Health-care professionals’ responsibility to patients’ relatives in genetic medicine: a systematic review and synthesis of empirical research

PurposeThe extent of the responsibility of health-care professionals (HCPs) to ensure that patients’ relatives are told of their risk is unclear. Current international guidelines take confidentiality to the individual patient as the default position, but some suggest that disclosure could be default and genetic information could be conceptualized as familial.MethodsOur systematic review and synthesis of 17 studies explored the attitudes of HCPs, patients, and the public regarding the extent of HCPs’ responsibility to relatives with respect to disclosure.ResultsHealth-care professionals generally felt a responsibility to patients’ relatives but perceived a variety of reasons why it would be difficult to act on this responsibility. Public/patient views were more wide-ranging. Participants identified several competing and overlapping arguments for and against HCP disclosure: guidelines do not permit/mandate it, privacy, medical benefit, impact on family dynamics, quality of communication, and respecting autonomy.ConclusionWe argue that HCPs can sometimes share genetic information without breaching confidentiality and that they could factor into their considerations the potential harm to family dynamics of nondisclosure. However, we need more nuanced research about their responsibilities to relatives, particularly as genomic tests are used more frequently in clinical practice.     

Procedure to protect confidentiality of familial data in community genetics and genomic research

The collection of familial data is an essential step for community genetics programs or genetic research. Ethical issues concerning privacy and confidentiality present a major challenge in such programs. In order to keep familial data confidential, we have developed a family-based numerical coding procedure which allows the use of confidential data and the determination of familial relationships without risk of disclosure. This procedure is composed of two parts: the physical separation of identifying information and individual data; and the use of a code containing all the information required to build family trees. This procedure has been used in Eastern Quebec since 1995, mainly for screening, genetic counseling, research on familial dyslipidemias, public health intervention, and research projects on the genetics of complex traits, such as arterial hypertension and coronary artery disease.     

Regulating the communication of genetic risk information: the Italian legal approach to questions of confidentiality and disclosure

Battistuzzi L, Ciliberti R, Forzano F, De Stefano F. Regulating the communication of genetic risk information: the Italian legal approach to questions of confidentiality and disclosure. Communication of genetic risk is a complex process in which the rights of the individual and those of relatives may conflict with regard to the information revealed by DNA testing. If patients who participate in clinical genetic testing refuse to share their genetic information with at-risk relatives, healthcare professionals need to reach a proper ethical balance between the right of individual patients regarding the confidentiality of their genetic test result and the right of families to be informed about their genetic risk. Rules and legislation in most countries generally protect the confidentiality of medical information but allow limited disclosure of genetic test results without the patient's consent in specific cases when certain conditions are met. The aim of this article is to draw attention to how Italian policymakers have attempted to balance protection of autonomy and confidentiality, and protection of health by means of a hybrid instrument. Furthermore, we show that some of the requirements of that instrument depart from the most widely recognized standards for non-consensual disclosure of genetic risk information, while at the same time allowing an unusually high level of discretion to healthcare professionals involved in genetic counseling and testing.     

Genetic testing in dyslipidemia: A scientific statement from the National Lipid Association

The genetic basis for more than 2 dozen monogenic dyslipidemias has largely been defined. Genetic technologies, such as DNA sequencing, can detect both rare and common DNA variants underlying dyslipidemias, and these methods are increasingly available. Although patients with extreme abnormalities in low-density lipoprotein cholesterol, triglycerides, or high-density lipoprotein cholesterol may be considered for genetic testing, it is only in a minority of patients that the results will alter treatment or outcomes. Currently, there is potential clinical utility of genetic testing for familial hypercholesterolemia, familial chylomicronemia syndrome, sitosterolemia, lysosomal acid lipase deficiency, and a few other rare disorders, and this will increase the demand for reliable genetic diagnostic methods at lower cost. Clinical indications for genetic testing for most dyslipidemias are not clearly established and currently no guidelines exist. A shared decision-making model between the patient and the provider is essential as patient values and preferences play a very strong role. Potential benefits of genetic testing include providing a firm diagnosis in many cases, guiding optimal management and prevention strategies, advancing care strategies beyond currently available treatments, and contributing to overall scientific progress. Understanding the limitations and risks of genetic testing techniques is also important, as is careful interpretation of genetic test results to achieve the greatest benefit. Here we review laboratory methods, as well as technical, biological, clinical, and ethical implications and applications of genetic testing in dyslipidemias.     

