Y chromosome gene copy number and lack of autism phenotype in a male with an isodicentric Y chromosome and absent NLGN4Y expression.

We describe a unique male with a dicentric Y chromosome whose phenotype was compared to that of males with 47,XYY (XYY). The male Y-chromosome aneuploidy XYY is associated with physical, behavioral/cognitive phenotypes, and autism spectrum disorders. We hypothesize that increased risk for these phenotypes is caused by increased copy number/overexpression of Y-encoded genes. Specifically, an extra copy of the neuroligin gene NLGN4Y might elevate the risk of autism in boys with XYY. We present a unique male with the karyotype 46,X,idic(Y)(q11.22), which includes duplication of the Y short arm and proximal long arm and deletion of the distal long arm, evaluated his physical, behavioral/cognitive, and neuroimaging/magnetoencephalography (MEG) phenotypes, and measured blood RNA expression of Y genes. The proband had tall stature and cognitive function within the typical range, without autism features. His blood RNA showed twofold increase in expression of Yp genes versus XY controls, and absent expression of deleted Yq genes, including NLGN4Y. The M100 latencies were similar to findings in typically developing males. In summary, the proband had overexpression of a subset of Yp genes, absent NLGN4Y expression, without ASD findings or XYY-MEG latency findings. These results are consistent with a role for NLGN4Y overexpression in the etiology of behavioral phenotypes associated with XYY. Further investigation of NLGN4Y as an ASD risk gene in XYY is warranted. The genotype and phenotype(s) of this subject may also provide insight into how Y chromosome genes contribute to normal male development and the male predominance in ASD.

Evaluation of the American-English Quality of Life in Short Stature Youth (QoLISSY) questionnaire in the United States.

BACKGROUND: The European Quality of Life in Short Stature Youth (QoLISSY) is a novel condition-specific instrument developed to assess health related quality of life (HrQoL) in children/adolescents with short stature from patient and parent perspectives. Study objective was to linguistically validate and psychometrically test the American-English version of the QoLISSY instrument. METHODS: Upon conversion of the British-English version to American-English, content validity and acceptance of the questionnaire were examined through focus group discussions with cognitive debriefing in 28 children/adolescents with growth hormone deficiency (GHD) or idiopathic short stature (ISS) and their parents. In the subsequent field test with 51 families and a re-test with 25 families the psychometric performance of the American-English version was examined and compared with the original European dataset. RESULTS: Pilot test results supported the suitability of the American-English version. Good internal consistency with Cronbach's Alpha ranging from 0.84 to 0.97 and high test-re-test reliabilities were observed in the field test. The QoLISSY was able to detect significant differences according to the degree of short stature with higher HrQoL for taller children. Correlations with a generic HrQoL tool support the QoLISSY's concurrent validity. The scale's operating characteristics were comparable to the original European data. CONCLUSION: Results support that the QoLISSY American-English version is a psychometrically sound short stature-specific instrument to assess the patient- and parent- perceived impact of short stature. The QoLISSY instrument is fit for use in clinical studies and health services research in the American-English speaking population.

Review of outcomes after cessation of gonadotropin-releasing hormone agonist treatment of girls with precocious puberty.

Although gonadotropin-releasing hormone agonists (GnRHa) have been the standard of care of central precocious puberty (CPP) management for many years, there are still questions about the long-term consequences of treatment. With increased utilization of GnRHa treatment, it is now possible to assess posttreatment outcomes in the immediate posttreatment period and into adulthood. This literature review reports on the long-term effects of GnRHa therapy in girls with CPP after therapy has been discontinued. Published reports confirm the reversibility of hypothalamic-pituitary-ovarian axis suppression in females after cessation of GnRHa therapy, with the majority of patients achieving ovulatory menstrual cycles of normal timing and duration. GnRHa therapy does not appear to induce polycystic ovary syndrome or have long-term negative repercussions on either bone mineral density or body composition. Evidence is currently insufficient to identify agent-specific differences in outcomes, reproductive function, and health of offspring.

Chronotropic incompetence precedes silent pulmonary embolism.

A patient with recurrent pulmonary emboli collected heart rate data during exercise, which provided important premorbid clues to changes in cardiopulmonary exercise tolerance coincident with accrual of thrombus in the central circulation. On both occasions, chronotropic incompetence (CI) preceded the pulmonary emboli events. When patients with programmed exercise goals notice CI, they should seek professional guidance.

