Prevalence of iron deficiency in 62,685 women of seven race/ethnicity groups: The HEIRS Study.

BACKGROUND: Few cross-sectional studies report iron deficiency (ID) prevalence in women of different race/ethnicity and ages in US or Canada. MATERIALS AND METHODS: We evaluated screening observations on women who participated between 2001-2003 in a cross-sectional, primary care-based sample of adults ages ≥25 y whose observations were complete: race/ethnicity; age; transferrin saturation; serum ferritin; and HFE p.C282Y and p.H63D alleles. We defined ID using a stringent criterion: combined transferrin saturation <10% and serum ferritin <33.7 pmol/L (<15 µg/L). We compared ID prevalence in women of different race/ethnicity subgrouped by age and determined associations of p.C282Y and p.H63D to ID overall, and to ID in women ages 25-44 y with or without self-reported pregnancy. RESULTS: These 62,685 women included 27,079 whites, 17,272 blacks, 8,566 Hispanics, 7,615 Asians, 449 Pacific Islanders, 441 Native Americans, and 1,263 participants of other race/ethnicity. Proportions of women with ID were higher in Hispanics and blacks than whites and Asians. Prevalence of ID was significantly greater in women ages 25-54 y of all race/ethnicity groups than women ages ≥55 y of corresponding race/ethnicity. In women ages ≥55 y, ID prevalence did not differ significantly across race/ethnicity. p.C282Y and p.H63D prevalence did not differ significantly in women with or without ID, regardless of race/ethnicity, age subgroup, or pregnancy. CONCLUSIONS: ID prevalence was greater in Hispanic and black than white and Asian women ages 25-54 y. p.C282Y and p.H63D prevalence did not differ significantly in women with or without ID, regardless of race/ethnicity, age subgroup, or pregnancy.

Next generation analytic tools for large scale genetic epidemiology studies of complex diseases.

Over the past several years, genome-wide association studies (GWAS) have succeeded in identifying hundreds of genetic markers associated with common diseases. However, most of these markers confer relatively small increments of risk and explain only a small proportion of familial clustering. To identify obstacles to future progress in genetic epidemiology research and provide recommendations to NIH for overcoming these barriers, the National Cancer Institute sponsored a workshop entitled "Next Generation Analytic Tools for Large-Scale Genetic Epidemiology Studies of Complex Diseases" on September 15-16, 2010. The goal of the workshop was to facilitate discussions on (1) statistical strategies and methods to efficiently identify genetic and environmental factors contributing to the risk of complex disease; and (2) how to develop, apply, and evaluate these strategies for the design, analysis, and interpretation of large-scale complex disease association studies in order to guide NIH in setting the future agenda in this area of research. The workshop was organized as a series of short presentations covering scientific (gene-gene and gene-environment interaction, complex phenotypes, and rare variants and next generation sequencing) and methodological (simulation modeling and computational resources and data management) topic areas. Specific needs to advance the field were identified during each session and are summarized.

Quality control and quality assurance in genotypic data for genome-wide association studies.

Genome-wide scans of nucleotide variation in human subjects are providing an increasing number of replicated associations with complex disease traits. Most of the variants detected have small effects and, collectively, they account for a small fraction of the total genetic variance. Very large sample sizes are required to identify and validate findings. In this situation, even small sources of systematic or random error can cause spurious results or obscure real effects. The need for careful attention to data quality has been appreciated for some time in this field, and a number of strategies for quality control and quality assurance (QC/QA) have been developed. Here we extend these methods and describe a system of QC/QA for genotypic data in genome-wide association studies (GWAS). This system includes some new approaches that (1) combine analysis of allelic probe intensities and called genotypes to distinguish gender misidentification from sex chromosome aberrations, (2) detect autosomal chromosome aberrations that may affect genotype calling accuracy, (3) infer DNA sample quality from relatedness and allelic intensities, (4) use duplicate concordance to infer SNP quality, (5) detect genotyping artifacts from dependence of Hardy-Weinberg equilibrium test P-values on allelic frequency, and (6) demonstrate sensitivity of principal components analysis to SNP selection. The methods are illustrated with examples from the "Gene Environment Association Studies" (GENEVA) program. The results suggest several recommendations for QC/QA in the design and execution of GWAS.

Heritability of serum iron measures in the hemochromatosis and iron overload screening (HEIRS) family study.