Clinical and genetic issues in dilated cardiomyopathy: A review for genetics professionals

Dilated cardiomyopathy (DCM), usually diagnosed as idiopathic dilated cardiomyopathy (IDC), has been shown to have a familial basis in 20–35% of cases. Genetic studies in familial dilated cardiomyopathy (FDC) have shown dramatic locus heterogeneity with mutations identified in >30 mostly autosomal genes showing primarily dominant transmission. Most mutations are private missense, nonsense or short insertion/deletions. Marked allelic heterogeneity is the rule. Although to date most DCM genetics fits into a Mendelian rare variant disease paradigm, this paradigm may be incomplete with only 30–35% of FDC genetic cause identified. Despite this incomplete knowledge, we predict that DCM genetics will become increasingly relevant for genetics and cardiovascular professionals. This is because DCM causes heart failure, a national epidemic, with considerable morbidity and mortality. The fact that early, even pre-symptomatic intervention can prevent or ameliorate DCM, coupled with more cost-effective genetic testing, will drive further progress in the field. Ongoing questions include: whether sporadic (IDC) disease has a genetic basis, and if so, how it differs from familial disease; which gene-specific or genetic pathways are most relevant; and whether other genetic mechanisms (e.g., DNA structural variants, epigenetics, mitochondrial mutations and others) are operative in DCM. We suggest that such new knowledge will lead to novel approaches to the prevention and treatment of DCM.     

Mole maker phenotype: possible narrowing of the candidate region

Recent data has suggested that familial recurrent hydatidiform mole is a rare autosomal recessive trait in women experiencing this gestational disease (MIM 231090). Here we provide molecular data on an additional family confirming that recurrent familial hydatidiform moles are diploid, biparental and arise from independent conceptions. A narrowing of the gene interval on chromosome 19q13.3-13.4 is suggested by haplotype analysis in two sisters.     

Process and outcome in communication of genetic information within families: a systematic review

The communication of risk is a central activity in clinical genetics, with genetic health professionals encouraging the dissemination of relevant information by individuals to their at-risk family members. To understand the process by which communication occurs as well as its outcomes, a systematic review of actual communication in families about genetic risk was conducted. Findings from 29 papers meeting the inclusion criteria were summarised and are presented narratively. Family communication about genetic risk is described as a deliberative process, in which: sense is made of personal risk; the vulnerability and receptivity of the family member is assessed; decisions are made about what will be conveyed; and the right time to disclose is selected. The communication strategy adopted will depend on these factors and varies within families as well as between families. Inherent in these processes are conflicting senses of responsibility: to provide potentially valuable information and to prevent harm that may arise from this knowledge. However, the research 'outcomes' of communication have been professionally determined (number of relatives reported as informed, uptake of testing, knowledge of the recipient) and are typically unrelated to the concerns of the family member. The impact of communication on the individual, family members, and family relationships is of concern to the individual conveying the information, but this is largely self-reported. Currently, there is insufficient information to inform the development of theoretically and empirically based practice to foster 'good' communication. The implications for future research are discussed.     

Transmissible and non-transmissible neurodegenerative disease: similarities in age of onset and genetics in relation to aetiology

In only a few cases is transmissible dementia known to have been acquired by infection from a source outside the individual; the remaining cases can be classified as sporadic, loosely familial, or autosomal dominant. Each group has a characteristic mean age of onset. A range of neurodegenerative diseases (including Alzheimer-type dementia and amyotrophic lateral sclerosis) can also be classified in this way, with similar characteristic mean ages of onset. The emergence of these diseases in later middle age, and the interdependence of age of onset and the type of familial occurrence suggest that these pathological processes are related to those genetic mechanisms which determine senescence. It is argued that the majority of cases of transmissible dementia arise, not from infection, but from the expression of endogenous virogene sequences as part of the aging processes.     

