Toward Equitable Precision Oncology: Monitoring Racial and Ethnic Inclusion in Genomics and Clinical Trials.

PURPOSE: Ethnic diversity in cancer research is crucial as race/ethnicity influences cancer incidence, survival, drug response, molecular pathways, and epigenetic phenomena. In 2018, we began a project to examine racial/ethnic diversity in cancer research, with a commitment to review these disparities every 4 years. This report is our second assessment, detailing the present state of racial/ethnic diversity in cancer genomics and clinical trials. METHODS: To study racial/ethnic inclusion in cancer genomics, we extracted ethnic records from all data sets available at cBioPortal (n = 125,128 patients) and cancer-related genome-wide association studies (n = 28,011,282 patients) between 2018 and 2022. Concerning clinical trials, we selected studies related to breast cancer (n = 125,518 patients, 181 studies), lung cancer (n = 34,329 patients, 119 studies), and colorectal cancer (n = 40,808 patients, 105 studies). RESULTS: In cancer genomics (N = 28,136,410), 3% of individuals lack racial/ethnic registries; tumor samples were collected predominantly from White patients (89.14%), followed by Asian (7%), African American (0.55%), and Hispanic (0.21%) patients and other populations (0.1%). In clinical trials (N = 200,655), data on race/ethnicity are missing for 60.14% of the participants; for individuals whose race/ethnicity was recorded, most were characterized as White (28.33%), followed by Asian (7.64%), African (1.79), other ethnicities (1.37), and Hispanic (0.73). Racial/ethnic representation significantly deviates from global ethnic proportions (P ≤ .001) across all data sets, with White patients outnumbering other ethnic groups by a factor of approximately 4-6. CONCLUSION: Our second update on racial/ethnic representation in cancer research highlights the persistent overrepresentation of White populations in cancer genomics and a notable absence of racial/ethnic information across clinical trials. To ensure more equitable and effective precision oncology, future efforts should address the reasons behind the insufficient representation of ethnically diverse populations in cancer research.

[Progress in Gene Polymorphisms Associated With Osteoporosis Susceptibility in Zhuang Ethnic Group in Guangxi].

The purpose of this paper is to systematically summarize the gene polymorphisms associated with osteoporosis(OP)susceptibility in Zhuang ethnic group in Guangxi.These genes mainly encode vitamin D receptor,estrogen receptor,calcitonin receptor,and adiponectin.The genotype and allele distribution frequency were compared between Zhuang ethnic group and other ethnic groups,which can clarify the existing genes and the potential gene polymorphism associated with OP in Zhuang ethnic group.The findings provide a representative solution for the subsequent research on the genes associated with OP susceptibility in ethnic minorities.

Recruiting refugees and migrants as potential hematopoietic stem cell donors to serve patients of comparable ethnicities with rare human leucocyte antigen patterns - The BluStar.NRW project in North Western Germany.

Currently, approximately 19 million people with a migration background live in Germany. The majority of those descend from regions where the population has a genetically different distribution of HLA antigens when compared to the HLA frequencies usually found in North Western Europe. In case of severe haematological disorders of these individuals, allogeneic stem cell transplantation may be the treatment of choice. However, finding appropriate histocompatible hematopoietic stem cell donors continues to be a major challenge. If no matching sibling donors are available, there are only few suitable donors with a similar genetic background available in international blood stem cell donor registries. The "BluStar.NRW" project aimed to recruit new blood and hematopoietic stem cell donors with a migration background and to noticeably increase the number of suitable donors for patients within this group. Since December 2017, a total number of 9100 blood and stem cell donors with a migration background were recruited and typed for this project. HLA typing for HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1 was performed by Next Generation Sequencing. We assessed the proportion of rare alleles according to HLA frequency tables, as defined by a frequency of <1:1000. The rare HLA allele frequencies according to HLA frequency tables of the BluStar.NRW cohort were compared with a matched control donor cohort: Rare HLA-A, -B, -C, -DRB1 and -DQB1 alleles occurred three times more frequent than in the control group, but rare HLA-DPB1 alleles occurred more frequently in the control cohort. This difference was highly significant for all HLA alleles (p < 0.0001 for HLA-A, -B, -C, -DRB1, -DPB1; p = 0.0002 for HLA-DQB1). In addition, the distribution of rare alleles differed between the two groups. To date, 29 work-ups were initiated, 12 PBSC, one BM and three DLI were collected so far out of the BluStar.NRW cohort. The apheresis probability is twofold higher (0.18% vs. 0.07%) compared to the control group which clearly shows a serious medical need. However, 13 work-ups were cancelled in the BluStar.NRW donor cohort which represents an almost twice as higher cancellation rate (45% vs. 25%). This single registry analysis with a large sample cohort clearly indicates that hematopoietic stem cell donors with a migration background represent an adequate donor pool to serve patients of comparable ethnicity.