Heritability is the proportion of observed variation in a trait among individuals in a population that is attributable to hereditary factors. The Hemochromatosis and Iron Overload Screening family study estimated heritability of serum iron measures. Probands were HFE C282Y homozygotes or non-C282Y homozygotes with elevated transferrin saturation (TS > 50%, men; TS > 45%, women) and serum ferritin concentration (SF > 300 microg/L, men; SF > 200 microg/L, women). Heritability (h(2)) was estimated by variance component analysis of TS, natural logarithm (ln) of SF, and unsaturated iron-binding capacity (UIBC). Participants (N = 942) were 77% Caucasians, 10% Asians, 8% Hispanics, and 5% other race/ethnicities. Average age (SD) was 49 (16) years; 57% were female. For HFE C282Y homozygote probands and their family members, excluding variation due to HFE C282Y and H63D genotype and measured demographic and environmental factors, the residual h(2) (SE) was 0.21 (0.07) for TS, 0.37 (0.08) for ln SF, and 0.34 (0.08) for UIBC (all P < 0.0004 for comparisons with zero). For the non-C282Y homozygote proband group, residual h(2) was significant with a value of 0.64 (0.26) for ln SF (P = 0.0096). In conclusion, serum iron measures have significant heritability components, after excluding known genetic and nongenetic sources of variation.

Screening for iron overload: lessons from the hemochromatosis and iron overload screening (HEIRS) study.

BACKGROUND: The HEmochromatosis and IRon Overload Screening (HEIRS) Study provided data on a racially, ethnically and geographically diverse cohort of participants in North America screened from primary care populations. METHODS: A total of 101,168 participants were screened by testing for HFE C282Y and H63D mutations, and measuring serum ferritin concentration and transferrin saturation. In the present review, lessons from the HEIRS Study are highlighted in the context of the principles of screening for a medical disease as previously outlined by the World Health Organization. RESULTS: Genetic testing is well accepted, with minimal risk of discrimination. Transferrin saturation has high biological variability and relatively low sensitivity to detect HFE C282Y homozygotes, which limits its role as a screening test. Symptoms attributable to HFE C282Y homozygosity are no more common in individuals identified by population screening than in control subjects. CONCLUSIONS: Generalized population screening in a primary care population as performed in the HEIRS Study is not recommended. There may be a role for focused screening in Caucasian men, with some debate regarding genotyping followed by phenotyping, or phenotyping followed by genotyping.

Potential nonresponse bias in a clinical examination after initial screening using iron phenotyping and HFE genotyping in the hemochromatosis and iron overload screening study.

BACKGROUND: Little is known about the factors affecting participation in clinical assessments after HEmochromatosis and IRon Overload Screening. METHODS: Initial screening of 101,168 primary care patients in the HEmochromatosis and IRon Overload Screening study was performed using serum iron measures and hemochromatosis gene (HFE) genotyping. Using iron phenotypes and HFE genotypes, we identified 2256 cases and 1232 controls eligible to participate in a clinical examination. To assess the potential for nonresponse bias, we compared the sociodemographic, health status, and attitudinal characteristics of participants and nonparticipants using adjusted odds ratios (ORs) and 95% confidence interval (CI). RESULTS: Overall participation was 74% in cases and 52% in controls; in both groups, participation was highest at a health maintenance organization and lowest among those under 45 years of age (cases: OR = 0.68; 95% CI 0.53, 0.87; controls: OR = 0.59; 95% CI 0.44, 0.78). In controls only, participation was also lower among those over 65 years of age than the reference group aged 46-64 (OR = 0.64; 95% CI 0.47, 0.88). Among cases, participation was higher in HFE C282Y homozygotes (OR = 3.98; 95% CI 2.60, 6.09), H63D homozygotes (OR = 2.79; 95% CI 1.23, 6.32), and C282Y/H63D compound heterozygotes (OR = 1.82; 95% CI 1.03, 3.22) than in other genotypes, and lower among non-Caucasians and those who preferred a non-English language than in Caucasians and those who preferred English (p < 0.0001). CONCLUSIONS: Subjects with greatest risk to have iron overload (C282Y homozygotes; cases > or =45 years; Caucasians) were more likely to participate in a postscreening clinical examination than other subjects. We detected no evidence of strong selection bias.

Accuracy of family history of hemochromatosis or iron overload: the hemochromatosis and iron overload screening study.