Personality dimensions harm avoidance and self-directedness predict the cortisol awakening response in military men

To account for individual differences in vulnerability for stress-related disorders, studies have examined the relationship between hypothalamic-pituitary-adrenal (HPA) axis functioning and personality. The present study examined the relationship between the free fraction of cortisol in saliva after awakening and personality as measured with Cloninger's Temperament and Character Inventory [Cloninger, C.R., Przybeck, T.R., Svrakic, D.M., Wetzel, R.D., 1994. The Temperament and Character Inventory (TCI): A Guide to its Development and Use. Washington University, Center for Psychobiology of Personality, St. Louis, MO] in 107 healthy male soldiers. Harm avoidance explained 9% of variance in cortisol levels after awakening (AUCG), and harm avoidance and self-directedness predicted 10% of variance in mean cortisol increase. The cortisol awakening response (CAR) was lower in participants with low scores on harm avoidance, and mean cortisol increase after awakening was higher in soldiers high on self-directedness and harm avoidance. These results show that the CAR is related to personality and that it can be used to examine individual differences in HPA (re)activity.     

Germline BRCA1 promoter deletions in UK and Australian familial breast cancer patients: Identification of a novel deletion consistent with BRCA1:psiBRCA1 recombination

Inherited susceptibility to breast cancer results from germline mutations in one of a number of genes including BRCA1. A significant number of BRCA1-linked familial breast cancer patients, however, have no detectable BRCA1 mutation. This could be due in part to the inability of commonly used mutation-detection techniques to identify mutations outside the BRCA1 coding region. This paper addresses the hypothesis that non-coding region mutations, specifically in the BRCA1 promoter, account for some of these cases. We describe a new and detailed restriction map of the 5' region of the BRCA1 gene including the nearby NBR2, psiBRCA1, and NBR1 genes and the isolation of a number of new informative hybridization probes suitable for Southern analysis. Using this information we screened DNA from lymphoblastoid cell-lines made from 114 UK familial breast cancer patients and detected one large deletion in the 5' region of BRCA1. We show that the breakpoints for this deletion are in BRCA1 intron 2 and between NBR2 and exon 2 of psiBRCA1, raising the possibility that this deletion arose via a novel mechanism involving BRCA1:psiBRCA1 recombination. We have also screened 60 familial breast cancer patients from the Australian population, using an amplification refractory mutation system (ARMS) technique described previously by our group, and found one patient with a genotype consistent with a BRCA1 promoter deletion. These findings indicate that germline BRCA1 promoter deletions are a rare and yet significant mutation event and that they could arise via a novel genetic mechanism.     

Genetic insights into familial tumors of the nervous system

Nervous system tumors represent unique neoplasms that arise within the central and peripheral nervous system. While the vast majority of nervous system neoplasm occur sporadically, most of the adult and pediatric forms have a hereditary equivalent. In a little over a decade, we have seen a tremendous increase in knowledge of the primary genetic basis of many of the familial cancer syndromes that involve the nervous system, syndromes that are mostly inherited as autosomal dominant traits. In this review, we discuss the most recent findings on the genetic basis of hereditary nervous system tumors. The identification of genes associated with familial cancer syndromes has in some families enabled a "molecular diagnosis" that complements clinical assessment and allows directed cancer surveillance for those individuals determined to be at-risk for disease.     

