黑热病、麻风及锥虫病的防治状况。 相似文献
994.
995.
FA Riordan O Marzouk AP Thomson JA Sills CA Hart 《Archives of disease in childhood》1996,75(5):453-454
Interleukin-10 (IL-10), an anti-inflammatory cytokine, was measured in 131 children with meningococcal disease. IL-10 concentrations were significantly higher in children who died and correlated positively with proinflammatory cytokines. Children who die from meningococcal disease have high IL-10 concentrations, which do not suppress proinflammatory cytokines. 相似文献
996.
AM Shata JB Coulter CM Parry G Ching'ani RL Broadhead CA Hart 《Archives of disease in childhood》1996,74(6):535-537
Confirmation of tuberculosis in young children is difficult as they seldom expectorate sputum. Gastric aspirates are invasive and stressful and like laryngeal swabs are seldom smear positive. Induction of sputum by nebulised hypertonic saline (3%) was attempted in 30 Malawian children aged 3-15 years and was successful in 29. Four sputa were smear positive and Mycobacterium tuberculosis was cultured from three of them. A further four sputa were culture positive though smear negative. In all, the diagnosis of tuberculosis was confirmed in eight (28%) of 29 children. The presence of polymorphonuclear cells in the specimen was indicative of sputum, in contrast to epithelial cells which originate from saliva. A predominance of polymorphonuclear cells in specimens was more common in older children and these specimens were more likely to be smear positive or culture positive. Sputum induction is a useful method for the confirmation of tuberculosis and is possible in young children. 相似文献
997.
998.
ED Primrose JM Savage CA Boreham GW Cran JJ Strain 《Archives of disease in childhood》1994,71(3):239-242
Hypercholesterolaemia is a major risk factor for the development of coronary heart disease (CHD). Early detection and management of hypercholesterolaemia could retard the atherosclerotic process. Given that CHD and hypercholesterolaemia cluster within families, a screening strategy based on a family history of vascular disease has been advocated. Serum total cholesterol concentrations were measured in a random stratified sample of 1012 children aged from 12-15 years old participating in a coronary risk factor surveillance study in Northern Ireland. Information about vascular disease in close family members was obtained by means of a questionnaire. The study population was divided into two groups according to total cholesterol values: (i) normal, < 5.2 mmol/l (n = 822) and (ii) raised, > or = 5.2 mmol/l (n = 190). A family history identified 63 out of 190 individuals with hypercholesterolaemia yielding a sensitivity of 33.2% and specificity of 71.5%. Our data indicated that a strategy whereby only children from high risk families are screened for hypercholesterolaemia is ineffective. While primary prevention emphasising a healthy diet for all is essential, the role of universal screening deserves further appraisal. 相似文献
999.
To determine the biological significance of high concentrations of non-haem iron in the livers of infants dying from sudden infant death syndrome (SIDS), liver samples were obtained at necropsy from 66 infants who died from SIDS and 28 control infants who died before 2.5 years of age. All were full term deliveries. Liver iron concentrations decreased rapidly with age in the two groups. Liver iron concentrations in the SIDS infants and controls were compared for those infants who died between 1 month and 1 year of age. The median liver iron concentration in the SIDS infants was 296 micrograms/g wet weight; significantly higher than the median of 105 micrograms/g in controls. There was an inverse relation between iron concentration and age in the two groups, but an analysis of covariance confirmed the significantly lower values in controls. The frequency (22%) of HLA-A3 in SIDS infants was similar to that expected for the United Kingdom population (25%) and does not implicate the gene for haemochromatosis as a cause of high liver iron concentrations. These findings show that the peak incidence of SIDS occurs when mean concentrations of iron in liver tissue are higher than at any other time of life. Although a primary causal connection seems unlikely, high tissue iron concentrations may lower resistance to infection and enhance free radical formation, leading to tissue damage. 相似文献
1000.