BACKGROUND & AIMS: The aim of this study was to assess the analytic validity of self-reported family history of hemochromatosis or iron overload. METHODS: A total of 141 probands, 549 family members, and 641 controls participated in the primary care Hemochromatosis and Iron Overload Screening Study. Participants received a postscreening clinical examination and completed questionnaires about personal and family histories of hemochromatosis or iron overload, arthritis, diabetes, liver disease, and heart disease. We evaluated sensitivities and specificities of proband-reported family history, and concordance of HFE genotype C282Y/C282Y in probands and siblings who reported having hemochromatosis or iron overload. RESULTS: The sensitivities of proband-reported family history ranged from 81.4% for hemochromatosis or iron overload to 18.4% for liver disease; specificities for diabetes, liver disease, and heart disease were greater than 94%. Hemochromatosis or iron overload was associated with a positive family history across all racial/ethnic groups in the study (odds ratio, 14.53; 95% confidence intervals, 7.41-28.49; P < .0001) and among Caucasians (odds ratio, 16.98; 95% confidence intervals, 7.53-38.32; P < .0001). There was 100% concordance of HFE genotype C282Y/C282Y in 6 probands and 8 of their siblings who reported having hemochromatosis or iron overload. CONCLUSIONS: Self-reported family history of hemochromatosis or iron overload can be used to identify individuals whose risk of hemochromatosis or iron overload and associated conditions is increased. These individuals could benefit from further evaluation with iron phenotyping and HFE mutation analysis.

Serum ferritin concentrations and body iron stores in a multicenter, multiethnic primary-care population.

How often elevated serum ferritin in primary-care patients reflects increased iron stores (normally 0.8 g in men, 0.4 g in women) is not known. The Hereditary Hemochromatosis and Iron Overload Screening (HEIRS) study screened 101,168 primary-care participants (44% Caucasians, 27% African-Americans, 14% Asians/Pacific Islanders, 13% Hispanics, 2% others). Follow-up clinical evaluation was performed in 302 of 333 HFE C282Y homozygotes regardless of iron measures and 1,375 of 1,920 nonhomozygotes with serum ferritin >300 microg/L (men), >200 microg/L (women) and transferrin saturation >50% (men), >45% (women). Quantitative phlebotomy was conducted in 122 of 175 C282Y homozygotes and 122 of 1,102 nonhomozygotes with non-transfusional serum ferritin elevation at evaluation. The estimated prevalence in the Caucasian population of C282Y homozygotes with serum ferritin >900 microg/L at evaluation was 20 per 10,000 men and 4 per 10,000 women; this constellation was predictive of iron stores >4 g in men and >2 g in women. The estimated prevalence per 10,000 of non-C282Y homozygotes with serum ferritin >900 microg/L at evaluation was 7 among Caucasians, 13 among Hispanics, 20 among African Americans, and 38 among Asians and Pacific Islanders, and this constellation was predictive of iron stores >2 g but <4 g. In conclusion, serum ferritin >900 microg/L after initial elevations of both serum ferritin and transferrin saturation is predictive of mildly increased iron stores in multiple ethnic populations regardless of HFE genotype. Serum ferritin >900 microg/L in male C282Y homozygotes is predictive of moderately increased iron stores.

Positive, negative, and disparate--women's differing long-term psychosocial experiences of bilateral or contralateral prophylactic mastectomy.

Because of recent studies showing strong prevention benefit and acceptable psychosocial outcomes, more women may be considering prophylactic mastectomy. A growing literature shows some positive psychosocial outcomes for women with bilateral prophylactic mastectomy, but less is known about women with contralateral prophylactic mastectomy. Several surveys have shown that a large majority of women with prophylactic mastectomy report satisfaction with their decisions to have the procedure when asked in a quantitative, closed-ended format. We sought to explore the nuances of women's satisfaction with the procedure using a qualitative, open-ended format. We included open-ended questions as part of a mailed survey on psychosocial outcomes of prophylactic mastectomy. The research team coded and analyzed these responses using qualitative methods. We used simple descriptive statistics to compare the demographics of the entire survey sample to those women who answered the open-ended questions; the responses to the open- and closed-ended satisfaction questions, and the responses of women with bilateral and contralateral prophylactic mastectomy. Seventy-one percent of women with prophylactic mastectomy responded to the survey and 48% provided open-ended responses about psychosocial outcomes. Women's open-ended responses regarding psychosocial outcomes could be coded into one of three general categories--positive, negative, and disparate. In the subgroup of women with both open- and closed-ended responses, over 70% of women providing negative and disparate comments to the open-ended question simultaneously indicated satisfaction on a closed-ended question. Negative and disparate open-ended responses were twice as common among women with bilateral prophylactic mastectomy (52%) than women with contralateral prophylactic mastectomy (26%). These findings suggest that even among women who report general satisfaction with their decision to have prophylactic mastectomy via closed-ended survey questions, lingering negative psychosocial outcomes can remain, particularly among women with bilateral prophylactic mastectomy. This dichotomy could be an important factor to discuss in counseling women considering the procedure.

