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Reference
Complete the bibliographic reference for the article according to AJE format.
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Cardoso C, Oliveira P, Porto G, Oberkanins C, Mascarenhas M, Rodrigues P, Kury F, de Sousa M. Comparative study of the two more frequent HFE mutations (C282Y and H63D): significant different allelic frequencies between the North and South of Portugal. Eur Hum Gene. 2001 9:843- 8. |
Category of HuGE information
Specify the types of information (from the list below) available in the article:
- Prevalence of gene variant
- Gene-disease association
- Gene-environment interaction
- Gene-gene interaction
- Genetic test evaluation/monitoring
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- Prevalence of gene variant
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Study hypotheses or purpose
The authors study hypotheses or main purpose for conducting the study.
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Hypothesis: To “estimate the frequency of the C282Y and H63D HFE mutations in Portugal , comparing its distribution through different regions.” |
Gene(s)
Identification of the following:
- Gene name
- Chromosome location
- Gene product/function
- Alleles
- OMIM #
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- Gene: HFE
- Chromosome location: 6p22.1
- Gene product/function: The gene product of HFE decreases cellular acquisition of iron from the transferrin receptor within the endocytic compartments.
- Alleles: C282Y, H63D
- OMIM #: 235200
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Environmental factor(s)
Identification of the major environmental factors studied (infectious, chemical, physical, nutritional, and behavioral)
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N/A |
Health outcome(s)
Identification of the major health outcome(s) studied
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N/A |
Study design
Specification of the type of study design(s)
- Case-control
- Cohort
- Cross-sectional
- Descriptive or case series
- Clinical trial
- Population screening
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6. Population screening |
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Cohort definition
For study designs 2, 3, and 6, the following are defined, where available:
- Cohort selection criteria
- Exclusion criteria
- Gender
- Race/ethnicity
- Age
- Time period
- Geographic location
- Number of participants
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- Cohort selection criteria: Dried blood spots were collected from 95% of newborns in Portugal for neonatal screening. Blood spot specimens for this study were chosen at random from the five geographic regions of Portugal .
- Exclusion criteria: None
- Gender: N/A
- Race/ethnicity: N/A
- Age: N/A
- Time period: Not specified
- Geographic location: Portugal is divided into five geographic regions: North, Center, Lisbon and the Tagus Valley , Alentejo, and Algarve. Samples were randomly selected from each of these five regions.
- Number of participants: 640 samples were used in this study. 129 from the North, 130 from the Center, 133 from Lisbon and the Tagus valley, 132 from the Alentejo, and 116 from the Algarve.
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Assessment of environment factors
For studies that include gene-environment interactions, define the following, if available:
- Environmental factor
- Exposure assessment
- Exposure definition
- Number of participants with exposure data (%
of total eligible)
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N/A |
Genotyping
Specify the following:
- Gene
- DNA source
- Methodology
- Number of participants genotyped (% of total eligible)
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- Gene: HFE
- DNA source: Dried blood spots
- Methodology: DNA was purified using the InstaGene Dry Blood Kit (Bio-Rad Laboratories). Haemochromatosis Gene Mutation Assay I and II kits (Vienna-lab, Vienna , Austria ) were used to genotype the specimens for HFE. Each sample was PCR amplified in vitro and terminally labeled with fluorescein. The amplified products were hybridized with allele-specific oligonucleotides to determine the genotype of each specimen.
- Number of Participants genotyped: 100%
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Results
Describe the major results under each of the following HuGE categories. Include tables when data are provided:
- Prevalence of gene variant
- Gene-disease association
- Gene-environment interaction
- Gene-gene interaction
- Genetic test evaluation/monitoring
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1. Prevalence of Gene Variant:
HFE Genotype |
North n=129 |
Center n=130 |
Lisbon and Tagus Valley n=133 |
Alentejo n=132 |
Algarve n=116 |
C282Y/C282Y |
1 |
1 |
0 |
0 |
0 |
C282Y/wt |
10 |
5 |
7 |
5 |
0 |
C282Y/H63D |
3 |
5 |
1 |
1 |
2 |
H63D/wt |
31 |
35 |
27 |
37 |
23 |
H63D/H63D |
8 |
6 |
6 |
5 |
7 |
wt/wt |
76 |
78 |
92 |
84 |
84 |
C282Y allelic frequency |
0.058 |
0.046 |
0.030 |
0.023 |
0.009 |
95% CI |
0.033-0.095 |
0.024-0.079 |
0.013-0.058 |
0.008-0.049 |
0.001-0.031 |
H63D allelic frequency |
0.194 |
0.200 |
0.150 |
0.182 |
0.168 |
95% CI |
0.151-0.247 |
0.152-0.250 |
03112-0.200 |
0.140-0.233 |
0.126-0.221 |
2. Genotype Prevalences:
HFE Genotype |
North n=129 |
Center n=130 |
Lisbon and Tagus Valley n=133 |
Alentejo n=132 |
Algarve n=116 |
Portugal n=640 |
C282Y/C282Y |
0.78% |
0.77% |
0 |
0 |
0 |
0.31% |
C282Y/wt |
7.75% |
3.85% |
5.26% |
3.79% |
0 |
4.22% |
C282Y/H63D |
2.33% |
3.85% |
0.75% |
0.76% |
1.72% |
1.88% |
H63D/wt |
24.03% |
26.92% |
20.30% |
28.03% |
19.83% |
23.91% |
H63D/H63D |
6.20% |
4.62% |
4.51% |
3.79% |
6.03% |
5.00% |
wt/wt |
58.91% |
60.0% |
69.17% |
63.64% |
72.41% |
64.69% |
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Conclusion
State the author's overall conclusions from the study |
The C282Y mutation of the HFE gene was more frequent in the northern regions of Portugal and less frequent in the southern regions. The H63D mutation is evenly distributed throughout the country.
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Comments
Provide additional insight, including methodologic issues and/or concerns about the study
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The authors did not provide enough information to evaluate the statistical analysis presented in the paper. Some analysis was done with small numbers; thus the estimates may be unstable. |
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