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.

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.

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.

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.

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.

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.

Can sudden cardiac death in the young be predicted and prevented? Lessons from autopsy for the emergency physician

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.

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.

Biomedical research and medical care are traditionally focused on individual health conditions in order to postpone, ameliorate, or prevent the accumulation of morbidities in late life. An attractive idea is to find factors, which could reduce burden of not just one disease but a major subset of them to efficiently extend healthy lifespan. Here we focus on the analyses of genetic predisposition to risks of major human age-related diseases and mortality. The analyses highlight a locus in band 2q22.3 associated with risks of coronary heart disease, heart failure, stroke, diabetes, cancer, neurodegenerative diseases, and death. Our analyses indicate a promising target region for interventions aimed to reduce risks of many major human diseases and mortality.

Survival of 4 dogs with persistent atrial standstill treated by pacemaker implantation

Pacemakers were implanted in 4 client-owned female dogs which had persistent atrial standstill. Three dogs were alive after 14 to 39 months and 1 dog was euthanized after 10.5 years. This report demonstrates that some dogs with persistent atrial standstill can survive for extended time periods.

[CHEK2-associated hereditary breast cancer]

CHEK2 is classified as a moderate-penetrance gene for hereditary breast cancer (BC). In Russia, CHEK2 mutations hold second position in the list of BC-predisposing gene defects after BRCAl, and include CHEK2 1100deIC, de15395, and IVS2+lG>A gene-inactivating alleles. CHEK2-driven breast carcinomas are generally characterized by poor prognosis and low sensitivity to the conventional therapeutic regimens. CHEK2 testing needs to be incorporated into routine clinical practice owing its overt clinical significance.

Newborn screening and the era of medical genomics

Across the span of the last 75+ years, technological and conceptual advances in genetics have found rapid implementation at the beginning of human life. From karyotype testing, to molecular cytogenetics, to gene panel testing, and now to whole exome and whole genome sequencing, each iterative expansion of our capability to acquire genetic data on the next generation has been implemented quickly in the clinical setting. In tandem, our continuously expanding ability to acquire large volumes of genetic data has generated its own challenges in terms of interpretation, clinical utility of the information, and concerns over privacy and discrimination; for the first time, we are faced with the possibility of having complete access to our genetic data from birth, if not shortly after conception. Here, we discuss the evolution of the field toward this new reality and we consider the potentially far-reaching consequences and, at present, an unclear path toward developing best practices for implementation.

Umbilical cord blood banks. Ethical aspects. Public versus private banks

The creation of umbilical cord blood (UCB) banks raises interesting medical, social, economic and ethical issues. This paper reviews the ethical problems specifically. In this respect, it evaluates: a) whether there are advantages to the use of UCB compared to bone marrow, b) whether or not it is ethical to create UCB banks, c) whether their creation is ethically acceptable in terms of their clinical usefulness or d) the use made of them for therapeutic purposes, and finally e) whether their creation is ethically justified from a cost/profitability point of view. We focus primarily on evaluating the ethical controversy between public and private banks, particularly on whether it is ethical to bank autologous blood in private UCB banks, on the basis of its limited possibilities for use by the cord blood donor. We can conclude that, from an ethical point of view, autologous blood banks have limited acceptance among specialised researchers, scientific societies and other public institutions. Therefore, we believe that it is ethically more acceptable to support the creation of public UCB banks for medical and social reasons and, above all, based on the principle of justice and human solidarity. Nevertheless, there is no definitive ethical argument why a couple, according to their autonomy and freedom, cannot bank their child's UCB in a private bank. An equally acceptable solution could be the creation of mixed banks, such as that proposed by the Virgin Health Bank or like the Spanish system where autologous samples can be stored in public banks but with the proviso that if at any time the stored sample is required by any person other than the donor, it would have to be given to them.

A single-center experience in 20 patients with infantile malignant osteopetrosis

Infantile malignant osteopetrosis (IMO) includes various genetic disorders that affect osteoclast development and/or function. Genotype-phenotype correlation studies in IMO have been hampered by the rarity and heterogeneity of the disease and by the severity of the clinical course, which often leads to death early in life. We report on the clinical and molecular findings and treatment in 20 consecutive patients (11 males, nine females) with IMO, diagnosed at a single center in the period 1991-2008. Mean age at diagnosis was 3.9 months, and mean follow-up was 66.75 months. Mutations in TCIRG1, OSTM1, ClCN7, and TNFRSF11A genes were detected in nine, three, one, and one patients, respectively. Six patients remain genetically undefined. OSTM1 and ClCN7 mutations were associated with poor neurologic outcome. Among nine patients with TCIRG1 defects, six presented with hypogammaglobulinemia, and one showed primary pulmonary hypertension. Fourteen patients received hematopoietic cell transplantation; of these, nine are alive and eight of them have evidence of osteoclast function. These data may provide a basis for informed decisions regarding the care of patients with IMO.