Bivariate mixture modeling of transferrin saturation and serum ferritin concentration in Asians, African Americans, Hispanics, and whites in the Hemochromatosis and Iron Overload Screening (HEIRS) Study.

Bivariate mixture modeling was used to analyze joint population distributions of transferrin saturation (TS) and serum ferritin concentration (SF) measured in the Hemochromatosis and Iron Overload Screening (HEIRS) Study. Four components (C1, C2, C3, and C4) with successively age-adjusted increasing means for TS and SF were identified in data from 26,832 African Americans, 12,620 Asians, 12,264 Hispanics, and 43,254 whites. The largest component, C2, had normal mean TS (21% to 26% for women, 29% to 30% for men) and SF (43-82 microg/L for women, 165-242 microg/L for men), which consisted of component proportions greater than 0.59 for women and greater than 0.68 for men. C3 and C4 had progressively greater mean values for TS and SF with progressively lesser component proportions. C1 had mean TS values less than 16% for women (<20% for men) and SF values less than 28 microg/L for women (<47 microg/L for men). Compared with C2, adjusted odds of iron deficiency were significantly greater in C1 (14.9-47.5 for women, 60.6-3530 for men), adjusted odds of liver disease were significantly greater in C3 and C4 for African-American women and all men, and adjusted odds of any HFE mutation were increased in C3 (1.4-1.8 for women, 1.2-1.9 for men) and in C4 for Hispanic and white women (1.5 and 5.2, respectively) and men (2.8 and 4.7, respectively). Joint mixture modeling identifies a component with lesser SF and TS at risk for iron deficiency and 2 components with greater SF and TS at risk for liver disease or HFE mutations. This approach can identify populations in which hereditary or acquired factors influence metabolism measurement.

What women wish they knew before prophylactic mastectomy.

Although prophylactic mastectomy significantly reduces the incidence and recurrence of breast cancer, little is known about women's information needs before the procedure. We surveyed 967 women, from 6 healthcare systems, with bilateral or contralateral prophylactic mastectomy performed between 1979 and 1999. There were 2 open-ended questions: "What one thing do you wish you had known before your prophylactic mastectomy" and "Is there anything else you would like to share with us?" Three researchers categorized responses, and informational needs were ascertained. Seventy-one percent (684 women) responded, of which 81% answered one or both open-ended questions. There were 386 comments (made by 293 women) that related to information needs; 79% of women had bilateral prophylactic mastectomy and 58% had contralateral prophylactic mastectomy. Most concerns (69%) were related to reconstruction: the longevity; look and feel of implants, pain, numbness, scarring, and reconstruction options. Many women wished they had seen photographs to better prepare them for the final result. Our findings suggest that information needs of many women undergoing prophylactic mastectomy, particularly those selecting bilateral prophylactic mastectomy, have not been sufficiently addressed. Clinicians and health educators should be aware of patient needs and must counsel women accordingly.

African Americans at risk for increased iron stores or liver disease.