Reduction in Breast Cancer Death With Adjuvant Chemotherapy Among US Women According to Race, Ethnicity, and the 21-Gene Recurrence Score.

BACKGROUND: We previously showed the 21-gene breast recurrence score (RS) has lower prognostic accuracy for non-Hispanic Black (NHB) compared with non-Hispanic White (NHW) women with estrogen receptor (ER)-positive/HER2-negative breast cancer. The purpose of this study was to determine the clinical validity of the RS for predicting chemotherapy benefit as recommended in the current NCCN Guidelines for Breast Cancer among women from diverse racial/ethnic groups. METHODS: Using the SEER Oncotype database, we estimated propensity score-weighted hazard ratios (HRs) and 95% confidence intervals for breast cancer death with chemotherapy for women with ER-positive/HER2-negative, AJCC stages I-II, axillary node-negative, invasive breast cancer according to race/ethnicity. RESULTS: We included 6,033 (8.2%) Asian/Pacific Islander (API), 5,697 (7.8%) NHB, 6,688 (9.1%) Hispanic, and 54,945 (74.9%) NHW women. Breast cancer death was reduced with chemotherapy for NHB (HR, 0.48, 95% CI, 0.28-0.81), Hispanic (HR, 0.48; 95% CI, 0.25-0.94), and NHW (HR, 0.80; 95% CI, 0.65-0.99) women with an RS of 26 to 100. There was a nonsignificant reduction for API women (HR, 0.59; 95% CI, 0.28-1.24). For women with an RS of 11 to 25, there was no reduction in death for any racial/ethnic group. Among women aged ≤50 years, the reduction in breast cancer death with chemotherapy differed according to race (NHB: HR, 0.37 [95% CI, 0.20-0.67]; NHW: HR, 0.56 [95% CI, 0.44-0.74]; Pinteraction for chemotherapy * race <.0499). An exploratory subgroup analysis found that young NHB women may benefit from chemotherapy at a lower RS cutoff than other women. CONCLUSIONS: The RS was clinically validated as a predictive biomarker for NHB, Hispanic, and NHW women with ER-positive, axillary node-negative breast cancer, but it may underestimate the benefit of chemotherapy for young NHB women. If this finding is confirmed, the RS cutoff for recommending adjuvant chemotherapy for young NHB women with ER-positive, axillary node-negative breast cancer may need to be lower than for other women.

Genomic ancestry in kidney cancer: Correlations with clinical and molecular features.

INTRODUCTION: Genetic ancestry (GA) refers to population hereditary patterns that contribute to phenotypic differences seen among race/ethnicity groups, and differences among GA groups may highlight unique biological determinants that add to our understanding of health care disparities. METHODS: A retrospective review of patients with renal cell carcinoma (RCC) was performed and correlated GA with clinicopathologic, somatic, and germline molecular data. All patients underwent next-generation sequencing of normal and tumor DNA using Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets, and contribution of African (AFR), East Asian (EAS), European (EUR), Native American, and South Asian (SAS) ancestry was inferred through supervised ADMIXTURE. Molecular data was compared across GA groups by Fisher exact test and Kruskal-Wallis test. RESULTS: In 953 patients with RCC, the GA distribution was: EUR (78%), AFR (4.9%), EAS (2.5%), SAS (2%), Native American (0.2%), and Admixed (12.2%). GA distribution varied by tumor histology and international metastatic RCC database consortium disease risk status (intermediate-poor: EUR 58%, AFR 88%, EAS 74%, and SAS 73%). Pathogenic/likely pathogenic germline variants in cancer-predisposition genes varied (16% EUR, 23% AFR, 8% EAS, and 0% SAS), and most occurred in CHEK2 in EUR (3.1%) and FH in AFR (15.4%). In patients with clear cell RCC, somatic alteration incidence varied with significant enrichment in BAP1 alterations (EUR 17%, AFR 50%, SAS 29%; p = .01). Comparing AFR and EUR groups within The Cancer Genome Atlas, significant differences were identified in angiogenesis and inflammatory pathways. CONCLUSION: Differences in clinical and molecular data by GA highlight population-specific variations in patients with RCC. Exploration of both genetic and nongenetic variables remains critical to optimize efforts to overcome health-related disparities.