Highly diverged MHC class I mismatches are acceptable for haematopoietic stem cell transplantation

A fully major histocompatilbility complex (MHC) matched donor is not available for the majority of patients in need of a haematopoietic stem cell transplantation (SCT), which illustrates the need for a tool to define acceptable MHC disparities. Previously, we noticed that a variety of single MHC class I mismatched allogeneic donor-recipient pairs did not elicit an allogeneic cytotoxic-lymphocyte (CTL) response in vitro if the MHC amino-acid sequences had five or more differences in the alpha-helices plus five or more differences in the beta-sheet (> or =5alpha5beta) (7). To address the clinical relevance of this observation, we analysed CTL precursor (CTLp) assay outcome and SCT outcome in 53 Dutch recipients of a single MHC class I mismatched graft from an unrelated donor. Overall patient survival was 44% after 4 years. In multivariate analysis, recipients of a > or =5alpha5beta mismatched graft with negative CTLp frequencies in vitro before transplantation demonstrated superior survival: survival at 4 years was 80% as compared to 47% in recipients of other mismatched grafts with negative CTLp frequencies (hazard ratio=0.131; 95% CI=(0.03-0.61); P=0.009). This option of acceptable mismatches may enlarge the pool of potentially acceptable stem cell donors.

A defect in dolichol phosphate biosynthesis causes a new inherited disorder with death in early infancy

The following study describes the discovery of a new inherited metabolic disorder, dolichol kinase (DK1) deficiency. DK1 is responsible for the final step of the de novo biosynthesis of dolichol phosphate. Dolichol phosphate is involved in several glycosylation reactions, such as N-glycosylation, glycosylphosphatidylinositol (GPI)-anchor biosynthesis, and C- and O-mannosylation. We identified four patients who were homozygous for one of two mutations (c.295T-->A [99Cys-->Ser] or c.1322A-->C [441Tyr-->Ser]) in the corresponding hDK1 gene. The residual activity of mutant DK1 was 2%-4% when compared with control cells. The mutated alleles failed to complement the temperature-sensitive phenotype of DK1-deficient yeast cells, whereas the wild-type allele restored the normal growth phenotype. Affected patients present with a very severe clinical phenotype, with death in early infancy. Two of the patients died from dilative cardiomyopathy.

Lost in transition: challenges in the expanding field of adult genetics

It is increasingly clear that medical genetics has broad relevance in adult clinical medicine. More adult patients with genetic conditions are being recognized, genetic testing for adult-onset genetic conditions is expanding, and children with genetic conditions are now more likely to survive to adulthood. While the number of patients who could benefit from medical genetic services increases, adult care providers are less well educated about clinical genetics and are not sufficiently prepared to meet the growing needs of this population. Genetics professionals may also be ill-suited for this challenge, since geneticists and genetic counselors have traditionally had greater experience in pediatric and prenatal settings. Communication between primary care physicians who treat adults and the genetics community is currently suboptimal and the identification and subsequent referral of adult patients for genetic services need improvement. Finally, published guidelines that address how to deliver genetic services to adult patients are unavailable for many genetic conditions. In this article we address the challenges of transitioning genetics services from traditional, and largely pediatric-based models to paradigms that can best address the needs of adult patients with genetic conditions. Potential solutions and the practicality of implementation of a team-based approach to adult genetic medicine, including the application of genetic counseling, are also discussed.

Engraftment and survival following hematopoietic stem cell transplantation for osteopetrosis using a reduced intensity conditioning regimen

Autosomal recessive osteopetrosis (OP) is a disease characterized by osteoclast dysfunction, leading to multisystem morbidity and death of most affected children. Hematopoietic stem cell transplantation (HSCT) is the treatment of choice for OP, but this patient population is particularly prone to post-transplant complications and death after myeloablative conditioning. To determine the potential of achieving improved overall outcomes in these patients by decreasing pre-transplant mortality, we investigated engraftment and survival following a reduced intensity regimen including busulfan, fludarabine and total lymphoid irradiation. We report outcomes in 11 patients. All six patients who received a bone marrow or peripheral stem cell graft engrafted with >75% donor chimerism. In contrast, all five recipients of unrelated cord blood as a stem cell source for a first graft failed to demonstrate donor hematopoietic chimerism. The day 100 and 6-month mortality was low at 9%. One year after HSCT, six of 11 patients (55%) were surviving. Our data suggest that this regimen results in low peri-transplant mortality without compromising engraftment when a marrow or peripheral stem cell graft is used. An umbilical cord blood graft, however, should be used with caution for patients with OP when this or a similar reduced intensity regimen is used.

Infant mortality, ethnicity, and genetically determined disorders in The Netherlands

BACKGROUND

Infant mortality of ethnic minorities in The Netherlands (10% of the population) is twice as high as in the indigenous Dutch population. Causes of death are different for the diverse migrant groups.

METHODS

Hospital records of nearly 600 infants who died in the four major cities between 1995 and 1998 were analysed according to the cause of death, ethnicity, and possible heredity.