Combined tumor genomic profiling and exome sequencing in a breast cancer family implicates ATM in tumorigenesis: A proof of principle study

Familial breast cancers (BCs) account for 10%‐20% of all diagnosed BCs, yet only 20% of such tumors arise in the context of a germline mutation in known tumor suppressor genes such as BRCA1 or BRCA2. The vast genetic heterogeneity which characterizes non BRCA1 and non BRCA2 (or BRCAx) families makes grouped studies impossible to perform. Next generation sequencing techniques, however, allow individual families to be studied to identify rare and or private mutations but the high number of genetic variants identified need to be sorted using pathogenicity or recurrence criteria. An additional sorting criterion may be represented by the identification of candidate regions defined by tumor genomic rearrangements. Indeed, comparative genomic hybridization (CGH) using single nucleotide polymorphism (SNP) arrays allows the detection of conserved ancestral haplotypes within recurrent regions of loss of heterozygosity, common to several familial tumors, which can highlight genomic loci harboring a germline mutation in cancer predisposition genes. The combination of both exome sequencing and SNP array‐CGH for a series of familial BC revealed a germline ATM mutation associated with a loss of the wild‐type allele in two BC from a BRCAx family. The analysis of additional breast tumors from ten BC families in which a germline ATM mutation had been identified revealed a high frequency of wild‐type allele loss. This result argues strongly in favor of the involvement of ATM in these tumors as a tumor suppressor gene and confirms that germline ATM mutations are involved in a subset of familial BC.     

Hepatosteatosis with hypobetalipoproteinemia

Nonalcoholic fatty liver disease is increasingly recognized as a condition that may progress to chronic liver disease. Most cases of fatty liver are asymptomatic and often are detected during routine medical or laboratory examinations. There also are some rare genetic diseases such as abetalipoproteinemia and familial hypobetalipoproteinemia that may cause fatty liver disease. Both are inherited disorders of lipoprotein metabolism. Although abetalipoproteinemia and homozygous familial hypobetalipoproteinemia patients present with severe manifestations, heterozygotes are usually asymptomatic. In the last several years, case reports or studies indicating a relationship between hepatosteatosis and familial heterozygote hypobetalipoproteinemia (FHBL) have been reported. Here, we report three cases of FHBL with characteristic lipid profile, mildly elevated liver enzymes and hepatosteatosis confirmed by ultrasonography.     

How many cases of disease in a pedigree imply familial disease?

The ability to perform whole‐exome and, increasingly, whole‐genome sequencing on large numbers of individuals has led to increased efforts to identify rare genetic variants that affect the risk of both common and rare diseases. In such applications, it is important to identify families that are segregating the rare variants of interest. For rare diseases or rare familial forms of common diseases, pedigrees with multiple affected members are clearly harbouring risk variants. For more common diseases, however, it may be unclear whether a family with a few affected members is segregating a familial disease, is the result of multiple sporadic cases, or is a mixture of familial cases and phenocopies. We provide calculations for the probability that a family is harbouring familial disease, presented in general terms that admit working guidelines for selecting families for current sequencing studies. Using examples motivated by our own studies of thyroid cancer and published studies of colorectal cancer, we show that for common diseases, families with exactly two affected first‐degree relatives have only a moderate probability of segregating familial disease, but this probability is higher for families with three or more affected relatives, and those families should therefore be prioritised in sequencing studies.     

Experiences and attitudes of genome investigators regarding return of individual genetic test results

PurposeWhether and how to return individual genetic results to study participants is among the most contentious policy issues in contemporary genomic research.MethodsWe surveyed corresponding authors of genome-wide association studies, identified through the National Human Genome Research Institute’s Catalog of Published Genome-Wide Association Studies, to describe the experiences and attitudes of these stakeholders.ResultsOf 357 corresponding authors, 200 (56%) responded. One hundred twenty-six (63%) had been responsible for primary data and sample collection, whereas 74 (37%) had performed secondary analyses. Only 7 (4%) had returned individual results within their index genome-wide association studies. Most (69%) believed that return of results to individual participants was warranted under at least some circumstances. Most respondents identified a desire to benefit participants’ health (63%) and respect for participants’ desire for information (57%) as major motivations for returning results. Most also identified uncertain clinical utility (76%), the possibility that participants will misunderstand results (74%), the potential for emotional harm (61%), the need to ensure access to trained clinicians (59%), and the potential for loss of confidentiality (51%) as major barriers to return of results.ConclusionInvestigators have limited experience returning individual results from genome-scale research, yet most are motivated to do so in at least some circumstances.     