Racial Disparities in Accessing Care along the Continuum of Cancer Genetic Service Delivery.

BACKGROUND: Public health calls to ensure equity in genomics and precision medicine necessitate a closer examination of how these efforts might differentially affect access to genetic services across demographic subgroups. This study set out to examine racial/ethnic disparities along the cancer genetic service delivery continuum. METHODS: Retrospective data are drawn from 15 clinical sites across 6 U.S. States. Individuals who screened at-risk for hereditary cancer were: (i) referred/scheduled to see a genetic counselor (referral workflow), or (ii) offered genetic testing at the point-of-care (POC testing workflow). Logistic regression analyses evaluated the associations between race/ethnicity and several outcomes including appointment scheduling, genetic counseling, and genetic testing, controlling for demographics, clinical factors, and county-level covariates. RESULTS: A total of 14,527 patients were identified at-risk. Genetic testing uptake was significantly higher at POC sites than referral sites (34% POC vs. 11% referral, P < 0.001). Race/ethnicity was significantly associated with testing uptake among all sites, with non-Hispanic Blacks having lower odds of testing compared with non-Hispanic Whites [aOR = 0.84; 95% confidence interval (CI), 0.71-1.00; P = 0.049]. Moreover, this disparity was observed at referral sites, but not POC sites. Among patients scheduled, non-Hispanic Blacks had lower odds of counseling (aOR = 0.28; 95% CI, 0.17-0.47; P < 0.001). CONCLUSIONS: Findings suggest that factors influencing genetic counseling show rates may be driving disparities in genetic testing. IMPACT: Strategies to reduce barriers to seeing a genetic counselor, including modifications to clinical workflow, may help mitigate racial/ethnic disparities in genetic testing.

Imputation of race and ethnicity categories using genetic ancestry from real-world genomic testing data.

The incompleteness of race and ethnicity information in real-world data (RWD) hampers its utility in promoting healthcare equity. This study introduces two methods-one heuristic and the other machine learning-based-to impute race and ethnicity from genetic ancestry using tumor profiling data. Analyzing de-identified data from over 100,000 cancer patients sequenced with the Tempus xT panel, we demonstrate that both methods outperform existing geolocation and surname-based methods, with the machine learning approach achieving high recall (range: 0.859-0.993) and precision (range: 0.932-0.981) across four mutually exclusive race and ethnicity categories. This work presents a novel pathway to enhance RWD utility in studying racial disparities in healthcare.

Combining Asian and European genome-wide association studies of colorectal cancer improves risk prediction across racial and ethnic populations.

Polygenic risk scores (PRS) have great potential to guide precision colorectal cancer (CRC) prevention by identifying those at higher risk to undertake targeted screening. However, current PRS using European ancestry data have sub-optimal performance in non-European ancestry populations, limiting their utility among these populations. Towards addressing this deficiency, we expand PRS development for CRC by incorporating Asian ancestry data (21,731 cases; 47,444 controls) into European ancestry training datasets (78,473 cases; 107,143 controls). The AUC estimates (95% CI) of PRS are 0.63(0.62-0.64), 0.59(0.57-0.61), 0.62(0.60-0.63), and 0.65(0.63-0.66) in independent datasets including 1681-3651 cases and 8696-115,105 controls of Asian, Black/African American, Latinx/Hispanic, and non-Hispanic White, respectively. They are significantly better than the European-centric PRS in all four major US racial and ethnic groups (p-values < 0.05). Further inclusion of non-European ancestry populations, especially Black/African American and Latinx/Hispanic, is needed to improve the risk prediction and enhance equity in applying PRS in clinical practice.