Diagnosis of Central Precocious Puberty.

A thorough history and physical examination including Tanner staging and growth assessments can guide differential diagnosis and aid in the evaluation of precocious puberty. Basal luteinizing hormone levels measured using a highly sensitive assay can be helpful in diagnosing central precocious puberty (CPP). Brain MRI is indicated with males diagnosed with CPP and females under the age of 6 with CPP. As more information becomes available regarding the genetic etiologies of CPP, genetic testing may preclude the need for imaging studies and other hormonal testing, especially in familial cases.

Long-Acting Gonadotropin-Releasing Hormone Analogues for Central Precocious Puberty, Including 45-Mg 6-Month Subcutaneous Leuprolide Acetate: Use for Treatment and Treatment Monitoring.

INTRODUCTION: Studies of gonadotropin-releasing hormone analogues (intramuscular [IM] leuprolide acetate [LA] and triptorelin) for treatment monitoring of central precocious puberty (CPP) demonstrate this approach is effective for confirming pubertal hormone suppression. Herein, we provide new data using subcutaneous LA (SC LA), suggesting similar efficacy for treatment monitoring. METHODS: PubMed, Embase, and CINAHL were searched for studies of GnRHa used to monitor treatment of CPP. The titles and the abstracts were reviewed; 5 studies were selected. Additionally, new unpublished data for SC LA from the original phase 3 trial (primary data published by Klein et al.) were evaluated. Serum luteinizing hormone (LH) and leuprolide levels at screening, 1, 4, and 6 h after the first dose SC LA were analyzed and plotted. RESULTS: Data from 162 children (155 girls) were evaluated. SC and IM LA produced overlapping median LH concentration curves and peak LH concentrations after the first dose. For IM LA, subsequent doses yielded suppressed peak LH levels (2.7 IU/L [mean]). For SC LA, subsequent doses also resulted in significant suppressed peak LH levels (0.2 ± 0.02 IU/L) and achieved sex-steroid hormone suppression of >98%. CONCLUSIONS: Compared to IM LA and triptorelin, long-acting SC LA shows similar burst kinetics and rapid LH rise after the first dose, followed by similar suppression of LH and sex steroids after subsequent doses. Since IM LA and triptorelin have demonstrated usefulness that is comparable to that of traditional GnRH stimulation testing for monitoring CPP, we presume that SC LA may be similarly employed.

Evaluation of high resolution gel ß(2)-transferrin for detection of cerebrospinal fluid leak.

BACKGROUND: Cerebrospinal fluid (CSF) leaks are potentially life-threatening conditions that can be diagnosed by detection of ß(2)-transferrin using protein electrophoresis. Another less commonly available test is ß-trace protein quantitation using immunoassay. The objectives of this study were to evaluate a new immunofixation-based ß(2)-transferrin test for detection of CSF leaks and to compare it to an existing agarose gel electrophoresis test and ß-trace protein immunoassay. METHODS: For method comparison, 63 consecutive samples from physician-ordered ß(2)-transferrin tests were analyzed using two different electrophoresis methods, agarose gel fractionation followed by acid-violet staining, and high resolution agarose gel electrophoresis followed by ß(2)-transferrin immunofixation. A subset of samples (16/63) were analyzed for ß-trace protein. Results were compared against patient chart data for the presence of a CSF leak. Additional studies were performed to assess the stability, detection limit, and analytical specificity of the ß(2)-transferrin immunofixation test. RESULTS: The ß(2)-transferrin immunofixation test had a sensitivity of 100 % (40/40) and specificity of 71 % (12/17) for detection of CSF leaks. By comparison, the agarose gel test had a sensitivity of 87 % (35/40) and specificity of 94 % (16/17). ß-trace protein had a sensitivity of 100 % (10/10) and specificity of 86 % (5/6). Serum and saliva could be differentiated from CSF by the ß(2)-transferrin immunofixation test based on their migration patterns. However, whole blood samples appeared positive for ß(2)-transferrin at a threshold of ~ 4 g/L hemoglobin. At a cut-off of 3 mg/L, ß-trace protein was increased in 10/10 cases with documented CSF leak and in 1/6 patients without CSF leak. CONCLUSIONS: Both the new immunofixation test for ß(2)-transferrin and the ß-trace protein were effective at detecting CSF leaks. Users of the ß(2)-transferrin immunofixation test should be cautioned against interpreting samples with blood contamination.

