Role of the geneticist in testing and counseling for inherited thrombophilia

Research progress of nephrotic syndrome accompanied by thromboembolism

Thromboembolism (TE) is a common and serious complication of nephrotic syndrome (NS). NS is associated with hypercoagulability, which may be induced by changes in coagulation, anticoagulant, and fibrinolytic factors. Moreover, accumulating evidence supports the hypothesis that the complex interactions between genetic and acquired risk factors in TE should be considered and that genetic susceptibility should not be ignored. Extracellular vesicles (EVs) also play unique roles. Further research on EVs may provide new insights into the discovery and treatment of TE associated with NS. The occurrence of NS accompanied by TE may be associated with various risk factors. Preventive anticoagulant therapy can not only reduce the risk of TE in patients but also aggravate the risk of bleeding. Heparin and vitamin K antagonists (VKAs), traditional anticoagulant drugs, have been extensively applied in the prevention and treatment of thromboembolic diseases, and emerging direct oral anticoagulants (DOACs) also provide an alternative choice. Owing to the particularity of NS, the safe application of DOACs still needs to be addressed. This review aimed to comprehensively describe the pathophysiology of TE in NS, as well as analyze the associated risk factors, the opportunity for preventive anticoagulation, and current anticoagulant information.

Education Case: Hereditary Thrombophilia With Double Heterozygous Factor V Leiden and Factor II c.*97G>A Mutations

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.¹.

Inherited Risk Factors of Thromboembolic Events in Patients with Primary Nephrotic Syndrome

Background and objectives. Venous thromboembolic events (VTEs) are among the most important complications of nephrotic syndrome (NS). We conducted a study that aimed to determine the prevalence of inherited risk factors for VTE in NS and to identify which factors are independent predictors of VTE. Materials and Methods. Thirty-six consecutive patients with primary NS that underwent percutaneous kidney biopsy between January 2017 and December 2017 were enrolled in this retrospective, observational study. VTEs were the primary outcome. Baseline demographic and biochemical data were collected from medical records, and genetic testing was done for polymorphisms of Factor V, PAI, MTHFR, and prothrombin genes. Results. The incidence of VTE was 28%, and the median time to event was 3 months (IQR: 2-9). The prevalence of inherited risk factors was 14% for Factor V Leiden mutation, 5.6% for prothrombin G20210A, 44.5% for PAI, and 27.8% for each of the two polymorphisms of the MTHFR gene. On multivariate analysis, the presence of at least two mutations was independently associated with the risk of VTE (HR, 8.92; 95% confidence interval, CI: 1.001 to 79.58, p = 0,05). Conclusions. These findings suggest that genetic testing for inherited thrombophilia in NS could play an important role in detecting high-risk patients that warrant prophylactic anticoagulation.

Hemostasis-related gene polymorphisms and their epistatic relationship in women with idiopathic infertility

: A numerous factor can cause infertility, but around one of four reproductive failure cases remain unexplained and diagnosed as idiopathic infertility. In the past few decades, analysis of gene polymorphisms takes a significant place in pathogenesis of infertility. The aim of this study was to evaluate the possible role of hemostasis-related gene polymorphisms in unexplained infertility. The study includes 117 female patients with idiopathic infertility and 130 fertile women with at least one born child. Eight polymorphisms important for hemostasis (ITGB3 1565T>C, FV 1691G>A, FII 20210G>A, MTHFR 677C>T and 1298A>C, ATIII 786G>A, PAI-14G/5G and ACE I/D) were genotyped by real-time PCR system. The frequencies of alleles and genotypes of examined polymorphisms were analyzed in SPSS statistical program, whereas gene interactions were identified using the GMDR software. Examination of etiological factors has shown that family history is a significant factor in assessing individual risk for infertility. The alleles and genotypes frequency of FV 1691G>A and FII 20210G>A polymorphisms were statistically different between control and patient group leading to a greater risk for infertility. The analysis of epistatic relationship between examined hemostasis-related gene polymorphisms identified more complex high-risk genotypes associated with infertility. Our results suggest that positive family history could be important predictive factor for fertility problems, pointing to the potential hereditary basis of this condition. Polymorphisms FVL and FII prothrombin are independent risk factors for idiopathic infertility, whereas multilocus interactions approach should be taken into consideration for the future research.