PURPOSE: We sought to determine the prevalence of elevated measures of iron status in African Americans and whether the combination of serum ferritin concentration >200 microg/L for women or >300 microg/L for men and transferrin saturation in the highest quartile represents increased likelihood of mutation of HFE, self-reported iron overload or self-reported liver disease. SUBJECTS AND METHODS: A cross-sectional observational study of 27,224 African Americans > or =25 years of age recruited in a primary care setting was conducted as part of the multi-center, multi-ethnic Hemochromatosis and Iron Overload Screening (HEIRS) Study. Measurements included serum ferritin concentration, transferrin saturation, testing for HFE C282Y and H63D, and self-reported iron overload and liver disease. RESULTS: Serum ferritin concentration >200 microg/L for women or >300 microg/L for men occurred in 5263 (19.3%) of African Americans, while serum ferritin concentration in this range with highest-quartile transferrin saturation (>29% women; >35% men) occurred in 1837 (6.7%). Adjusted odds of HFE mutation (1.76 women, 1.67 men), self-reported iron overload (1.97 women, 2.88 men), or self-reported liver disease (5.18 women, 3.73 men) were greater with elevated serum ferritin concentration and highest-quartile transferrin saturation than with nonelevated serum ferritin concentration (each P <.05). CONCLUSIONS: Serum ferritin concentration >200 microg/L for women or >300 microg/L for men in combination with transferrin saturation >29% for women or >35% for men occurs in approximately 7% of adult African American primary care patients. Patients with this combination of iron test results should be evaluated for increased body iron stores or liver disease.

Determinants and characteristics of mean corpuscular volume and hemoglobin concentration in white HFE C282Y homozygotes in the hemochromatosis and iron overload screening study.

Elevated mean corpuscular volume (MCV) is common in persons with hemochromatosis associated with HFE C282Y homozygosity. We evaluated data from the subset of non-Hispanic white participants in the Hemochromatosis and Iron Overload Screening Study to determine if elevated MCV in C282Y homozygotes is related to this genotype or to serum iron measures. Regression analysis was used to model MCV and Hb from transferrin saturation (TfSat), serum ferritin (SF), mean corpuscular hemoglobin concentration, red blood cell count, age, HFE genotype, Field Center, and presence of liver-related abnormalities in C282Y homozygotes and control subjects without HFE mutations (wt/wt genotype). Mean MCV was higher in C282Y homozygotes than in HFE wt/wt controls (94.4 vs. 89.7 fL in women; 95.3 vs. 91.2 fL in men; P < 0.0001 for both). These differences were largely associated with increased mean TfSat and SF in C282Y homozygotes. Adjusted mean MCV was 92.0 fL (95% confidence interval, 91.1, 92.9) in female C282Y homozygotes and 90.9 fL (90.3, 91.5) in controls. Among women with SF in the reference range 20-200 microg/L, adjusted mean MCV was 92.9 fL, (91.7, 94.2) in C282Y homozygotes, 1.8 fL higher than in controls (P = 0.013). The adjusted mean MCV of male C282Y homozygotes and controls was similar (P = 0.30). Adjusted mean Hb was 0.2 g/dL higher in women with C282Y/C282Y than in controls. Greater mean MCV in C282Y homozygosity reflects increased mean TfSat and mean SF in men and women; an additional effect of genotype on MCV and Hb was detected in women.

Serum ferritin and transferrin saturation in Asians and Pacific Islanders.

BACKGROUND: Asians and Pacific Islanders in the Hemochromatosis and Iron Overload Screening (HEIRS) Study had the highest prevalence of elevated serum ferritin (SF) and transferrin saturation (TS) levels, but to our knowledge, the reasons for this have not been investigated. METHODS: Using multiple linear regression, we compared TS and SF distributions for 42 720 Asian, Pacific Islander, and white HEIRS Study participants recruited through 5 field centers in North America who did not have HFE C282Y or H63D alleles. RESULTS: Compared with their white counterparts, Asian men had a 69-ng/mL (155-pmol/L) higher adjusted mean SF level and a 3% higher TS level (P<.001); Asian women had 23-ng/mL (52-pmol/L) higher adjusted mean SF level and a 3% higher TS level (P<.001). The mean TS level of Asian women was higher than that of Pacific Islander women, and the mean SF level of Pacific Islander men was significantly higher than that of white men. These differences remained significant after adjusting for self-reported history of diabetes or liver disease. Additional information for selected participants suggested that these differences are largely unrelated to mean corpuscular volume less than 80 fL, body mass index, or self-reported alcohol intake. Available liver biopsy and phlebotomy data indicated that iron overload is probably uncommon in Asian participants. CONCLUSION: Higher TS and SF levels in persons of Asian or Pacific Island heritage may need to be interpreted differently than for whites, although the biological basis and clinical significance of higher levels among Asians and Pacific Islanders are unclear.

Specificity of clinical breast examination in community practice.

