The Unrecognized Mortality Burden of Genetic Disorders in Infancy.

Objectives. To determine how deaths of infants with genetic diagnoses are described in national mortality statistics. Methods. We present a retrospective cohort study of mortality data, obtained from the National Death Index (NDI), and clinical data for 517 infants born from 2011 to 2017 who died before 1 year of age in the United States. Results. Although 115 of 517 deceased infants (22%) had a confirmed diagnosis of a genetic disorder, only 61 of 115 deaths (53%) were attributed to International Classification of Diseases, 10th Revision codes representing congenital anomalies or genetic disorders (Q00-Q99) as the underlying cause of death because of inconsistencies in death reporting. Infants with genetic diagnoses whose underlying causes of death were coded as Q00-Q99 were more likely to have chromosomal disorders than monogenic conditions (43/61 [70%] vs 18/61 [30%]; P < .001), which reflects the need for improved accounting for monogenic disorders in mortality statistics. Conclusions. Genetic disorders, although a leading cause of infant mortality, are not accurately captured by vital statistics. Public Health Implications. Expanded access to genetic testing and further clarity in death reporting are needed to describe properly the contribution of genetic disorders to infant mortality.

Hematopoietic Stem Cell Transplantation in Children with Inborn Errors of Immunity: a Multi-center Experience in Colombia.

PURPOSE: To characterize the pediatric population with inborn errors of immunity (IEI) that was treated with hematopoietic stem cell transplantation (HSCT) in three reference centers in Colombia. What have been the characteristics and outcomes of hematopoietic stem cell transplantation in pediatric patients with inborn errors of immunity in three reference care centers in Colombia between 2007 and 2018? METHODS: We conducted an observational, retrospective cohort study in children with a diagnosis of IEI who underwent HSCT between 2007 and 2018. RESULTS: Forty-seven patients were identified, and 5 were re-transplanted. Sixty-eight percent were male. The median age at diagnosis was 0.6 years, and for HSCT was 1.4 years. The most common diseases were chronic granulomatous disease (38%) followed by severe combined immune deficiencies (19%) and hemophagocytic lymphohistiocytosis (15%). Cord blood donors were the most used source of HSCT (44%). T cell-replete grafts from haploidentical donors using post-transplantation cyclophosphamide represent 37% of the cohort. All patients received conditioning, 62% with a non-myeloablative regimen. Calcineurin inhibitors were the main graft-versus-host disease prophylaxis (63.8%). Acute graft-versus-host disease developed in 35% of the total patients. The most frequent post-transplant infections were viral and fungal infections. The 1-year overall survival rates for the patients who received HSCT from identical, haploidentical, and cord sources were 80%, 72%, and 63%, respectively. The 5-year overall survival was 63%. CONCLUSIONS: HSCT is a curative treatment option for some IEI and can be performed with any donor type. Early and timely treatment in referral centers can improve survival.

Combined Utility of 25 Disease and Risk Factor Polygenic Risk Scores for Stratifying Risk of All-Cause Mortality.

While genome-wide association studies have identified susceptibility variants for numerous traits, their combined utility for predicting broad measures of health, such as mortality, remains poorly understood. We used data from the UK Biobank to combine polygenic risk scores (PRS) for 13 diseases and 12 mortality risk factors into sex-specific composite PRS (cPRS). These cPRS were moderately associated with all-cause mortality in independent data within the UK Biobank: the estimated hazard ratios per standard deviation were 1.10 (95% confidence interval: 1.05, 1.16) and 1.15 (1.10, 1.19) for women and men, respectively. Differences in life expectancy between the top and bottom 5% of the cPRS were estimated to be 4.79 (1.76, 7.81) years and 6.75 (4.16, 9.35) years for women and men, respectively. These associations were substantially attenuated after adjusting for non-genetic mortality risk factors measured at study entry (i.e., middle age for most participants). The cPRS may be useful in counseling younger individuals at higher genetic risk of mortality on modification of non-genetic factors.

Extended clinical and immunological phenotype and transplant outcome in CD27 and CD70 deficiency.