RESULTS

There was a four to five times higher proportion of hereditary causes of death in the Moroccan and Turkish population, compared with the Surinamese/Antillians and indigenous Dutch.

CONCLUSIONS

This might be explained by a high inbreeding coefficient as three-quarters of the marriage partners are recruited from the home villages and between a quarter and a third of these marriages are between first cousins. Health promotion activities in The Netherlands have not been successful so far. Preconception genetic counselling might help in reducing these differences.

Riesgos competitivos de muerte y equilibrio de Hardy-Weinberg en estudios de casos y controles sobre asociación entre genes y enfermedades

OBJECTIVE

To study the impact of competing risks on Hardy-Weinberg equilibrium and their consequences in case-control studies of gene-late onset disease association.

METHODS

Based on a population born in Hardy-Weinberg equilibrium for a particular gene, the genetic composition when the gene is associated with a lethal early-onset disease and its consequences on a late-onset disease can be deduced. Odds ratios estimates are unbiased in case-control studies when controls are sampled by density, even if the controls are in Hardy-Weinberg disequilibrium.

RESULTS

An example in which a mutant gene is associated with early mortality is presented, producing a departure from Hardy-Weinberg equilibrium; as a result, controls in later ages are in disequilibrium, producing an odds ratio equal to 1.61.

CONCLUSION

Although the main causes of Hardy-Weinberg disequilibrium in controls are selection bias or genotyping error, a competing risk of death associated with the mutant gene would also result in Hardy-Weinberg disequilibrium among controls.

Impact of HLA matching on outcome of hematopoietic stem cell transplantation in children with inherited diseases: a single-center comparative analysis of genoidentical, haploidentical or unrelated donors

SUMMARY

Hematological inherited diseases can be cured by hematopoietic stem cell transplantation (HSCT) from an human leukocyte antigen (HLA)-identical sibling donor (MSD), but the outcome of unrelated donors (URD) or haploidentical donors (HMD) has been a cause of concern. In all, 94 children affected with inherited diseases underwent HSCT at a single center using MSD (group A, n=31), URD (group B, n=23) or HMD (group C, n=40). There was no difference in the rate of engraftment or in the incidence of grades III-IV acute graft-versus-host disease (GVHD) between the groups. Survival rate was 80.6% in group A, 62.5% in group B and 47.5% in group C (P=0.023). In group B, survival rate was 73.7% in the subgroup with zero or one class I mismatch, and 25% in the subgroup with two or more class I mismatches (P=0.04). In group C, survival rate was 83.3% in the 9/10-identical subgroup, 64.3% in the seven or 8/10 subgroup, and 25% in the five or 6/10 subgroup (P=0.0007). Thus, engraftment, incidence of GVHD and survival are similar in recipients of grafts from MSD, URD with 0-1 class I-mismatch, or HMD with at least 7/10 HLA matches. The low success of HSCT using more disparate donors suggests reserving them for patients with very poor prognosis.

Contribution of malformations and genetic disorders to mortality in a children's hospital

Malformations and genetic disorders are the leading cause of infant mortality in the US. Many malformations have a genetic basis due to genic, chromosomal, or multifactorial causation. We have studied the proportion of pediatric cases in a university-affiliated children's hospital that died of malformations and genetic disorders. We reviewed, retrospectively, deaths over a 4 year period (1994-1998) at Primary Children's Medical Center (PCMC), a university-affiliated tertiary children's referral hospital in Utah. The age at death and the cause of death were recorded for each case. We analyzed 523 cases; 180 (34.4%) deaths were due to malformations and genetic disorders. Of those 180, 30 (16.7%) had chromosome anomalies, 21 (11.7%) had a recognizable malformation syndrome, 118 (65.6%) had a malformation of unknown cause, and 11 (6.1%) had some other genetic disorder. One hundred and twenty-two (23.3%) deaths were due to trauma (accidental and non-accidental). Seventy-nine (15.1%) deaths were due to short gestation or perinatal complications. Forty-five (8.6%) deaths were due to an infectious disease and 45 (8.6%) from neoplasms. Thirteen (2.5%) were diagnosed for sudden infant death "syndrome." Twelve (2.3%) patients with malformations and/or genetic disorders died of an acquired condition not clearly related to the underlying disorder. Seven (1.3%) patients died of an unknown cause and 20 (3.8%) patients died of other specified conditions. In addition, 51.0% patients (age <1 year) died of a malformation and/or genetic disorder. Genetic disorders and malformations are a substantial cause of mortality in a referral pediatric hospital. Knowledge of the impact of genetic diseases on mortality is important for the integration of preventive measures and health care strategies to care effectively for patients and their families. This information emphasizes the importance of further study of whether or not early recognition influences mortality rate and management.

The impact of congenital malformations and Mendelian diseases on infant mortality in Israel

BACKGROUND

Infant mortality in Israel is twofold higher among non-Jews than Jews.