Hereditary thrombophilia in trauma patients with venous thromboembolism: Is routine screening necessary?

BACKGROUND

Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), remains a common complication following trauma. The role of hereditary thrombophilia (HT) in posttraumatic VTE is unknown. In the general population with a first-time DVT, Factor V Leiden (FVL) and prothrombin G20210A mutation (PGM) are the most common types of HT with an incidence of 20% to 25% and 6% to 18%, respectively. The objective of this study was to identify the incidence of FVL and PGM in posttraumatic VTE to determine whether routine screening for HT in trauma should be performed.

METHODS

We conducted a prospective observational study at our Level I trauma center from 2013 to 2016 when 70 patients with posttraumatic DVT and PE were screened for FVL and PGM. Demographics, injury characteristics, and established risk factors for VTE were collected for each patient. Statistical analysis was performed to compare patients with and without HT.

RESULTS

The incidence of FVL and PGM in posttraumatic VTE was 1.4% and 5.7%, respectively. All HT-positive patients had a DVT and one had an associated PE. Both the individual risk factors and the total number of risk factors for VTE were similar between the HT-positive group and the HT-negative group.

CONCLUSION

There was a lower incidence of FVL and PGM in patients with posttraumatic DVT than in patients with a first-time DVT in the general population. HT does not appear to significantly contribute to posttraumatic VTE in our trauma population. Further research is warranted to determine whether routine screening for HT in trauma should be performed.

LEVEL OF EVIDENCE

Epidemiological study, level III; Care management/therapeutic study, level IV.

Amniotic fluid embolism and spontaneous hepatic rupture during uncomplicated pregnancy: a case report and literature review

Amniotic fluid embolism (AFE) and spontaneous hepatic rupture both are extremely rare complications of pregnancy that can be fatal to mother and/or child. AFE is characterized by a sudden collapse of the cardiovascular system, a change in mental status, and disseminated intravascular coagulation (DIC), occurring immediately during labor, delivery, or postpartum, caused by the inflow of amniotic components into the maternal circulation. Spontaneous hepatic rupture during pregnancy which is most often occurs alongside hypertensive disorders, eclampsia, or HELLP syndrome. We report on the case of a 28-year-old woman (G3P2) who is suffering from AFE and spontaneous hepatic rupture, without history of hypertensive disorders, preeclampsia/eclampsia, or HELLP syndrome, and she died suddenly after delivering of a severe asphyxial neonate within 1 h with postpartum of hepatic rupture and massive hemorrhage. The lack of typical clinical signs and symptoms resulted to the difficulty of early diagnosis. If AFE and hepatic rupture is highly suspected in a pregnant patient, a collaborative multidisciplinary approach is mandatory. Pregnancy women is simultaneously complicated in amniotic fluid embolism and spontaneous hepatic rupture, similar cases are infrequent in the literature, which is reviewed in this report, explore the pathophysiological changes, we hope that can be helpful for the prevention, diagnosis and treatment of similar cases.

Cerebral Thrombosis: A Neurogenetic Approach

Cerebral venous thrombosis (CVT) is a severe multifactorial condition with various clinical manifestations that may include headache, papilledema, seizures, focal deficits, coma and death. The mortality rate of untreated CVT is up to 50%, but it drops to 10% when CVT is properly treated. Prevention of CVT is feasible through healthy lifestyle, genetic counseling, molecular genetic analysis for common thrombophilia-related mutations, and prophylactic anticoagulative medication.