Racial and Ethnic Disparities in Genomic Healthcare Utilization, Patient Activation, and Intrafamilial Communication of Risk among Females Tested for BRCA Variants: A Mixed Methods Study.

This study aimed to gain a deeper understanding of genomic healthcare utilization, patient activation, and intrafamilial risk communication among racially and ethnically diverse individuals tested for BRCA variants. We employed an explanatory, sequential, mixed-methods study guided by the Theory of Planned Behavior. Participants completed an online survey, including sociodemographic, medical history, and several validated instruments. A subset of participants participated in in-depth, semi-structured interviews. A total of 242 women were included in the quantitative analyses. The majority of survey participants identified as non-Hispanic white (NHW) (n = 197, 81.4%) while 45/242 (18.5%) identified as black, Indigenous, and people of color (BIPOC). The NHW participants were more likely to communicate genetic test results with healthcare providers, family, and friends than BIPOC participants (p < 0.05). BIPOC participants had lower satisfaction with testing decisions and significantly higher ratings of personal discrimination, fatalism, resilience, uncertainty, and lower patient activation scores (p < 0.05). Participants with higher education, greater satisfaction with testing decisions, and lower resilience are more likely to communicate BRCA test results with family members through the mediating effect of patient activation. Bridging disparities to ensure that genomic healthcare benefits all people may demand theory-driven, multi-level interventions targeting the individual, interpersonal, and healthcare system levels.

Characterizing the polygenic architecture of complex traits in populations of East Asian and European descent.

To investigate the polygenicity of complex traits in populations of East Asian (EAS) and European (EUR) descents, we leveraged genome-wide data from Biobank Japan, UK Biobank, and FinnGen cohorts. Specifically, we analyzed up to 215 outcomes related to 18 health domains, assessing their polygenic architecture via descriptive statistics, such as the proportion of susceptibility SNPs per trait (πc). While we did not observe EAS-EUR differences in the overall distribution of polygenicity parameters across the phenotypes investigated, there were ancestry-specific patterns in the polygenicity differences between health domains. In EAS, pairwise comparisons across health domains showed enrichment for πc differences related to hematological and metabolic traits (hematological fold-enrichment = 4.45, p = 2.15 × 10-7; metabolic fold-enrichment = 4.05, p = 4.01 × 10-6). For both categories, the proportion of susceptibility SNPs was lower than that observed for several other health domains (EAS-hematological median πc = 0.15%, EAS-metabolic median πc = 0.18%) with the strongest πc difference with respect to respiratory traits (EAS-respiratory median πc = 0.50%; hematological-p = 2.26 × 10-3; metabolic-p = 3.48 × 10-3). In EUR, pairwise comparisons showed multiple πc differences related to the endocrine category (fold-enrichment = 5.83, p = 4.76 × 10-6), where these traits showed a low proportion of susceptibility SNPs (EUR-endocrine median πc = 0.01%) with the strongest difference with respect to psychiatric phenotypes (EUR-psychiatric median πc = 0.50%; p = 1.19 × 10-4). Simulating sample sizes of 1,000,000 and 5,000,000 individuals, we also showed that ancestry-specific polygenicity patterns translate into differences across health domains in the genetic variance explained by susceptibility SNPs projected to be genome-wide significant (e.g., EAS hematological-neoplasm p = 2.18 × 10-4; EUR endocrine-gastrointestinal p = 6.80 × 10-4). These findings highlight that traits related to the same health domains may present ancestry-specific variability in their polygenicity.

Genetic Ancestry of 1127 Brazilian Breast Cancer Patients and Its Correlation With Molecular Subtype and Geographic Region.