OBJECTIVES

To determine the impact of congenital malformations and Mendelian diseases on infant mortality.

METHODS

We compared the causes of infant mortality in a 4 year period among Jewish and non-Jewish Israeli citizens. Classification was done by analyzing all the death reports according to whether or not the child had any known major malformation, Mendelian disease and/or a syndrome, irrespective of the immediate cause of death.

RESULTS

The infant mortality among non-Jews was double that among Jews (9 versus 4.4 per 1,000 live births). The rate of children with malformations/genetic syndromes was 3.1 times higher among non-Jews than among Jews (2.94 vs. 1.25 per 1,000 live births). The most significant difference was in the rate of Mendelian diseases, which were 8.3 times more frequent in non-Jewish children (0.16 vs. 1.33 per 1,000 live births respectively). A Mendelian disease was diagnosed in almost 15% of the non-Jewish infants and in less than 5% of the Jewish infants.

CONCLUSIONS

The most striking difference between the Jewish and non-Jewish infants was the incidence of congenital malformations and Mendelian diseases parallel to the differences in the consanguinity rates between the two populations.

Fractional populations in multiple gene inheritance

MOTIVATION

With complete knowledge of the human genome sequence, one of the most interesting tasks remaining is to understand the functions of individual genes and how they communicate. Using the information about genes (locus, allele, mutation rate, fitness, etc.), we attempt to explain population demographic data. This population evolution study could complement and enhance biologists' understanding about genes.

RESULTS

We present a general approach to study population genetics in complex situations. In the present approach, multiple allele inheritance, multiple loci inheritance, natural selection and mutations are allowed simultaneously in order to consider a more realistic situation. A simulation program is presented so that readers can readily carry out studies with their own parameters. It is shown that the multiplicity of the loci greatly affects the demographic results of fractional population ratios. Furthermore, the study indicates that some high infant mortality rates due to congenital anomalies can be attributed to multiple loci inheritance.

AVAILABILITY

The simulation program can be downloaded from http://won.hongik.ac.kr/~mhchung/index_files/yapop.htm. In order to run this program, one needs Visual Studio.NET platform, which can be downloaded from http://msdn.microsoft.com/netframework/downloads/default.asp.

Congenital diaphragmatic hernia in 120 infants treated consecutively with permissive hypercapnea/spontaneous respiration/elective repair

BACKGROUND/PURPOSE

Poor prognosis (approximately 50% survival rate and significant morbidity) traditionally has been associated with congenital diaphragmatic hernia (CDH). The authors reviewed a single institution experience and challenged conventional wisdom in the context of a care strategy based on permissive hypercapnea/spontaneous respiration/elective repair.

METHODS

From August 1992 through February 2000, all infants with CDH and (1) respiratory distress requiring mechanical ventilation, (2) in-born or (3) transferred preoperatively within hours of birth are reported. All respiratory care strategy used permissive hypercapnea/spontaneous respiration and combined with elective repair. Arterial blood gas values and concomitant ventilator support were recorded. Outcome markers were (1) need for extracorporeal membrane oxygenation ECMO, (2) discharge to home, (3) supplemental oxygen need at discharge, and (4) influence of non-ECMO ancillary therapies (surfactant, nitric oxide, high-frequency oscillatory ventilation).

RESULTS

One hundred twenty consecutive infants were reviewed. Overall survival rate was 75.8%, but, excluding 18 of 120 not treated (6 lethal anomalies, 10 overwhelming pulmonary hypoplasia, 3 prerepair ECMO-related neurocomplications), 84.4% survived to discharge. A total of 67/120 were inborn. Non-ECMO ancillary treatments had no impact on survival rate. ECMO was used in 13.3%. Surgery was transabdominal; prosthetics were used in 7%. Tube thoracostomy was rare. Every inborn patient (n = 11) requiring a chest tube for pneumothorax died. Respiratory support before surgery was peak inspiratory pressure (PIP), 22, FIO(2),.43 with PaO(2), 66 torr; PaCO(2), 41 torr; and pH, 7.32. The survivors discharged on oxygen (n = 2) died at 4 and 7 months.

CONCLUSIONS

The majority of infants with life-threatening CDH treated with permissive hypercapnea/spontaneous respiration/elective surgery survive to discharge with minimal pulmonary morbidity.