Hereditary and Acquired Thrombophilia in Splanchnic Vein Thrombosis: A Single-Center Experience

The purpose of this study was to characterize differences in the prevalence of hereditary and acquired thrombophilia in patients with splanchnic vein thrombosis (SVT). A total of 88 consecutive patients with SVT, including Budd Chiari Syndrome (n = 47) and portal extrahepatic portal vein obstruction (n = 41), underwent comprehensive thrombophilia testing, including testing for heritable and acquired causes. In 33 (37.5%) patients, etiology could be explained by at least 1 of the heritable etiologic factors, and 31 (35.2%) patients could be explained by at least 1 of the acquired causes studied. The combination of multiple concurrent factors was present in 9 (11.4%) patients. Among the heritable causes, the risk of SVT was found increased in the presence of thrombophilia resulting from the deficiencies of the naturally occurring anticoagulant proteins, and the acquired thrombogenic factors were significantly associated with causation of thrombosis in adult patients with SVT.

Health-related direct-to-consumer genetic tests: a public health assessment and analysis of practices related to Internet-based tests for risk of thrombosis

BACKGROUND

Recent years have seen increased concern about direct-to-consumer (DTC) genetic testing (i.e., the sale and use of genetic tests without involving a health care provider). Numerous professional organizations have developed policies in this area. However, little systematic evidence exists to inform public policy about these tests.

METHODS

We conducted a systematic search to identify genetic tests that are sold DTC without involving a health care provider. We evaluated the practices of companies offering DTC genetic tests for risk of thrombosis using criteria from multiple sources and a minimal set of key practices.

RESULTS

We identified 84 instances of currently available health-related DTC genetic tests sold on 27 Web sites; the most common were for pharmacogenomics (12), risk of thrombosis (10), and nutrigenomics (10). For the DTC genetic tests for risk of thrombosis, we found low adherence to recommendations. Online information was frequently incomplete and had low agreement with professional recommendations.

CONCLUSION

Our findings document the rapid growth in the availability of health-related DTC genetic tests and highlight the need to improve the delivery of DTC genetic tests. A major implication of this study is the need for the scientific and medical community to develop consistent recommendations to increase their impact.

Fatal postpartum spontaneous liver rupture: case report and literature review

Maternal hepatic rupture is a rare complication of pregnancy that can be fatal to both mother and child. This phenomenon is most often associated with preeclampsia/eclampsia and/or HELLP syndrome, which is defined by a collection of clinical features including hemolysis (H), elevated liver enzymes (EL), and a low platelet count (LP). These disease processes are typically identified and treated during pregnancy, often in the last trimester. The described case is unusual in that the decedent had no known history of preeclampsia/eclampsia or HELLP syndrome during this pregnancy, and she died suddenly several days postpartum of liver rupture with massive intraperitoneal hemorrhage following a routine cesarean section delivery and an uneventful hospital course. Similar cases are infrequent in the literature, which is reviewed in this report.

Thrombophilia screening in asymptomatic children

Children with a family history of thrombophilia and/or thrombosis are often referred to pediatric thrombosis centers for evaluation. This article reviews the risks and benefits of thrombophilia testing in this unique population. The article also reviews an approach to testing including a step-wise evaluation and involvement of a genetic counselor.

Inherited Thrombophilia: Key Points for Genetic Counseling

With the evolution of medical genetics to focus on highly prevalent, multifactorial conditions, it is inevitable that genetic counselors will be called upon to participate in the evaluation and counseling of individuals with inherited thrombophilia. The purpose of this review is to educate the genetic counselor on key issues related to risk assessment and genetic counseling for hereditary thrombophilia. The information contained in this document is derived from an extensive review of the literature, as well as the author's personal expertise. Upon completion of this review, the genetic counselor will be able to: a) describe inherited and acquired risk factors for thrombosis, b) collect and interpret personal and family histories to assess risk related to hereditary thrombophilia, c) discuss the potential advantages and disadvantages of thrombophilia testing, including psychosocial aspects and implications for medical management, and d) identify educational and support resources for patients and families.