Biallelic mutations in the genes encoding CD27 or its ligand CD70 underlie inborn errors of immunity (IEIs) characterized predominantly by Epstein-Barr virus (EBV)-associated immune dysregulation, such as chronic viremia, severe infectious mononucleosis, hemophagocytic lymphohistiocytosis (HLH), lymphoproliferation, and malignancy. A comprehensive understanding of the natural history, immune characteristics, and transplant outcomes has remained elusive. Here, in a multi-institutional global collaboration, we collected the clinical information of 49 patients from 29 families (CD27, n = 33; CD70, n = 16), including 24 previously unreported individuals and identified a total of 16 distinct mutations in CD27, and 8 in CD70, respectively. The majority of patients (90%) were EBV+ at diagnosis, but only ∼30% presented with infectious mononucleosis. Lymphoproliferation and lymphoma were the main clinical manifestations (70% and 43%, respectively), and 9 of the CD27-deficient patients developed HLH. Twenty-one patients (43%) developed autoinflammatory features including uveitis, arthritis, and periodic fever. Detailed immunological characterization revealed aberrant generation of memory B and T cells, including a paucity of EBV-specific T cells, and impaired effector function of CD8+ T cells, thereby providing mechanistic insight into cellular defects underpinning the clinical features of disrupted CD27/CD70 signaling. Nineteen patients underwent allogeneic hematopoietic stem cell transplantation (HSCT) prior to adulthood predominantly because of lymphoma, with 95% survival without disease recurrence. Our data highlight the marked predisposition to lymphoma of both CD27- and CD70-deficient patients. The excellent outcome after HSCT supports the timely implementation of this treatment modality particularly in patients presenting with malignant transformation to lymphoma.

Catheter and Device Management of Inherited Cardiac Conditions.

This state-of-the art review discusses sudden cardiac death (SCD) risk stratification and prevention using implantable cardioverter defibrillator (ICD) therapy and the place of catheter ablation in the major inherited cardiomyopathies and primary arrhythmic syndromes. ICD therapy protects against SCD in many inherited cardiac conditions, particularly the cardiomyopathies in advanced stages, such as hypertrophic cardiomyopathy (HCM) and arrhythmogenic right ventricular cardiomyopathy (ARVC). However, they are not usually indicated in most patients with cardiac ion channelopathies, particularly long QT syndrome, since medical management is safe and preferable for most cases. The general exception is the secondary prevention setting following a cardiac arrest, where guidelines mostly support ICD therapy. However, in the case of catecholaminergic polymorphic ventricular tachycardia (CPVT), ICD therapy is less clear, with some studies indicating increased mortality when an ICD is used following a cardiac arrest, compared to optimal medical therapy alone. When ICDs are placed, they are commonly associated with morbidity, and do not reduce the burden of ventricular arrhythmias (VA), such that multiple ICD shocks can ensue. Catheter ablation has been shown to reduce VA burden, VA related symptoms and ICD therapy in correctly identified patients in each condition. Its role is particularly important in cases where monomorphic ventricular tachycardia (VT) is prevalent, such as Lamin-related dilated cardiomyopathy (DCM) and ARVC. Evidence is growing to support the use of catheter ablation to treat premature ventricular contraction (PVC) induced VF in the setting of long and short QT syndromes, CPVT, idiopathic VF and early repolarisation syndromes. In Brugada syndrome, epicardial substrate ablation can even apparently eliminate the electrocardiographic (ECG) phenotype and reduce VA burden during follow-up.

Hypertrophic Cardiomyopathy: Challenging the Status Quo?

Hypertrophic cardiomyopathy (HCM) is the most common cardiovascular genetic disorder. While our mechanistic understanding has been informed by elegant gene discovery studies that led to the term "disease of the sarcomere", more recent investigations have challenged the single-gene hypothesis. Multimodality imaging has allowed better phenotyping to facilitate early diagnosis, identify treatable phenocopies, and guide management. While HCM remains an important cause of sudden death, recent studies have reported a substantial cumulative burden of heart failure and atrial fibrillation in middle-aged and older individuals. Nonetheless, improvements in risk stratification have allowed early intervention to transition HCM from being a common cause of sudden death in the young to a treatable chronic disease.