A review of the genetics and epigenetics of central precocious puberty.

Gonadotrophin dependent sexual precocity, commonly referred to as central precocious puberty (CPP), results from a premature reactivation of the hypothalamic-pituitary-gonadal (HPG) axis before the normal age of pubertal onset. CPP is historically described as girls who enter puberty before the age of eight, and boys before the age of nine. Females are more likely to be diagnosed with idiopathic CPP; males diagnosed with CPP have a greater likelihood of a defined etiology. These etiologies may include underlying CNS congenital defects, tumors, trauma, or infections as well as environmental, genetic, and epigenetic factors. Recently, genetic variants and mutations which may cause CPP have been identified at both the level of the hypothalamus and the pituitary. Single nucleotide polymorphisms (SNPs), monogenetic mutations, and modifications of the epigenome have been evaluated in relationship to the onset of puberty; these variants are thought to affect the development, structure and function of GnRH neurons which may lead to either precocious, delayed, or absent pubertal reactivation. This review will describe recent advances in the field of the genetic basis of puberty and provide a clinically relevant approach to better understand these varying etiologies of CPP.

Suboptimal adherence to prescribed daily growth hormone regimen among medicaid beneficiaries in the United States.

OBJECTIVE: The objective of this retrospective cohort study was to describe the adherence and discontinuation patterns of somatropin over 3 years among children with pGHD insured by Medicaid across the United States. METHODS: Eligible children were aged ≥3 and <16 years with Medicaid coverage, diagnosed with pGHD, and had ≥2 new prescriptions for somatropin between 1 July 2014 and 31 December 2018. Four non-exclusive patient cohorts were constructed (≥3, 12, 24, and 36 months of continuous enrollment after initial prescription). Suboptimal adherence was defined as medication possession ratio <0.80, and discontinuation as a gap of >60 days between somatropin fills. Logistic and proportional hazards regression methods were used to estimate odds of suboptimal adherence and time to discontinuation, respectively. RESULTS: In the 12-month cohort (n = 3623), mean age was 10.5 ± 3.2 years, 70.8% were male, 44.4% White, 29.1% Hispanic, 7.1% Black, and 1.7% Asian. At months 12, 24, and 36, the proportion with suboptimal adherence was 40.9, 50.4, 54.4%, respectively, and 49.2% of patients with ≥3 months of follow-up discontinued therapy. At 12 months, lower age and race/ethnicity (Black vs. White referent) had greater odds of suboptimal adherence. Discontinuation was associated with Black (vs. White referent) race and geographic region. CONCLUSIONS: Sociodemographic characteristics may be risk factors for suboptimal adherence and/or discontinuation of prescribed somatropin therapy. Improving GH regimen adherence among this at-risk population, and specifically among subgroups at highest risk, is warranted to improve clinical outcomes.

Gonadotropin-releasing hormone analog therapies for children with central precocious puberty in the United States.

Gonadotropin-releasing hormone agonists (GnRHa's) are the standard treatment for children with central precocious puberty (CPP). We aim to present data on available GnRHa options with an easy-to-review table and discuss factors that influence treatment selection. Five GnRHa's are currently FDA-approved and prescribed in the US and published data suggest similar safety and efficacy profiles over the first year of treatment. One- and 3-month intramuscular (IM) leuprolide acetate (LA) have long-term safety and efficacy data and allow for flexible dosing. Six-month IM triptorelin pamoate offers a longer duration of treatment, but without long-term efficacy and outcome data. Six-month subcutaneous (SQ) LA combines a SQ route of injection and long duration of action but lacks long-term efficacy and outcome data. The 12-month SQ histrelin acetate implant avoids injections and offers the longest duration of action, but requires a minor surgical procedure with local or general anesthesia. Factors in treatment selection include route of administration, needle size, injection volume, duration of action, and cost. The current GnRHa landscape provides options with varying benefits and risks, allowing physicians and caregivers to select the most appropriate therapy based on the specific needs and concerns of the child and the caregiver. Agents have different advantages and disadvantages for use, with no one agent displaying superiority.

Efficacy and Safety of Weekly Somatrogon vs Daily Somatropin in Children With Growth Hormone Deficiency: A Phase 3 Study.