Coordinated genetic control of neoplastic and nonneoplastic diseases in mice

Some models of aging imply that late-life diseases, though roughly synchronous, are the result of distinct pathophysiological processes, each in turn influenced by polymorphisms at multiple loci. Other models suggest that the dramatic increase in later life of multiple forms of illness might reflect the outcome of a unitary process, of so-far unknown biochemical nature, that proceeds at a species-specific rate to increase the risk of many forms of disease and disability in parallel. We have previously reported the results of genetic linkage analyses documenting the ability of alleles at D9Mit110, D10Mit15, and D12Mit167, and an allele pair at D2Mit58 and D16Mit182 to predict longevity in mice bred as the progeny of (BALB/cJ x C57BL/6J)F1 mothers and (C3H/HeJ x DBA/2J)F1 fathers (the UM-HET3 stock). Here we report the results of post hoc analyses to test the hypothesis that the genes that extend the life span of mice dying of neoplastic diseases also extend the life span of mice that die of nonneoplastic causes. In all four cases we find that the genotype associated with increased survival in mice dying of cancer is also associated for a similar degree of life span extension in mice dying of other causes. For D9Mit110 and the combination of D2Mit58 and D16Mit182, the difference is statistically significant in both the neoplastic and nonneoplastic mouse groups. The data support the hypothesis that many forms of late-life disease may be influenced by shared pathophysiologic mechanisms that are under coordinated genetic control.

Results of unrelated umbilical cord blood hematopoietic stem cell transplant

The number of umbilical cord blood transplants (UCBT) is increasing worldwide, and the purpose of Eurocord is to evaluate the results and compare the outcome of UCBT with allogeneic bone marrow transplants (BMT). Data have been reported to Eurocord by many transplant centers. Close links have been established with cord blood banks through Netcord. BMT data have been provided by transplant centers and also by the European Blood and Marrow Transplant (EBMT) and International Bone Marrow Transplant Registries (IBMTR). Eurocord has analyzed the outcome of unrelated UCBT from 121 transplant centers and 29 countries. The results have shown that survival with unrelated mismatched UCBT was comparable to that with unrelated BMT. Engraftment with cord blood was delayed, resulting in an increased incidence of early transplant complications. The incidence of acute and chronic graft-versus-host-disease (GVHD) was reduced with cord blood grafts even in HLA mismatched transplants and in adults. In patients with leukemia, the rate of relapse was similar to that after BMT. The overall event-free survival with UCBT was not statistically different when compared to BMT. In conclusion, this large registry study confirms the potential benefit of using umbilical cord blood hematopoietic stem cells for allogeneic transplants.

Allogeneic transplantation of G-CSF mobilized peripheral blood stem cells from unrelated donors: a retrospective analysis

BACKGROUND AND OBJECTIVES

Allogeneic peripheral blood stem cell transplantation (PBSCT) from matched siblings has lead to clinical results comparable to those of standard bone marrow transplantation (BMT). We report the outcome of 79 patients transplanted with PBSC from unrelated donors.

DESIGN AND METHODS

In 61 cases PBSC were used for primary transplantation whereas 18 patients were treated for relapse or graft-failure. In 35 patients receiving primary transplants, T-cell depletion (TCD) using CD34 positive selection of PBSC with or without additional T-cell depletion had been performed to reduce the risk of graft-versus-host-disease (GvHD).

RESULTS

The rate of primary graft-failure was higher (20%) in the TCD group than in that receiving unmanipulated grafts (UM) (5%, p=0.007). Patients with standard risk (n=34) receiving first transplants had a significantly better overall (60.4% vs. 24%, p=0.02) and disease-free survival (57.2% vs. 22.3%, p=0.006) compared to a high risk group of patients (n=21). There were no differences in the speed of neutrophil and platelet engraftment between TCD and UM transplants. As expected, the cumulative risk for acute GvHD grade II.-IV was significantly higher in the patients who had received UM grafts (71.8% vs. 38.1%, p=0.005). Although a trend towards a better survival rate was observed after TCD transplantation (52.2%) compared to the UM group (38.1%), this difference was not statistically significant. The probability of relapse was significantly higher in patients after UM transplants (38.8% vs. 8. 4%). This apparent paradox is explained by the higher number of high-risk patients in this group (p=0.03). Multivariable analysis of disease-free survival revealed risk category (p=0.02) and use of ATG (p=0.03) to be of significant impact. All patients (n=6) with non-malignant diseases are alive with full donor chimerism.

INTERPRETATION AND CONCLUSIONS

These data show that PBSC from unrelated donors can be transplanted either unmanipulated or CD34 selected. Prospective studies comparing BMT with PBSCT from unrelated donors are needed in defined disease categories.

Trends and patterns of mortality associated with birth defects and genetic diseases in the United States, 1979-1992: an analysis of multiple-cause mortality data

Contemporary information on the trends and patterns of mortality associated with birth defects and genetic diseases is lacking in the United States. To study these trends and patterns, we used the Multiple-Cause Mortality Files of the National Center for Health Statistics. From 1979 through 1992, 320,208 deaths in the United States were associated with birth defects and genetic diseases. The age-adjusted mortality rates for people with birth defects declined from about 8.2/100,000 in 1979 to about 6.7/100,000 in 1992, and the mortality rates for people with genetic diseases increased from 2.2/100,000 in 1979 to 2.5/100,000 in 1992. The mortality rate was higher among men than among women and higher among blacks than among whites or other races for both birth defect- and genetic disease-associated deaths. The rate among infants with birth defects was more than 25 times higher than that among other age groups. About half of the children whose deaths were associated with birth defects had cardiovascular system defects, 15% had central nervous system defects, and 12% had chromosomal defects. For deaths associated with genetic diseases, hereditary neurologic or storage disorders were the most common genetic diseases (38%), followed by metabolic disorders (21%), sickle cell and thalassemia (12%). The decline in the rate of mortality from birth defects in the United States probably reflects improvements in medical and surgical care and other factors. Most of the mortality associated with birth defects remains in the pediatric age group (less than 15 years old). The upward trend we detected for the deaths with genetic diseases was most likely related to improved recognition and reporting of some genetic diseases rather than to the increased prevalence.