Infant mortality: the contribution of genetic disorders.

OBJECTIVE: To determine the proportion of infant deaths occurring in the setting of a confirmed genetic disorder. STUDY DESIGN: A retrospective analysis of the electronic medical records of infants born from 1 January, 2011 to 1 June, 2017, who died prior to 1 year of age. RESULTS: Five hundred and seventy three deceased infants were identified. One hundred and seventeen were confirmed to have a molecular or cytogenetic diagnosis in a clinical diagnostic laboratory and an additional seven were diagnosed by research testing for a total of 124/573 (22%) diagnosed infants. A total of 67/124 (54%) had chromosomal disorders and 58/124 (47%) had single gene disorders (one infant had both). The proportion of diagnoses made by sequencing technologies, such as exome sequencing, increased over the years. CONCLUSIONS: The prevalence of confirmed genetic disorders within our cohort of infant deaths is higher than that previously reported. Increased efforts are needed to further understand the mortality burden of genetic disorders in infancy.

Outcomes of Hematopoietic Cell Transplantation in Patients with Germline SAMD9/SAMD9L Mutations.

Germline mutations in SAMD9 and SAMD9L genes cause MIRAGE (myelodysplasia, infection, restriction of growth, adrenal hypoplasia, genital phenotypes, and enteropathy) (OMIM: *610456) and ataxia-pancytopenia (OMIM: *611170) syndromes, respectively, and are associated with chromosome 7 deletions, myelodysplastic syndrome (MDS), and bone marrow failure. In this retrospective series, we report outcomes of allogeneic hematopoietic cell transplantation (HCT) in patients with hematologic disorders associated with SAMD9/SAMD9L mutations. Twelve patients underwent allogeneic HCT for MDS (n = 10), congenital amegakaryocytic thrombocytopenia (n = 1), and dyskeratosis congenita (n = 1). Exome sequencing revealed heterozygous mutations in SAMD9 (n = 6) or SAMD9L (n = 6) genes. Four SAMD9 patients had features of MIRAGE syndrome. Median age at HCT was 2.8 years (range, 1.2 to 12.8 years). Conditioning was myeloablative in 9 cases and reduced intensity in 3 cases. Syndrome-related comorbidities (diarrhea, infections, adrenal insufficiency, malnutrition, and electrolyte imbalance) were present in MIRAGE syndrome cases. One patient with a familial SAMD9L mutation, MDS, and morbid obesity failed to engraft and died of refractory acute myeloid leukemia. The other 11 patients achieved neutrophil engraftment. Acute post-transplant course was complicated by syndrome-related comorbidities in MIRAGE cases. A patient with SAMD9L-associated MDS died of diffuse alveolar hemorrhage. The other 10 patients had resolution of hematologic disorder and sustained peripheral blood donor chimerism. Ten of 12 patients were alive with a median follow-up of 3.1 years (range, 0.1 to 14.7 years). More data are needed to refine transplant approaches in SAMD9/SAMD9L patients with significant comorbidities and to develop guidelines for their long-term follow-up.

Familial Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC), although a rare disease, has a poor prognosis. With 5-year overall survival of 8%, there is a critical need to detect PDAC early or at a premalignant stage. Current screening methods are largely imaging based, but a more focused screening approach based on modifiable and nonmodifiable risk factors may improve the efficacy and likely outcomes of screening. In addition, the pathologic mechanisms that lead to the development of PDAC are discussed in an effort to further understand the targets of pancreatic cancer screening. The focus of this article will be inherited pancreatic cancer syndromes and familial pancreatic cancer, which together compose up to 10% of PDAC. Understanding the methods and targets of PDAC screening in high-risk individuals may translate to improved morbidity and mortality.

The Outcome of Allogeneic Hematopoietic Stem Cell Transplantation for Inherited Diseases Is Influenced by HLA Match, Year of Transplantation, and Immunized Female Donor.