CONTEXT: Somatrogon is a long-acting recombinant human growth hormone (rhGH) in development for once-weekly treatment of children with growth hormone deficiency (GHD). OBJECTIVE: We aimed to compare the efficacy and safety of once-weekly somatrogon with once-daily somatropin in prepubertal children with GHD. METHODS: In this 12-month, open-label, randomized, active-controlled, parallel-group, phase 3 study, participants were randomized 1:1 to receive once-weekly somatrogon (0.66 mg/kg/week) or once-daily somatropin (0.24 mg/kg/week) for 12 months. A total of 228 prepubertal children (boys aged 3-11 years, girls aged 3-10 years) with GHD, impaired height and height velocity (HV), and no prior rhGH treatment were randomized and 224 received ≥1 dose of study treatment (somatrogon: 109; somatropin: 115). The primary endpoint was annualized HV at month 12. RESULTS: HV at month 12 was 10.10 cm/year for somatrogon-treated subjects and 9.78 cm/year for somatropin-treated subjects, with a treatment difference (somatrogon-somatropin) of 0.33 (95% CI: -0.24, 0.89). The lower bound of the 2-sided 95% CI was higher than the prespecified noninferiority margin (-1.8 cm/year), demonstrating noninferiority of once-weekly somatrogon vs daily somatropin. HV at month 6 and change in height standard deviation score at months 6 and 12 were similar between both treatment groups. Both treatments were well tolerated, with a similar percentage of subjects experiencing mild to moderate treatment-emergent adverse events in both groups (somatrogon: 78.9%, somatropin: 79.1%). CONCLUSION: The efficacy of once-weekly somatrogon was noninferior to once-daily somatropin, with similar safety and tolerability profiles. (ClinicalTrials.gov no. NCT02968004).

Clinical characteristics and treatment patterns with histrelin acetate subcutaneous implants vs. leuprolide injections in children with precocious puberty: a real-world study using a US claims database.

OBJECTIVES: Gonadotropin-releasing hormone analogs are the treatment of choice for central precocious puberty (CPP). This study characterizes patients treated with histrelin implant or leuprolide injection. METHODS: A US claims database was used to identify patients aged ≤20 years with ≥1 histrelin or leuprolide claim (index treatment) between April 2010 and November 2017 and continuous enrollment ≥3 months before and ≥12 months after the index treatment date. RESULTS: Overall, 4,217 patients (histrelin, n=1,001; leuprolide, n=3,216) were identified. The percentage of patients with CPP diagnosis was greater in the histrelin (96.5%) vs. leuprolide (68.8%; p<0.0001) cohort. In patients with CPP (histrelin, n=966; leuprolide, n=2,214), mean age at treatment initiation was similar for histrelin (9.0 ± 2.0 years) and leuprolide (9.1 ± 2.3 years), with >50% of patients aged 6-9 years. Mean treatment duration was significantly longer for histrelin (26.7 ± 14.8 months) vs. leuprolide (14.1 ± 12.1 months; p<0.0001), and was longer in younger patient groups. More patients switched from leuprolide to histrelin (12.3%) than vice versa (3.6%; p<0.0001). Median annual total treatment costs were slightly lower for the histrelin cohort ($23,071 [interquartile range, $16,833-$31,050]) than the leuprolide cohort ($27,021 [interquartile range, $18,314-$34,995]; p<0.0001). CONCLUSIONS: Patients with CPP treated with histrelin had a longer duration of treatment, lower rates of index treatment discontinuation, and lower annual treatment costs vs. those treated with leuprolide.

Genetic modifiers of liver disease in cystic fibrosis.