Thrombophilia and Women's Health: An Overview

Thrombophilia, whether inherited or acquired, is one of the hot topics in women's health. Several factors, some of which are specific to the female patient, enhance thrombus formation in the presence of thrombophilia and include oral contraception, hormone replacement therapy, pregnancy, and puerperium. Thrombotic events are not only restricted to venous thromboembolism but also are believed to cause repeated embryonic loss, fetal loss, placental abruption, intrauterine growth restriction, and severe pre-eclampsia. It seems that some thrombophilias, and a combination of thrombophilic factors, carry a greater risk than others for a given adverse outcome. The addition of LMWH to the armamentarium was associated with conceptual change in the practice of anticoagulation. Care should be exercised in the interpretation of various risks and the potential of anticoagulation as a remedy to reduce that risk.

Family history is a poor screen for prothrombotic genes in children with stroke

OBJECTIVE

To evaluate family history of early pathological thrombosis as a screen for genetic prothrombotic risk factors in children with stroke.

STUDY DESIGN

A 5-year retrospective review of standardized pediatric stroke clinic evaluations of children with arterial ischemic stroke (AIS) or sinovenous thrombosis (SVT). A family history of early pathological thrombosis was defined as stroke, heart attack, or deep venous thrombosis before 50 years of age or multiple miscarriages in the parents or grandparents of the patient. We evaluated the association between family history and the presence of the Factor V Leiden mutation (FVL) and/or Prothrombin G20210A mutation (PTG) in these children.

RESULTS

The study included 68 children. Thirteen (19.1%) had a positive family history of early pathological thrombosis, nine (13.2%) were heterozygous for FVL, and one (1.5%) was heterozygous for PTG. Family history was not associated with the presence of FVL (p = .36) or FVL combined with PTG (p = .40). For FVL, family history had a positive predictive value of 23.1% and a negative predictive value of 89.1%.

CONCLUSION

A family history of early thrombosis is not associated with the presence of FVL or PTG in children with stroke. We recommend that all children with stroke receive a prothrombotic workup regardless of family history.

Technical standards and guidelines: Venous thromboembolism (Factor V Leiden and prothrombin 20210G>A testing): A disease-specific supplement to the standards and guidelines for clinical genetics laboratories

These standards and guidelines are designed primarily as an educational resource for clinical laboratory geneticists to help them provide quality clinical laboratory genetic services. Adherence to this statement does not necessarily ensure a successful medical outcome. These standards and guidelines should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same results. In determining the propriety of any specific procedure or test, the clinical molecular geneticist should apply his or her own professional judgment to the specific clinical circumstances presented by the individual patient or specimen. It may be prudent, however, to document in the laboratory record the rationale for any significant deviation from these standards and guidelines.

Genetic Evaluation and Counseling of Couples with Recurrent Miscarriage: Recommendations of the National Society of Genetic Counselors

The objective of this document is to provide recommendations for genetic evaluation and counseling of couples with recurrent miscarriage (RM). The recommendations are the opinions of the multidisciplinary Inherited Pregnancy Loss Working Group (IPLWG), with expertise in genetic counseling, medical genetics, maternal fetal medicine, internal medicine, infectious disease, cytogenetics, and coagulation disorders. The IPLWG defines RM as three or more clinically recognized consecutive or non-consecutive pregnancy losses occurring prior to fetal viability (<24 weeks gestation). These recommendations are provided to assist genetic counselors and other health care providers in clinical decision-making, as well as to promote consistency of patient care, guide the allocation of medical resources, and increase awareness of the psychosocial and cultural issues experienced by couples with RM. The IPLWG was convened with support from the March of Dimes Western Washington State Chapter and the University of Washington Division of Medical Genetics. The recommendations are U.S. Preventive Task Force Class III, and are based on clinical experiences, review of pertinent English-language published articles, and reports of expert committees. This document reviews the suspected causes of RM, provides indications for genetic evaluation and testing, addresses psychosocial and cultural considerations, and provides professional and patient resources. These recommendations should not be construed as dictating an exclusive course of medical management, nor does the use of such recommendations guarantee a particular outcome. The professional judgment of a health care provider, familiar with the circumstances of a specific case, should always supersede these recommendations.