BACKGROUND: Millions of women receive clinical breast examination (CBE) each year, as either a breast cancer screening test or a diagnostic test for breast symptoms. While screening CBE had moderately high specificity (approximately 94%) in clinical trials, community clinicians may be comparatively inexperienced and may conduct relatively brief examinations, resulting in even higher specificity but lower sensitivity. OBJECTIVE: To estimate the specificity of screening and diagnostic CBE in clinical practice and identify patient factors associated with specificity. DESIGN: Retrospective cohort study. SUBJECTS: Breast-cancer-free female health plan enrollees in 5 states (WA, OR, CA, MA, and MN) who received CBE (N = 1,484). MEASUREMENTS: Medical charts were abstracted to ascertain breast cancer risk factors, examination purpose (screening vs diagnostic), and results (true-negative vs false-positive). Women were considered "average-risk" if they had neither a family history of breast cancer nor a prior breast biopsy and "increased-risk" otherwise. RESULTS: Among average- and increased-risk women, respectively, the specificity (true-negative proportion) of screening CBE was 99.4% [95% confidence interval (CI): 98.8-99.7%] and 97.1% (95% CI: 95.7-98.0%), and the specificity of diagnostic CBE was 68.7% (95% CI: 59.7-76.5%) and 57.1% (95% CI: 51.1-63.0%). The odds of a true-negative screening CBE (specificity) were significantly lower among women at increased risk of breast cancer (adjusted odds ratio 0.21; 95% CI: 0.10-0.46). CONCLUSIONS: Screening CBE likely has higher specificity among community clinicians compared to examiners in clinical trials of breast cancer screening, even among women at increased breast cancer risk. Highly specific examinations, however, may have relatively low sensitivity for breast cancer. Diagnostic CBE, meanwhile, is relatively nonspecific.

Estimating risk of breast cancer in carriers of BRCA1 and BRCA2 mutations: a meta-analytic approach.

Estimates of penetrance (or risk) of breast cancer among BRCA mutation carriers in published studies are heterogeneous, prohibiting direct combined estimates. Estimates of prevalence of BRCA mutations are more homogeneous and could allow combined estimates of prevalence. We propose a combined estimator of penetrance from combined estimates of the prevalence of BRCA mutations in women with and without breast cancer and from the probability of breast cancer by using Bayes' Theorem. The relative risk of having breast cancer with positive family history and the prevalence of positive family history contribute to the combined estimate of penetrance if family history is present. The combined estimate incorporates variation in estimates from different resources. The method is illustrated by using data from Ashkenazi Jewish women unselected for family history and for those with family history. Risks of breast cancer conferred by BRCA1 and BRCA2 mutations are estimated to be 8.39 per cent (6.56, 10.68 per cent) and 2.66 per cent (1.85, 3.82 per cent) by 40 years old, and 47.45 per cent (37.39, 57.72 per cent) and 31.85 per cent (23.72, 41.26 per cent) by 75 years old, respectively. For those with family history, risks of breast cancer conferred by BRCA mutations appear to be higher.

Quality of life after bilateral prophylactic mastectomy.

BACKGROUND: Bilateral prophylactic mastectomy in women with increased breast cancer risk dramatically reduces breast cancer occurrence but little is known about psychosocial outcomes. METHODS: To examine long-term quality of life after bilateral prophylactic mastectomy, we mailed surveys to 195 women who had the procedure from 1979 to 1999 and to a random sample of 117 women at increased breast cancer risk who did not have the procedure. Measures were modeled on or drawn directly from validated instruments designed to assess quality of life, body image, sexuality, breast cancer concerns, depression, health perception, and demographic characteristics. We used logistic regression to examine associations between quality of life and other domains. RESULTS: The response rate was 58%, with 106 women with and 62 women without prophylactic mastectomy returning complete surveys. Among women who underwent bilateral prophylactic mastectomy, 84% were satisfied with their decision to have the procedure; 61% reported high contentment with quality of life compared with an identical 61% of women who did not have the procedure (P = 1.0). Among all subjects, diminished contentment with quality of life was not associated with bilateral prophylactic mastectomy but with dissatisfaction with sex life (adjusted ratio [OR] = 2.5, 95% confidence interval [CI] = 1.0-6.2), possible depression (CES-D > 16, OR = 4.9, CI = 2.0-11.8), and poor or fair general health perception (OR = 8.3, 95% CI = 2.4-29.0). CONCLUSIONS: The majority of women reported satisfaction with bilateral prophylactic mastectomy and experienced psychosocial outcomes similar to women with similarly elevated breast cancer risk who did not undergo prophylactic mastectomy. Bilateral prophylactic mastectomy appears to neither positively nor negatively impact long-term psychosocial outcomes.