BACKGROUND: For many inborn errors of metabolism (IEM), allogeneic hematopoietic stem cell transplantation (HSCT) is the only cure. METHODS: We report the outcome in 160 patients with inherited diseases, who were treated with HSCT in 3 decades. Median age was 3 years (range 0.1-63). Grafts were from matched related donors (MRDs, 56), matched unrelated donors (MUDs, 66), or HLA-mismatched donors (38). RESULTS: Graft failure (GF) occurred in 26 patients (16%), severe acute graft-versus-host disease (GVHD) in 9 (6%), and chronic GVHD in 23 (12%). Ten-year survival was 64% before the year 2000 and 86% after that (P = 0.01). Ten-year survival for MRD grafts was 90%, as opposed to 79% for MUD grafts and 56% for HLA-mismatched grafts (P = 0.03). In multivariate analysis, GF was associated with having an HLA-mismatched donor (P < 0.05) or MUD (P = 0.015) and with reduced-intensity conditioning (P < 0.01). Death was associated with year of transplant (P = 0.015), having an HLA-mismatched donor (P < 0.001), and being a male recipient from an immune female donor (P = 0.05). CONCLUSIONS: The outcome after HSCT for IEM depends on HLA match, year and immune female donor.

ESTIMATING THE HEALTH AND SOCIOECONOMIC EFFECTS OF COUSIN MARRIAGE IN SOUTH ASIA.

The effects of marriage between biological relatives on the incidence of childhood genetic illness and mortality are of major policy significance, as rates of consanguinity exceed 50% in various countries. Empirical research on this question is complicated by the fact that consanguinity is often correlated with poverty and other unobserved characteristics of households, which may have independent effects on mortality. This study has developed an instrumental variables empirical strategy to re-examine this question, based on the concept that the availability of unmarried cousins of the opposite gender at the time of marriage creates quasi-random variation in the propensity to marry consanguineously. Using primary data collected in Bangladesh in 2006-07 and Pakistan in 2009-10, the study found that previous estimates of the impact of consanguinity on child health were biased and falsely precise. The study also empirically investigated the social and economic causes of consanguinity (including marital quality) and concludes that marrying a cousin can have positive economic effects for one's natal family, by allowing deferral of dowry payments until after marriage.

Effect of Ascertainment Bias on Estimates of Patient Mortality in Inherited Cardiac Diseases.

BACKGROUND: Accurate estimates of survival are indispensable for cardiologists, clinical geneticists, and genetic counselors dealing with families with an inherited cardiac disease. However, a bias towards a more severe disease with a worse outcome in the first publications may not accurately represent the actual survival forecast. We, therefore, evaluated the effect of ascertainment bias on survival in 3 different inherited cardiac diseases (idiopathic ventricular fibrillation, SCN5A overlap syndrome, and arrhythmogenic cardiomyopathy) caused by a founder mutation. METHODS: We collected mortality data from mutation-positive subjects with either DPP6-associated idiopathic ventricular fibrillation, SCN5A overlap syndrome, and PLN-R14del-mediated arrhythmogenic cardiomyopathy >2 to 10 years of ongoing clinical/cascade genetic screening. RESULTS: The median age of survival in DPP6 mutation-positive subjects increased from 44.6 years in the original cohort from 2008 (n=60; 95% CI, 36.8-52.4 years) to 68.2 years in the extended cohort from 2012 (n=235; 95% CI, 64.6-71.7 years; P<0.001). In the SCN5A overlap syndrome, survival increased from 56.1 years in 1999 (n=86; 95% CI, 48.0-64.2 years) to 69.7 years in 2009 (n=197; 95% CI, 61.3-78.2 years; P=0.049). In PLN-R14del positive patients, the median age of survival increased from 63.5 years in 2010 (n=89; 95% CI, 59.1-68.0 years) to 65.2 years in 2012 (n=370; 95% CI, 62.0-68.3 years; P=0.046). CONCLUSIONS: The median age of survival in 3 different inherited cardiac diseases with an established pathogenic substrate significantly increased once genetic testing and cascade screening extended, after the first publication that elucidated the discovery of the disease-susceptibility gene/mutation. This underscores the direct and negative influence of ascertainment bias on survival forecasts and the importance of ongoing clinical/genetic follow-up to establish the most accurate disease prognosis for genetically mediated heart diseases.