Linked markers and age at diagnosis

This paper examines the relationship between age at diagnosis and markers linked to a disease trait using 100 replicates from Problem 2A in Genetic Analysis Workshop 10. After establishing the relationship between age and the quantitative trait used to define affection status, Q1, we evaluated the relationship between age at diagnosis and a marker which was linked with Q1. We found that the presence of an F allele at marker 15 on chromosome 5 was significantly associated with delayed age of diagnosis. When we evaluated 100 replicates, we found that the regression coefficients in the survival analyses were separated into two approximately normal distributions. The location of these distributions was solely reflective of the presence of affected individuals with the F allele in a particular replicate. In the replicates in one of the distributions, we found tremendous changes in the variance after employing survival models for dependent data. While we suggest that survival analysis of dependent data may be an important tool in investigating genotype specific alterations in age at event, the findings of this study indicate that the method used may be very sensitive to certain types of missing data.

Unrelated bone marrow transplantation in children: outcome and a comparison with sibling donor grafting

The clinical course of 59 children, who underwent BMT during 1988-1998 with a matched unrelated donor (MUD), was compared with 59 case controls receiving a sibling donor marrow. Thirty-eight patients had haematological malignancies while 21 had a nonmalignant disorder. The cumulative incidence of acute GVHD grade II-IV was 28% for MUD recipients vs 11% (P = 0.014) for sibling recipients. Extensive chronic GVHD was rare in both groups. The 5-year probability of survival was 52% for MUD vs 77% for sibling recipients (P= 0.014). For children with malignancies the 4-year probability of survival was 52% for MUD vs 67% for sibling recipients with a RFS of 49% vs 62%. In the ALL patients the survival of the MUD recipients was 77% and equalled that of the sibling group. For SAA survival was 43% vs 86% (P = 0.09) and for metabolic disorders 63% vs 89% (P = 0.025). The transplant-related mortality was higher in the MUD group, while death due to relapse was equally distributed. These results of MUD BMT in children compare favourably with most previous reports, and support the use of alternative donors in cases who lack an HLA-identical siblings. Bone Marrow Transplantation (2000).

Underwriting lethal genetic diseases

There are thousands of single gene deposits that cause increased morbidity or mortality risks. Few have complete penetrance leading to certain death. Most can be underwritten with affordable increases in premium; many at standard rates. As we learn more about penetrance for specific mutations we can learn to be more aggressive in underwriting inherited risks. I have described approaches to underwriting untested applicants to Huntington disease, and tested applicants who carry dominant mutations leading to breast, ovarian and colon cancer.

Contribution of birth defects and genetic diseases to pediatric hospitalizations. A population-based study

OBJECTIVE

To estimate the contribution of birth defects and genetic diseases to pediatric hospitalizations by use of population-based data.

DESIGN

Hospital discharges were categorized according to the diagnostic codes of The International Classification of Diseases, Ninth Revision, Clinical Modification. Hospitalizations that were related to birth defects and genetic diseases were compared with hospitalizations for other reasons, with respect to age, race/ethnicity, sex, length of stay, charges, source of payment, and mortality rate. Hospitalization rates and per capita charges were computed with the use of population estimates from 1990 census data.

MATERIALS

The 1991 population-based hospital discharge data from California and South Carolina.

RESULTS

Nearly 12% of pediatric hospitalizations in the 2 states combined were related to birth defects and genetic diseases. These children were, on average, about 3 years younger, stayed 3 days longer in a hospital, incurred 184% higher charges, and had a 4 1/2 times greater in-hospital mortality rate than children who were hospitalized for other reasons. The rate of hospitalizations that were related to birth defects and genetic diseases was 4 per 1000 children in both states, but these rates varied by age and race.

CONCLUSION

These population-based data are the first contemporary findings to show the substantial morbidity rate and hospitalization charges associated with birth defects and genetic diseases in the pediatric population.

IMPLICATIONS

This information is important for planning effective health care strategies, especially as the causes, treatments, and prevention of these disorders are being further elucidated by findings from human genome research and epidemiologic studies.