Geographic and racial/ethnic differences in HFE mutation frequencies in the Hemochromatosis and Iron Overload Screening (HEIRS) Study.

OBJECTIVE: To assess geographic differences in the frequencies of HFE C282Y and H63D genotypes in six racial/ethnic groups recruited in the Hemochromatosis and Iron Overload Screening (HEIRS) Study. DESIGN: HFE C282Y and H63D genotypes of 97,551 participants, ages > or = 25 years, who reported that they belonged to one of six racial/ethnic groups, were analyzed. HFE genotype frequencies were compared among the racial/ethnic groups and among the HEIRS Study field centers within each racial/ethnic group. RESULTS: The distribution of HFE C282Y and H63D genotypes differed among racial/ethnic groups (P<.0001) and among field centers in Hispanics, Asians, Whites, and Blacks (each P<.05). Genotype frequencies were similar among field centers in Native Americans and Pacific Islanders. Frequencies of C282Y and H63D genotypes were greatest in Whites. The lowest frequencies of C282Y genotypes were observed in Asians; Blacks had the lowest H63D genotype frequencies and the highest frequency of the wild-type genotype. Among racial/ethnic groups, Hispanics had the greatest variation in HFE genotypes across geographic regions. CONCLUSION: HFE C282Y and H63D genotype frequencies vary significantly between racial/ethnic groups and within some racial/ethnic groups across geographic regions.

Mixture models of serum iron measures in population screening for hemochromatosis and iron overload.

Homozygosity for the C282Y mutation of the hemochromatosis gene on chromosome 6p (HFE) is a common genetic trait that increases susceptibility to iron overload. The authors describe and apply methodology developed for the analysis of phenotypic and genotypic data from 46,136 non-Hispanic Caucasians, a subset of the multi-ethnic cohort enrolled in the Hemochromatosis and Iron Overload Screening (HEIRS) Study. For analysis of the distribution of transferrin saturation (TS), mixtures of normal distributions were considered and the expectation-maximization (EM) algorithm was applied for parameter estimation. Maximized log-likelihoods were compared, and significance was assessed by resampling. Sensitivity, specificity, and predictive values from the modeled subpopulations were compared with the actual observed genotypes for C282Y and H63D mutations in the HFE gene. A strong association between HFE genotype and TS subpopulations was found in these data collected from different geographic regions, confirming the external validity of the statistical approach when applied to population-based data. It was concluded that mixture modeling of phenotypic data may provide a clinical guide for screening with gender-specific thresholds to identify potential samples for genetic testing.

Relationships of serum ferritin, transferrin saturation, and HFE mutations and self-reported diabetes in the Hemochromatosis and Iron Overload Screening (HEIRS) study.

OBJECTIVE: We evaluated the associations of self-reported diabetes with serum ferritin concentration, transferrin saturation (TfSat), and HFE C282Y and H63D mutations in six racial/ethnic groups recruited at five field centers in the Hemochromatosis and Iron Overload Screening (HEIRS) study. RESEARCH DESIGN AND METHODS: Analyses were conducted on 97,470 participants. Participants who reported a previous diagnosis of diabetes and/or hemochromatosis or iron overload were compared with participants who did not report a previous diagnosis. RESULTS: The overall prevalence of diabetes was 13.8%; the highest prevalence was in Pacific Islanders (20.1%). Of all participants with diabetes, 2.0% reported that they also had hemochromatosis or iron overload. The mean serum ferritin concentration was significantly greater in women with diabetes in all racial/ethnic groups and in Native-American men with diabetes than in those without diabetes. The mean serum ferritin concentration was significantly lower in Asian men with diabetes than in those without diabetes. Mean TfSat was lower in participants with diabetes from all racial/ethnic groups except Native-American women than in those without diabetes. There was no significant association of diabetes with HFE genotype. The mean serum ferritin concentration was greater (P < 0.0001) in women with diabetes than in those without diabetes for HFE genotypes except C282Y/C282Y and C282Y/H63D. Log serum ferritin concentration was significantly associated with diabetes in a logistic regression analysis after adjusting for age, sex, racial/ethnic group, HFE genotype, and field center. CONCLUSIONS: Serum ferritin concentration is associated with diabetes, even at levels below those typically associated with hemochromatosis or iron overload.