Establishment of a method of anonymization of DNA samples in genetic research

As the number of the genetic studies has rapidly increased in recent years, there has been growing concern that the privacy of the participants in such studies can be invaded unless effective measures are adopted to protect confidentiality. It is crucial for the scientific community to establish a method to anonymize DNA samples so that the public will trust genetic researchers. Here, we present a reliable and practical method of making DNA samples used in the genetic research anonymous. It assures complete anonymity by coding samples and personal information twice. Since it does not require equipment, such as bar-code readers or a software package, its cost is nominal compared with the laboratory costs. All institutions engaged in genetic research may wish to take measures such as the one described here to ensure the privacy and confidentiality of the participants in their genetic studies. K. Hara and K. Ohe contributed equally to this work     

Difficulties of genetic counseling and prenatal diagnosis in a consanguineous couple segregating for the same translocation (14;15) (q11;q13) and at risk for Prader-Willi and Angelman syndromes

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are associated with a loss of function of imprinted genes in the 15q11-q13 region mostly due to deletions or uniparental disomies (UPD). These anomalies usually occur de novo with a very low recurrence risk. However, in rare cases, familial translocations are observed, giving rise to a high recurrence risk. We report on the difficulties of genetic counseling and prenatal diagnosis in a family segregating for a translocation (14;15)(q11;q13) where two consanguineous parents carry the same familial translocation in this chromosome 15 imprinting region. Both children of the couple inherited a chromosomal anomaly leading to PWS. However, a paternal 15q11-q13 deletion was responsible for PWS in the first child, whereas prenatal diagnosis demonstrated that PWS was associated with a maternal 15q11-q13 UPD in the fetus. This report demonstrates that both conventional and molecular cytogenetic parental analyses have to be performed when a deletion is responsible for PWS or AS in order not to overlook a familial translocation and to insure reliable diagnosis and genetic counseling.     

Familial hepatocellular carcinoma in an endemic area of Thailand

Hepatocellular carcinoma (HCC), while rare in the United States and other western countries, represents a major cause of death in certain areas of the world, including southeast Asia. While the etiology of HCC remains enigmatic, it is of interest that hepatitis-B viral infection (HBV) has occurred in significant excess in those geographic regions endemic for HCC. Only limited attention has been given to the role of primary genetic factors in HCC, but scattered anecdotal reports have identified familial aggregations of this disease. We report a family in which histologically verified HCC was found in a mother and two of her four sons, all of whom were concordant for HBV infection. We also briefly discuss two additional familial aggregations of HCC from Costa Rica. We propose that greater attention to be given to the role of primary genetic factors in HCC and that appropriate consideration be given to interaction with other environmental factors, such as aflatoxin exposures, nitrosamines, and HBV infection. While our observations document familial clustering of HCC with concordance for HBV, we caution that support of a genetic hypothesis will require more extensive investigation.     

Confidentiality and informed consent and the acquired immunodeficiency syndrome epidemic

The acquired immunodeficiency syndrome epidemic has led to significant medicolegal concerns in the areas of informed consent and confidentiality. These legal concepts are directed at preserving respect for individual autonomy and privacy in the face of the epidemic. Emerging legal doctrines and issues related to consent and confidentiality are outlined, and areas where the laboratory may develop procedures and policies in light of the doctrines are suggested.     

Recent insights into the molecular pathogenesis of pheochromocytoma and paraganglioma

Pheochromocytomas and paragangliomas are rare tumors derived from chromaffin cells. These tumors can arise in the context of hereditary cancer syndromes such as von Hippel-Lindau disease, multiple endocrine neoplasia type 2, and neurofibromatosis 1. Recent studies indicate that germ line mutations of genes encoding specific succinate dehydrogenase (SDH) subunits also predispose individuals to pheochromocytomas and paragangliomas. This review focuses on the genetics of these tumors and suggests a possible link between familial pheochromocytomas/paraganglioma genes and control of neuronal apoptosis during embryological development.