Actuarial considerations on genetic testing

In the UK the majority of life insurers employ relatively liberal underwriting standards so that people can easily gain access to life assurance cover. Up to 95% of applicants are accepted at standard terms. If genetic testing becomes widespread then the buying habits of the public may change. Proportionately more people with a predisposition to major types of disease may take life assurance cover while people with no predisposition may take proportionately less. A model is used to show the possible effect. However, the time-scales are long and the mortality of assured people is steadily improving. The change in buying habits may result in the rate of improvement slowing down. In the whole population, the improvement in mortality is likely to continue and could improve faster if widespread genetic testing results in earlier diagnosis and treatment. Life insurers would not call for genetic tests and need not see the results of previous tests except for very large sums assured. In the UK, life insurers are unlikely to change their underwriting standards, and are extremely unlikely to bring in basic premium rating systems that give discounts on the premium or penalty points according to peoples genetic profile. The implications of widespread genetic testing on medical insurance and some health insurance covers may be more extreme.

Estimated cost of person-Sv exposure

The present paper summarizes work performed under contract to the Department of Energy and reported separately. This paper covers efforts to define a cost per person-Sv by determining a value for a societal life and coupling the result with the probability of death due to radiation exposure. The value of a societal life was estimated by examining wrongful death awards and settlements, amounts taken out in life insurance, amounts spent in the last year of life for the critically ill, lifetime earnings and investments, and other approaches and values found in related literature. The values of a societal life ranged from $600,000 to $7,000,000, with a value of $4,000,000 considered by the authors as a conservative average in terms of 1990 U.S. dollars. The associated costs per person-Sv thus determined were found to range from $18,000 per person-Sv to $630,000 per person-Sv ($180 per person-rem to $6,300 per person-rem), with a value of $200,000 per person-Sv ($2,000 per person-rem) taken as a conservative average.

Localization of the gene (or genes) for a syndrome with X-linked mental retardation, ataxia, weakness, hearing impairment, loss of vision and a fatal course in early childhood

Linkage analysis is described in a family with X-linked mental retardation, ataxia, weakness, floppiness, delayed motor development, absence of deep tendon reflexes, hearing impairment and loss of vision (MIM no. 301835). The disease has a fatal course due to the susceptibility of the patients to infections, especially of the respiratory tract. Clinical signs indicate impairment of the posterior columns, peripheral motor and sensory neurons and the second and eighth cranial nerves and/or their nuclei. The involvement of the posterior columns of the spinal cord is further suggested by the almost complete absence of myelinated fibers therein. We localized the responsible gene(s) to Xq21.33-q24 between DXS1231 and DXS1001 with a maximum lod score of 6.97. The proteolipid protein gene, which codes for two myelin proteins of the central nervous system and is located in this region, was considered as a candidate gene for this disorder. However, no mutations were found in the protein-coding part of this gene.

Successful transplantation of HLA-matched and HLA-mismatched umbilical cord blood from unrelated donors: analysis of engraftment and acute graft-versus-host disease

To reduce the morbidity and mortality associated with unrelated donor bone marrow (BM) transplantation and potentially extend the pool of suitable donors, cryopreserved unrelated donor umbilical cord blood was considered as an alternate source of hematopoietic stem cells for transplantation. Patients with leukemia, BM failure syndrome, or inborn error of metabolism were eligible for a phase I clinical trial designed to estimate the risk of graft failure and severe acute graft-versus-host disease after transplantation of umbilical cord blood from unrelated donors. As of December 21, 1995, unrelated donor umbilical cord blood was used to reconstitute hematopoiesis in eighteen patients aged 0.1 to 21.3 years weighing 3.3 to 78.8 kg with acquired or congenital lympho-hematopoietic disorders or metabolic disease. Patients received either HLA-matched (n = 7) or HLA-1 to 3 antigen disparate (n = 11) grafts collected and evaluated by the New York Blood Center (New York, NY). The probability of engraftment after unrelated donor umbilical cord blood transplantation was 100% with no patient having late graft failure to date. The probability of grade III-IV acute graft-versus-host disease at 100 days was 11%. With a median follow-up of 6 months (range, 1.6 to 17 months); the probability of survival at 6 months is 65% in this high risk patient population. We conclude that cryopreserved umbilical cord blood from HLA-matched and mismatched unrelated donors is a sufficient source of transplantable hematopoietic stem cells with high probability of donor derived engraftment and low risk of refractory severe acute graft-versus-host disease. Limitations with regard to recipient size and degree of donor HLA disparity remain to be determined.

Contribution of heritable disorders to mortality in the pediatric intensive care unit

OBJECTIVES

To determine the percentage of patients dying in the pediatric intensive care unit (PICU) who have heritable disorders and to compare vital statistics classification of underlying cause of death with underlying heritable disorder identified from medical record review.

DESIGN

Retrospective medical record review.

SETTING

The PICU of a university-affiliated hospital.

METHODS

Medical records were reviewed for all deaths occurring in the PICA over a 5-year period. Further review, including hospital course, clinical findings, and the presence or absence of a genetic evaluation, was accomplished for those patients found to have a chromosome abnormality, recognized syndrome, single major malformation, or unrecognized syndrome. Underlying cause of death classification obtained from the Center for Health Statistics, Arkansas Department of Health was reviewed to determine the frequency with which the underlying heritable disorder was recorded.