Non-parametric estimation of survival in age-dependent genetic disease and application to the transthyretin-related hereditary amyloidosis.

In genetic diseases with variable age of onset, survival function estimation for the mutation carriers as well as estimation of the modifying factors effects are essential to provide individual risk assessment, both for mutation carriers management and prevention strategies. In practice, this survival function is classically estimated from pedigrees data where most genotypes are unobserved. In this article, we present a unifying Expectation-Maximization (EM) framework combining probabilistic computations in Bayesian networks with standard statistical survival procedures in order to provide mutation carrier survival estimates. The proposed approach allows to obtain previously published parametric estimates (e.g. Weibull survival) as particular cases as well as more general Kaplan-Meier non-parametric estimates, which is the main contribution. Note that covariates can also be taken into account using a proportional hazard model. The whole methodology is both validated on simulated data and applied to family samples with transthyretin-related hereditary amyloidosis (a rare autosomal dominant disease with highly variable age of onset), showing very promising results.

Mitochondrial DNA m.3243A > G heteroplasmy affects multiple aging phenotypes and risk of mortality.

Mitochondria contain many copies of a circular DNA molecule (mtDNA), which has been observed as a mixture of normal and mutated states known as heteroplasmy. Elevated heteroplasmy at a single mtDNA site, m.3243A > G, leads to neurologic, sensory, movement, metabolic, and cardiopulmonary impairments. We measured leukocyte mtDNA m.3243A > G heteroplasmy in 789 elderly men and women from the bi-racial, population-based Health, Aging, and Body Composition Study to identify associations with age-related functioning and mortality. Mutation burden for the m.3243A > G ranged from 0-19% and elevated heteroplasmy was associated with reduced strength, cognitive, metabolic, and cardiovascular functioning. Risk of all-cause, dementia and stroke mortality was significantly elevated for participants in the highest tertiles of m.3243A > G heteroplasmy. These results indicate that the accumulation of a rare genetic disease mutation, m.3243A > G, manifests as several aging outcomes and that some diseases of aging may be attributed to the accumulation of mtDNA damage.

Genetic disorders and mortality in infancy and early childhood: delayed diagnoses and missed opportunities.

PURPOSE: Infants admitted to a level IV neonatal intensive care unit (NICU) who do not survive early childhood are a population that is probably enriched for rare genetic disease; we therefore characterized their genetic diagnostic evaluation. METHODS: This is a retrospective analysis of infants admitted to our NICU between 1 January 2011 and 31 December 2015 who were deceased at the time of records review, with age at death less than 5 years. RESULTS: A total of 2,670 infants were admitted; 170 later died. One hundred six of 170 (62%) had an evaluation for a genetic or metabolic disorder. Forty-seven of 170 (28%) had laboratory-confirmed genetic diagnoses, although 14/47 (30%) diagnoses were made postmortem. Infants evaluated for a genetic disorder spent more time in the NICU (median 13.5 vs. 5.0 days; p = 0.003), were older at death (median 92.0 vs. 17.5 days; p < 0.001), and had similarly high rates of redirection of care (86% vs. 79%; p = 0.28). CONCLUSION: Genetic disorders were suspected in many infants but found in a minority. Approximately one-third of diagnosed infants died before a laboratory-confirmed genetic diagnosis was made. This highlights the need to improve genetic diagnostic evaluation in the NICU, particularly to support end-of-life decision making.

Can sudden cardiac death in the young be predicted and prevented? Lessons from autopsy for the emergency physician. / ¿Se puede predecir y prevenir la muerte súbita cardiaca en sujetos jóvenes? Algunas indicaciones para el urgenciólogo.

OBJECTIVES: Sudden unexpected death in the young, though rare, is devastating for both the family and the community. Although only 1.3 to 8.5 cases of sudden cardiac death (SCD) occur per 100 000 young people, autopsy is often inconclusive. Many causes of SCD are related to autosomal dominant inherited risk, however; therefore, answers are important for survivors. Causes of autopsy-positive SCD in young patients include hypertrophic cardiomyopathy and arrhythmogenic right ventricular dysplasia. Autopsy-negative SCD has been related to inherited arrhythmogenic causes such as long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, Wolff- Parkinson-White syndrome, and idiopathic ventricular fibrillation. The important question for the emergency physician is how SCD can be predicted and prevented in the young so that there is no need for an autopsy.