PURPOSE: Breast cancer molecular subtypes show significant differences in different ethnic groups in the United States, but no study has evaluated genetic ancestry in breast cancer in Brazilian women. METHODS: Breast cancer patients from distinct parts of Brazil were evaluated. Molecular subtypes were determined by immunohistochemistry. Genetic ancestry was evaluated using a panel of 46 AIMs (ancestry informative markers), which classified genetic ancestry as European, African, Asian, and Amerindian. PCR products were subjected to capillary electrophoresis and analyzed using GeneMapper 4.0 software. Ancestry was evaluated with Structure v.2.3.3 software. Ancestry was tested for correlations with geographic region and molecular subtype. The chi-square test and ANOVA with Bonferroni adjustment were applied. RESULTS: Genetic ancestry and clinical data were evaluated in 1127 patients. Higher rates of self-reported white ethnicity, European ancestry, and HER-2- luminal tumors were identified in the South region, which may influence age at diagnosis and result in a higher rate of early tumors. Conversely, higher rates of African ancestry in the North and Northeast regions, self-reported nonwhite ethnicity, HER-2+ tumors, and triple-negative tumors were noted. Triple-negative and HER-2+ tumors were associated with higher advanced and metastatic disease rates at diagnosis, with triple-negative tumors being more frequent in young women. CONCLUSION: Differences in genetic ancestry, self-reported ethnicity, and molecular subtype were found between Brazilian demographic regions. Knowledge of these features may contribute to a better understanding of age at diagnosis and the molecular distribution of breast cancer in Brazil.

Residential Locale Is Associated with Disparities in Genetic Testing-Related Outcomes Among BRCA1/2-Positive Women.

BACKGROUND: While research on hereditary genetic testing for BRCA1/2 mutations continues to emerge, there remain unanswered questions regarding access to testing and cancer-related care. Our study determined the associations between race/ethnicity, residential locale, and genetic testing provider and related outcomes among US women with BRCA1/2 genetic mutations. METHODS: One hundred ninety-three BRCA1/2-positive women from vulnerable health backgrounds were recruited via private national Facebook BRCA1/2-oriented support groups and completed an online survey. Adjusted odds ratios (aOR) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression for the associations between race/ethnicity, residential locale, and genetic testing-related outcomes. RESULTS: Women ranged in age (18-75, M = 39.5, SD = 10.7), and most were non-Hispanic white (66.3%) and lived in a suburban locale (54.9%). Women living in suburban areas were significantly less likely (aOR, .369, 95% CI, .177-.771) to receive behavioral referrals after genetic testing compared to those living in an urban locale. Women living in rural areas and suburban areas were 4.72 times more likely (95% CI, 1.48-15.1, p = .009) and 2.61 times more likely (95% CI, 1.05-6.48, p = .038), respectively, to receive genetic testing from a primary care provider versus private genetic testing office/hospital compared to women in urban locales. Associations between race/ethnicity and genetic testing outcomes were not statistically significant. Residential locale did not predict the odds of undergoing surgery for risk reduction or surveillance for early detection. CONCLUSION: Our study identifies disparities in genetic testing resources among women living in suburban and rural areas. These findings can be used to inform future care, research, and community resources that may impact services relating to genetic testing within these locales.

Racial and ethnic variation in BRCA1 and BRCA2 genetic test results among individuals referred for genetic counseling at a large urban comprehensive cancer center.

PURPOSE: The prevalence of pathogenic variants in BRCA1 and BRCA2 in populations other than Ashkenazi Jewish (AJ) is not well defined. We describe the racial and ethnic-specific prevalence of BRCA1/2 pathogenic variants and variants of uncertain significance (VUS) among individuals referred for genetic testing in a large urban comprehensive cancer center over a 20-year period. METHODS: The population included 3,537 unrelated individuals who underwent genetic testing from January 1999 to October 2019 at the Karmanos Cancer Institute. We estimated the prevalence of pathogenic variants and VUS and evaluated associations with race and ethnicity for African American (AA), Arab, AJ and Hispanic individuals compared to Non-Hispanic Whites (NHW). We used multivariable models to adjust for other predictors of pathogenic variants. We also reported the most common pathogenic variants by racial and ethnic group. RESULTS: The racial and ethnic breakdown of our population was: NHW (68.9%), AA (20.3%), AJ (2.5%), Arab (2.2%), Hispanic (1.0%), Asian Pacific Islander, Native American/Alaskan Native (4.7%), and < 1% unknown. The overall prevalence of pathogenic variants in BRCA1/2 was 8.9% and the prevalence of VUS was 5.6%. Compared to NHW, there were no racial or ethnic differences in the rate of pathogenic variants. However, AA individuals were more likely to have VUS in BRCA1 (adjusted OR 2.43, 95% CI 1.38-4.28) and AJ were more likely to have VUS in BRCA2 (adjusted OR 3.50, 95% CI 1.61-6.58). CONCLUSION: These results suggest the continued need for genetic testing and variant reclassification for individuals of all racial and ethnic groups.