RESULTS

Fifty-one of 268 (19%) deaths during the study period were in patients with heritable disorders. Of these 51 patients, eight (16%) had chromosome abnormalities, 17 (33%) had a recognized syndrome, 15 (29%) had a single primary defect in development, and 11 (22%) had an unrecognized syndrome. Genetic evaluation was carried out on 45% of patients, with the frequency of evaluation differing between categories of patients with heritable conditions. When underlying cause of death from vital statistics classification was reviewed, 21 of 51 (41%) records did not include the underlying heritable disorder.

CONCLUSIONS

Heritable disorders are a frequent cause of mortality in the PICU. Vital statistics classification of underlying cause of death in this population often fails to identify heritable disorders, leading to an underascertainment of these conditions in mortality statistics. Improved cause of death classification procedures will be necessary to target public health interventions to etiology-specific populations.

Hereditary antithrombin deficiency: heterogeneity of the molecular basis and mortality in Dutch families

We studied the molecular basis and genetic heterogeneity of hereditary antithrombin (III) deficiency in nine Dutch families. Polymerase chain reaction (PCR) amplification and direct sequencing of all antithrombin gene exons and flanking intronic regions identified mutations in eight families. Given the opportunity to correlate the molecular basis with survival, we addressed the relevance of molecular defects to mortality in inherited antithrombin deficiency. The defects included single nucleotide deletions (7671 del G, 7768-69 del G) and insertions (5501 ins A, 2463 G-->TC) that lead to frameshifts, a single base substitution [5381 C-->T (129Arg-->stop)] leading to a premature termination codon, and single base substitutions resulting in amino acid substitutions [2652 A-->C (63Tyr-->Ser), 13380 T-->C (421Ile-->Thr), and 13407 G-->T (430Cys-->Phe)]. All affected individuals were heterozygous for the defects. Previously we found in Dutch families that antithrombin deficiency did not lead to higher mortality compared with the general population. In accordance with these findings, we observed no excess mortality in the nine families [Observed:Expected, 52:52.6; standardised mortality ratio (SMR) 1.0, 95% confidence interval (CI), 0.7-1.3]. Our findings confirmed a considerable genetic heterogeneity underlying antithrombin deficiency. We therefore concluded that the lack of excess mortality in these families is not caused by a Dutch mild defect. We suggest that the longevity is not affected by molecular defects in the antithrombin gene and hypothesize that differences in mortality or natural history between families most likely result from other (genetic) risk factors.

Use of sibling data to estimate family mortality effects in Guatemala

This paper examines the potential bias in estimates of child mortality determinants produced by the questionable assumption that sibling data are independent, and estimates the unmeasured familial effects shared among siblings. The parameter estimates yielded by the multivariate hazard model are very similar to those yielded by the standard hazard model. The standard errors of the parameter estimates, however, tend to be underestimated in conventional analyses. The contribution to child mortality from the familial factors seems modest net of household socioeconomic status, at least in this Guatemalan data set.

[Hereditary diseases and abnormalities as cause of death during the first 2 years of life among 7 groups of Oslo children. A comparison between Norwegian and Pakistani children]

Perinatal and infant death are important indicators of community health. We examined the rate of stillbirth and death before the age of two years among 36,700 children with Norwegian and 2,750 children with Pakistani background. There was no difference in the rate of stillbirth and death during the second year of life, but a 2.5-3 times higher death rate during the first year of life among the Pakistani children, compared with the Norwegian children. When deaths due to single gene disorders and congenital malformations were excluded, the death rate during the first year of life was similar in the two groups. The Pakistani children had an 18 times higher death rate from autosomal recessive disorders and a ten times higher death rate from malformations of the central nervous system. The difference in death rate between the two groups was probably due to the high rate of consanguinity among the Pakistani parents.

Three cases of congenital adrenal hypoplasia: a cause of salt-wasting and mortality in the neonatal period

Three infants with congenital adrenal hypoplasia are described. The two surviving infants were detected and successfully treated in the neonatal period due to a suggestive family history (Case 1) and antenatal maternal oestriol screening (Case 2). The modes of inheritance, diverse clinical presentation, associated conditions, diagnostic work-up and pathology of congenital adrenal hypoplasia in these three infants is discussed.

Mortality in hereditary antithrombin-III deficiency--1830 to 1989

To determine whether antithrombin-III (AT-III) deficiency leads to an excess mortality, we studied 171 individuals from ten families with a proven hereditary deficiency. 73 were classified as certainly deficient either by direct measurement of AT-III concentration or by mendelian inheritance patterns. 98 individuals had a high probability (0.5) of deficiency. The 64 deaths recorded did not exceed those expected for the general population adjusted for age, sex, and calendar period. We suggest that a policy of prophylactic anticoagulation for patients with AT-III deficiency cannot be recommended.