ES: La muerte súbita e inesperada en jóvenes es un evento raro pero devastador. Aunque su incidencia es baja, se registran de 1,3 a 8,5 casos de muerte súbita cardiaca (MSC) por cada 100.000 jóvenes y se asocia frecuentemente con una autopsia negativa. Muchas de las causas de la MSC con autopsia negativa se heredan de forma autosómica dominante. Algunas causas de MSC con autopsia positiva en pacientes jóvenes incluyen la miocardiopatía hipertrófica (MCH) y la displasia arritmogénica de ventriculo derecho. Las causas de autopsia negativa incluyen causas arritmogénicas heredadas, como el síndrome de QT largo, el síndrome de Brugada, la taquicardia ventricular polimórfica catecolaminérgica, el syndrome de Wolff-Parkinson-White (WPW) y la fibrilación ventricular idiopática. La pregunta importante para los profesionales de urgencias es: ¿cómo podemos predecir y prevenir la MSC en los jóvenes antes de la autopsia?

Survival time with pacemaker implantation for dogs diagnosed with persistent atrial standstill.

OBJECTIVES: To evaluate survival time in dogs with persistent atrial standstill after pacemaker implantation and to compare the survival times for cardiac-related vs. non-cardiac deaths. Secondary objectives were to evaluate the effects of breed and the presence of congestive heart failure (CHF) at the time of diagnosis on survival time. ANIMALS: Twenty dogs with persistent atrial standstill and pacemaker implantation. METHODS: Medical records were searched to identify dogs diagnosed with persistent atrial standstill based on electrocardiogram that underwent pacemaker implantation. Survival after pacemaker implantation was analyzed using the Kaplan-Meier method. RESULTS: The median survival time after pacemaker implantation for all-cause mortality was 866 days. There was no significant difference (p=0.573) in median survival time for cardiac (506 days) vs. non-cardiac deaths (400 days). The presence of CHF at the time of diagnosis did not affect the survival time (P=0.854). No difference in median survival time was noted between breeds (P=0.126). CONCLUSIONS: Dogs with persistent atrial standstill have a median survival time of 866 days with pacemaker implantation, though a wide range of survival times was observed. There was no difference in the median survival time for dogs with cardiac-related deaths and those without. Patient breed and the presence of CHF before pacemaker implantation did not affect median survival time.

Use of Extracorporeal Membrane Oxygenation and Mortality in Pediatric Cardiac Surgery Patients With Genetic Conditions: A Multicenter Analysis.

OBJECTIVE: Congenital heart disease is commonly a manifestation of genetic conditions. Surgery and/or extracorporeal membrane oxygenation were withheld in the past from some patients with genetic conditions. We hypothesized that surgical care of children with genetic conditions has increased over the last decade, but their cardiac extracorporeal membrane oxygenation use remains lower and mortality greater. DESIGN: Retrospective cohort study. SETTING: Patients admitted to the Pediatric Health Information System database 18 years old or younger with cardiac surgery during 2003-2014. Genetic conditions identified by International Classification of Diseases, 9th Edition codes were grouped as follows: trisomy 21, trisomy 13 or 18, 22q11 deletion, and all "other" genetic conditions and compared with patients without genetic condition. PATIENTS: A total of 95,253 patients met study criteria, no genetic conditions (85%), trisomy 21 (10%), trisomy 13 or 18 (0.2%), 22q11 deletion (1%), and others (5%). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Annual surgical cases did not vary over time. Compared to patients without genetic conditions, trisomy 21 patients, extracorporeal membrane oxygenation use was just over half (odds ratio, 0.54), but mortality with and without extracorporeal membrane oxygenation were similar. In trisomy 13 or 18 patients, extracorporeal membrane oxygenation use was similar to those without genetic condition, but all five treated with extracorporeal membrane oxygenation died. 22q11 patients compared with those without genetic condition had similar extracorporeal membrane oxygenation use, but greater odds of extracorporeal membrane oxygenation mortality (odds ratio, 3.44). Other genetic conditions had significantly greater extracorporeal membrane oxygenation use (odds ratio, 1.22), mortality with extracorporeal membrane oxygenation (odds ratio, 1.42), and even greater mortality odds without (odds ratio, 2.62). CONCLUSIONS: The proportion of children undergoing cardiac surgery who have genetic conditions did not increase during the study. Excluding trisomy 13 or 18, all groups of genetic conditions received and benefited from extracorporeal membrane oxygenation, although extracorporeal membrane oxygenation mortality was greater for those with 22q11 deletion and other genetic conditions.