Awareness and use of genetic testing: An analysis of the Health Information National Trends Survey 2020.

PURPOSE: Genetic testing is a tool used in a variety of settings for medical and nonhealth related purposes. The goal of this analysis was to better understand the awareness and use of genetic testing in the United States. METHODS: Data from the 2020 Health Information National Trends Survey 5 cycle 4 were used to assess the awareness and use of genetic testing by demographic characteristics, personal cancer history, and family cancer history. RESULTS: Overall, 75% of participants were aware of genetic testing and 19% of participants had genetic testing. Ancestry testing was the most common type of testing that the participants were aware of and had received. Non-Hispanic Asian, Non-Hispanic Black, and Hispanic respondents and participants with incomes less than $20,000 were less likely to be aware of and have received any type of genetic testing than the Non-Hispanic White participants and participants with higher income, respectively. Participants with a family history of cancer were more likely to be aware of cancer genetic testing than those without, and participants with a personal history of cancer were more likely to have had cancer genetic testing. CONCLUSION: It appears awareness of genetic testing is increasing in the United States, and differences in awareness persist by race/ethnicity and income.

Worldwide Systematic Review of GSTM1 and GSTT1 Null Genotypes by Continent, Ethnicity, and Therapeutic Area.

Glutathione S-transferase Mu 1 (GSTM1) and glutathione S-transferase theta 1 (GSTT1) enzymes are glutathione-S-transferases with broad significance for susceptibility or resistance to multifactorial human diseases, as well as detoxification of environmental chemicals and drugs. Moreover, some individuals may have a complete deletion of GSTM1 and GSTT1 genes, which can contribute to patient-to-patient variability in drug safety and efficacy. GSTM1 and GSTT1 gene deletion frequencies can vary according to ethnicity and continental origin of the studied population with implications for achieving the goal of precision/personalized medicine in clinical practice. We report here a worldwide systematic review of the null genotypes in these two clinically important genes by continents, ethnicities, and therapeutic areas (TAs). Searches were performed in the PubMed database covering the period from 1992 to 2020. Out of the 1925 articles included, most studies analyzed European individuals, corroborating the literature failure for not adequately considering the non-European ethnicities. The frequency of GSTM1 and GSTT1 null genotypes was higher in patients than in healthy volunteers. Conversely, in East Asians, higher frequencies of the null genotypes were observed in healthy volunteers than patients. Oncology was the most intensively studied TA (57% of the articles) in relation to GSTM1 and GSTT1. In all, these results demonstrate that there is an important gap in the literature in terms of failure to consider a broader range of populations, as well as diseases wherein GSTM1 and GSTT1 variations have clinical and biological implications. To achieve precision/personalized medicine on a global/worldwide scale, with equity and inclusiveness, this knowledge/research gap ought to be remedied in studies of GSTM1 and GSTT1 null genotypes. To the best of our knowledge, this is the largest systematic review conducted to date addressing the GSTM1 and GSTT1 null genotypes worldwide. The analyses from the 1925 articles highlighted the current knowledge gaps in different TAs, ethnicities, and populations. Filling these gaps is of importance, given the role these genes play in relation to the metabolism of substances to which we have frequent contact with, the associations observed between their deletion and diseases such as cancer, in addition to the interethnic differences observed for the deletion frequencies of these genes.

Androgen Receptor Gene CAG Repeat Length Varies and Affects Semen Quality in an Ethnic-Specific Fashion in Young Men from Russia.