CONTEXT: A subset (approximately 3%-5%) of patients with cystic fibrosis (CF) develops severe liver disease with portal hypertension. OBJECTIVE: To assess whether any of 9 polymorphisms in 5 candidate genes (alpha(1)-antitrypsin or alpha(1)-antiprotease [SERPINA1], angiotensin-converting enzyme [ACE], glutathione S-transferase [GSTP1], mannose-binding lectin 2 [MBL2], and transforming growth factor beta1 [TGFB1]) are associated with severe liver disease in patients with CF. DESIGN, SETTING, AND PARTICIPANTS: Two-stage case-control study enrolling patients with CF and severe liver disease with portal hypertension (CFLD) from 63 CF centers in the United States as well as 32 in Canada and 18 outside of North America, with the University of North Carolina at Chapel Hill as the coordinating site. In the initial study, 124 patients with CFLD (enrolled January 1999-December 2004) and 843 control patients without CFLD were studied by genotyping 9 polymorphisms in 5 genes previously studied as modifiers of liver disease in CF. In the second stage, the SERPINA1 Z allele and TGFB1 codon 10 genotype were tested in an additional 136 patients with CFLD (enrolled January 2005-February 2007) and 1088 with no CFLD. MAIN OUTCOME MEASURES: Differences in distribution of genotypes in patients with CFLD vs patients without CFLD. RESULTS: The initial study showed CFLD to be associated with the SERPINA1 Z allele (odds ratio [OR], 4.72; 95% confidence interval [CI], 2.31-9.61; P = 3.3 x 10(-6)) and with TGFB1 codon 10 CC genotype (OR, 1.53; 95% CI, 1.16-2.03; P = 2.8 x 10(-3)). In the replication study, CFLD was associated with the SERPINA1 Z allele (OR, 3.42; 95% CI, 1.54-7.59; P = 1.4 x 10(-3)) but not with TGFB1 codon 10. A combined analysis of the initial and replication studies by logistic regression showed CFLD to be associated with SERPINA1 Z allele (OR, 5.04; 95% CI, 2.88-8.83; P = 1.5 x 10(-8)). CONCLUSIONS: The SERPINA1 Z allele is a risk factor for liver disease in CF. Patients who carry the Z allele are at greater risk (OR, approximately 5) of developing severe liver disease with portal hypertension.

Consensus characterization of 16 FMR1 reference materials: a consortium study.

Fragile X syndrome, which is caused by expansion of a (CGG)(n) repeat in the FMR1 gene, occurs in approximately 1:3500 males and causes mental retardation/behavioral problems. Smaller (CGG)(n) repeat expansions in FMR1, premutations, are associated with premature ovarian failure and fragile X-associated tremor/ataxia syndrome. An FMR1-sizing assay is technically challenging because of high GC content of the (CGG)(n) repeat, the size limitations of conventional PCR, and a lack of reference materials available for test development/validation and routine quality control. The Centers for Disease Control and Prevention and the Association for Molecular Pathology, together with the genetic testing community, have addressed the need for characterized fragile X mutation reference materials by developing characterized DNA samples from 16 cell lines with repeat lengths representing important phenotypic classes and diagnostic cutoffs. The alleles in these materials were characterized by consensus analysis in nine clinical laboratories. The information generated from this study is available on the Centers for Disease Control and Prevention and Coriell Cell Repositories websites. DNA purified from these cell lines is available to the genetics community through the Coriell Cell Repositories. The public availability of these reference materials should help support accurate clinical fragile X syndrome testing.

Veganism as a cause of iodine deficient hypothyroidism.

BACKGROUND: Iodine deficiency is the most common cause of acquired hypothyroidism worldwide. Although uncommon in the Western world, the incidence of iodine deficiency may be rising due to the increased use of restrictive diets. CASE PRESENTATION: We present a 23-month-old boy diagnosed with iodine deficiency hypothyroidism, induced by a vegan diet. CONCLUSIONS: This case highlights the risk for iodine deficiency in children on a vegan diet after discontinuation of breast/formula feeding that could lead to acquired hypothyroidism.

Efficacy and safety of histrelin subdermal implant in children with central precocious puberty: a multicenter trial.

CONTEXT: GnRH analog (GnRHa) therapy for central precocious puberty (CPP) typically involves im injections. The histrelin implant is a new treatment that provides a continuous slow release of the GnRHa histrelin. OBJECTIVE: The objective of the study was to investigate the safety and efficacy of the subdermal histrelin implant for the treatment of CPP in treatment naive and previously treated children. DESIGN: This was a phase III, open-label, prospective study of 1-yr duration. SETTING: The study was conducted at nine U.S. medical centers. PATIENTS: Girls ages 2-8 yr (naive) or 2-10 yr (previously treated) and boys 2-9 yr (naive) or 2-11 yr (previously treated) with clinical evidence of CPP and a pretreatment pubertal response to leuprolide stimulation were eligible. INTERVENTION: A 50-mg histrelin implant was inserted sc in the inner upper arm. MAIN OUTCOME MEASURES: Peak LH after GnRHa stimulation testing and estradiol (girls) and testosterone (boys) were the main outcome measures. RESULTS: Thirty-six subjects (20 naive) were enrolled. By 1 month, peak LH fell from 28.2 +/- 19.97 (naive) to 0.8 +/- 0.39 mIU/ml (P < 0.0001) and from 2.1 +/- 2.15 (previously treated) to 0.5 +/- 0.32 mIU/ml (P < 0.0056). Estradiol suppressed from 24.5 +/- 22.27 (naive) to 5.9 +/- 2.37 pg/ml (P = 0.0016) and remained suppressed in previously treated subjects, as did testosterone. Suppression was maintained throughout the study. No significant adverse events occurred. CONCLUSIONS: The subdermal histrelin implant achieves and maintains excellent suppression of peak LH and sex steroid levels for 1 yr in children with CPP. The treatment is well tolerated. Long-term studies are needed to confirm these results.