Genetics of consanguinity and inbreeding in health and disease.

CONTEXT: Inbreeding increases the level of homozygotes for autosomal recessive disorders and is the major objective in clinical studies. The prevalence of consanguinity and the degree of inbreeding vary from one population to another depending on ethnicity, religion, culture and geography. Global epidemiological studies have revealed that consanguineous unions have been significantly associated with increased susceptibility to various forms of inherited diseases. OBJECTIVE: The study aimed to determine the role of consanguinity in human health and to highlight the associated risks for various diseases or disorders. METHODS: PubMed and Google Scholar search engines were used to explore the published literature on consanguinity and its associated risks using the key words "consanguinity", "prevalence", "inbreeding depression", "coefficient of inbreeding", "child health", "mortality", "human health", "homozygosity" and "complex diseases" in different combinations. The studies were screened for eligibility on the basis of their epidemiological relevance. RESULTS: This comprehensive assessment highlights the deleterious consequences in populations with a higher prevalence of consanguinity among different countries worldwide. CONCLUSIONS: To avoid the inbreeding load there is the need to improve socioeconomic and educational status and to increase public awareness of reproductive health and anticipated deleterious effects. Pre-marital and pre-conception counselling of consanguineous populations should be an integral part of health policy to train people and make people aware of its harmful consequences. Furthermore, runs of homozygosity (ROH) and whole-exome sequencing (WES) are useful tools in exploring new genomic signatures for the cause of inbreeding depression.

Pleiotropic Associations of Allelic Variants in a 2q22 Region with Risks of Major Human Diseases and Mortality.

Gaining insights into genetic predisposition to age-related diseases and lifespan is a challenging task complicated by the elusive role of evolution in these phenotypes. To gain more insights, we combined methods of genome-wide and candidate-gene studies. Genome-wide scan in the Atherosclerosis Risk in Communities (ARIC) Study (N = 9,573) was used to pre-select promising loci. Candidate-gene methods were used to comprehensively analyze associations of novel uncommon variants in Caucasians (minor allele frequency~2.5%) located in band 2q22.3 with risks of coronary heart disease (CHD), heart failure (HF), stroke, diabetes, cancer, neurodegenerative diseases (ND), and mortality in the ARIC study, the Framingham Heart Study (N = 4,434), and the Health and Retirement Study (N = 9,676). We leveraged the analyses of pleiotropy, age-related heterogeneity, and causal inferences. Meta-analysis of the results from these comprehensive analyses shows that the minor allele increases risks of death by about 50% (p = 4.6×10-9), CHD by 35% (p = 8.9×10-6), HF by 55% (p = 9.7×10-5), stroke by 25% (p = 4.0×10-2), and ND by 100% (p = 1.3×10-3). This allele also significantly influences each of two diseases, diabetes and cancer, in antagonistic fashion in different populations. Combined significance of the pleiotropic effects was p = 6.6×10-21. Causal mediation analyses show that endophenotypes explained only small fractions of these effects. This locus harbors an evolutionary conserved gene-desert region with non-coding intergenic sequences likely involved in regulation of protein-coding flanking genes ZEB2 and ACVR2A. This region is intensively studied for mutations causing severe developmental/genetic disorders. Our analyses indicate a promising target region for interventions aimed to reduce risks of many major human diseases and mortality.