Male infertility is a multi-factorial and multi-genetic disorder, and the prevalence of male infertility in the world is estimated at 5-35%. The search for the causes of male infertility allowed for identifying a number of genetic factors including a single X-linked gene of the androgen receptor (AR), and some of its alleles are assumed to negatively affect male fertility. Our aim was (1) to study the variability of the length of CAG repeats of the AR gene and possible associations in the AR CAG genetic variants with semen quality and reproductive hormone levels in a population-based cohort of men and (2) to estimate distributions of AR CAG repeat alleles and associations with semen parameters in different ethnic subgroups. The cohort of 1324 young male volunteers of different ethnicities (median age 23.0 years) was recruited from the general population of five cities of the Russian Federation, regardless of their fertility status. Semen quality (sperm concentration, motility and morphology), reproductive hormone levels (testosterone, estradiol, LH, FSH and inhibin B) and trinucleotide (CAG) n repeat polymorphism in exon 1 of the AR gene were evaluated. The semen samples were analyzed according to the WHO laboratory manual (WHO, 2010), serum hormones were measured by enzyme immunoassay, and the AR CAG repeat length was analyzed by direct sequencing of leukocyte DNA. The median AR CAG repeat length in men of our multi-ethnic population was 23 (range 6-39). In the entire study population, a significant difference (p ≤ 0.05) was found in the frequency distribution and the mean values for the CAG repeat length between the groups with normal (23.2 ± 3.3) and impaired semen quality (23.9 ± 3.2). Additionally, we demonstrated that the total sperm count, sperm concentration, progressive motility and normal morphology were lower in the category of long CAG repeats (CAG ≥ 25) compared with those in the category of short CAG repeats (CAG ≤ 19); however, hormonal parameters did not differ between the long and short CAG categories, with the exception of estradiol. Significant differences were observed in the AR CAG repeat length between the most common ethnic cohorts of Slavs (Caucasians), Buryats (Asians), and Yakuts (Asians). The Buryats and Yakuts had a higher number of CAG repeats than the Slavs (medians: Slavs-23; Buryats-24; Yakuts-25). The range of alleles differed among ethnicities, with the Slavs having the largest range (7-36 repeats, 24 alleles total), the Yakuts having the smallest range (18-32 repeats, 14 alleles total) and the Buryats having the middle range (11-39 repeats, 20 alleles total). The longer CAG repeats were associated with an impaired semen quality within the Slavic (CAG ≥ 25) and Buryat (CAG ≥ 28) groups, but this effect was not found in Yakuts. Hormonal parameters did not differ between the three CAG repeat categories in men of all ethnic groups. This is the largest Russian study of the distribution of AR CAG repeats and the search for association between length of AR CAG repeat tract and impaired spermatogenesis in men from the general population. Our results confirmed the association of longer CAG repeats with a risk of impaired semen quality, but this association can be modified by ethnic origin. Identification of the number of AR CAG repeats can be an effective tool to assess the risk of male subfertility and the control of androgen hormone therapy of reproductive diseases.

African-specific molecular taxonomy of prostate cancer.

Prostate cancer is characterized by considerable geo-ethnic disparity. African ancestry is a significant risk factor, with mortality rates across sub-Saharan Africa of 2.7-fold higher than global averages1. The contributing genetic and non-genetic factors, and associated mutational processes, are unknown2,3. Here, through whole-genome sequencing of treatment-naive prostate cancer samples from 183 ancestrally (African versus European) and globally distinct patients, we generate a large cancer genomics resource for sub-Saharan Africa, identifying around 2 million somatic variants. Significant African-ancestry-specific findings include an elevated tumour mutational burden, increased percentage of genome alteration, a greater number of predicted damaging mutations and a higher total of mutational signatures, and the driver genes NCOA2, STK19, DDX11L1, PCAT1 and SETBP1. Examining all somatic mutational types, we describe a molecular taxonomy for prostate cancer differentiated by ancestry and defined as global mutational subtypes (GMS). By further including Chinese Asian data, we confirm that GMS-B (copy-number gain) and GMS-D (mutationally noisy) are specific to African populations, GMS-A (mutationally quiet) is universal (all ethnicities) and the African-European-restricted subtype GMS-C (copy-number losses) predicts poor clinical outcomes. In addition to the clinical benefit of including individuals of African ancestry, our GMS subtypes reveal different evolutionary trajectories and mutational processes suggesting that both common genetic and environmental factors contribute to the disparity between ethnicities. Analogous to gene-environment interaction-defined here as a different effect of an environmental surrounding in people with different ancestries or vice versa-we anticipate that GMS subtypes act as a proxy for intrinsic and extrinsic mutational processes in cancers, promoting global inclusion in landmark studies.