Acceptance of fragile X premutation genetic screening in women with ovarian dysfunction.

OBJECTIVE: The purpose of this study was to assess patient perception of fragile X premutation genetic testing (FRAX). STUDY DESIGN: This was a cross-sectional survey of women with elevated follicle stimulating hormone levels with (premature ovarian failure or early menopause [POF/EM], n = 20) or without (diminished ovarian reserve [DOR], n = 20) amenorrhea. Seventy-five percent participated. RESULTS: Seventy-five percent of the DOR group and 43% of the POF/EM group desired FRAX testing. Eighty-three percent wanted to assist the scientific knowledge of FRAX, even if they did not want to know their own results. POF/EM women were more concerned than DOR women about paying out-of-pocket (P = .001) and maintaining confidentiality insurance-wise (P = .07). Primary motivations for women who wanted testing were the desire to know if they have FRAX, and wanting to determine if FRAX is the cause of their ovarian dysfunction. The primary decision factor for those declining testing was unwillingness to pay out-of-pocket (75%). CONCLUSION: Women with ovarian dysfunction are interested in FRAX testing. Cost, confidentiality, and the implications for relatives are their key concerns.

Molecular diagnostics: a historical perspective.

The rapid growth in molecular diagnostic testing, which has averaged between 10% and 20% per year for the past 5 years, is largely attributable to both breakthroughs in our basic understanding (i.e., the Human Genome Project) and in applied technology. In the past decade, molecular applications have moved from labor-intensive and manual to rapid and automated due to improvements in sample extraction, target amplification, and sensitive and specific detection schema. This review describes some of the more significant technological milestones of the past 10 years and, when tied to basic and applied research, how these have led to important clinical applications. The next decade promises even more exciting technologies and applications for the field of molecular laboratory medicine.

Association between hemochromatosis (HFE) gene mutation carrier status and the risk of colon cancer.

BACKGROUND: Iron is a pro-oxidant that may promote carcinogenesis. Mutations in the hemochromatosis (HFE) gene are associated with increased total body iron stores in some individuals. We assessed the risk of colon cancer among individuals with and without HFE gene mutations. METHODS: We performed a population-based, case-control study in North Carolina. Case patients with colon cancer and control subjects provided information on multiple environmental exposures, including total iron intake and nonsteroidal anti-inflammatory drug (NSAID) use. They also provided a venous blood sample, from which DNA was extracted, amplified, and subjected to diagnostic restriction enzyme mapping to detect two major HFE gene mutations, C282Y and H63D. Data were analyzed with Fisher's exact test and logistic regression. All statistical tests were two-sided. RESULTS: Thirteen hundred and eight subjects participated (475 case patients, 833 control subjects). The allele frequencies of the H63D and C282Y mutations were greater among case patients (0.11 and 0.046, respectively) than among control subjects (0.09 and 0.044, respectively; P =.14 and P =.85, respectively). When we controlled for age, race, sex, red meat consumption, NSAID use, and total iron intake, subjects with any HFE gene mutation were more likely to have colon cancer than subjects with no HFE gene mutations (adjusted odds ratio [OR] = 1.40, 95% confidence interval [CI] = 1.07 to 1.87). The magnitude of the effect was similar for both the H63D (adjusted OR = 1.44, 95% CI = 1.04 to 1.98) and C282Y mutations (adjusted OR = 1.39, 95% CI = 0.88 to 2.19). The risk of colon cancer associated with an HFE gene mutation was similar for those who did and did not have a family history of colon cancer. Among those with HFE mutations, cancer risk increased with increasing age and total iron intake. CONCLUSIONS: HFE gene mutations are associated with an increased risk of colon cancer. Cancer risk is greatest in mutation carriers who are older or consume high quantities of iron.