Thrombophilien bei Patienten mit isch�mischem Schlaganfall

Patients with ischemic stroke are sometimes found to have an underlying inherited (deficiency of protein C, protein S, antithrombin III, activated protein C resistance, prothrombin gene mutation, hyperhomocysteinemia) or acquired thrombophilia (lupus anticoagulant and anticardiolipin antibodies, hyperhomocysteinemia). Patient selection for thrombophilia screening is, therefore, a frequent question in managing patients with ischemic stroke. In this review we discuss patient selection and timing for laboratory tests for thrombophilia screening in stroke patients based on a literature review and we calculated overall costs per year in Germany for testing patients older than 18 years with an ischemic stroke of undetermined cause. As there is a lack of studies comparing anticoagulation with antiplatelet therapy in patients with diagnosed thrombophilia, laboratory screening for thrombophilia even in a selected group of patients with cryptogenic ischemic stroke remains of questionable value at present. An exception appears to be testing for lupus anticoagulant and anticardiolipin antibodies in younger patients with suspected antiphospholipid syndrome (two positive test results necessary), because anticoagulation seems to be superior to aspirin in patients with antiphospholipid syndrome.

Ensuring the appropriate use of genetic tests

Ensuring the correct use of genetic tests is an important challenge for health-policy makers. Many new genetic tests will identify susceptibility to common diseases or adverse drug responses. Some will lead to new prevention opportunities, but others will have minimal clinical value. Statutory regulation alone cannot guarantee appropriate use. Other strategies, including resource allocation and matters related to clinical governance - such as practice-guideline development and health-provider education - are also important.

Thrombosis during infancy and childhood: what we know and what we do not know

Despite underlying illnesses, children have a greater chance to survive and are expected to live 6 to 8 decades following an episode of venous or arterial thrombosis. The disproportionate benefits of preventing thrombosis and its sequelae in pediatric patients are evident. Therefore, it is necessary to develop appropriate strategies for diagnosis and management of thromboembolic events in children and to understand their acute and long-term effects. There still are many unanswered questions and clinical trials are being designed to help study these important issues.

Genetic thrombophilia

The genetic thrombophilias are an important cause of venous thrombotic events. Much has been learned about the natural history of these disorders, their genetics, and, to a lesser degree, their treatment. This article provides an overview of the genetics of thrombophilia. Specific information on the factor V Leiden mutation;the prothrombin G20210A mutation; and protein C, proteinS, and antithrombin deficiency is reviewed. Current testing and treatment options for the genetic thrombophilias also are discussed.

Platelet GP IIIa Polymorphism HPA-1 (PlA) Protects Against Subarachnoid Hemorrhage

Background and Purpose— Few genetic modifications have been identified to be associated with subarachnoid hemorrhage (SAH), most of them playing a role in the formation or size of aneurysms.

Methods— We evaluated the role of common and functional polymorphisms affecting the main platelet adhesive glycoproteins (GP) (GPIIIa: HPA-1; GPIa: HPA-5 and C807T; GPIbα: HPA-2 and VNTR) in the risk for development of the disease and in the severity of the onset. The study was performed in 103 patients with SAH, 103 matched controls, and 473 subjects from the general population.

Results— The HPA-1b (PlA2) allele significantly protected against SAH (OR, 0.48; 95% CI, 0.24 to 0.96; P =0.037). Interestingly, patients carrying this allele displayed larger aneurysms, but the extension of their hemorrhage and the clinical grade at presentation was significantly lower when compared with patients HPA-1 a/a (11.9±2.8 mm versus 8.8±2.2 mm, P =0.0001. Fisher grade ≤2: 68.4% versus 20%; P =0.0001; Hunt and Hess score <IV; 84.2% versus 53.8%; P =0.0187, respectively). The protection of the HPA-1b allele seemed to be exacerbated by the simultaneous presence of the HPA-2b allele. Thus, no patient carried this combination, which was present in 7.8% of controls ( P =0.007).

Conclusions— We present the first evidence suggesting a protective role for the platelet GPIIIa HPA-1b allele in SAH. The suggested platelet hyper-reactivity determined by this allele could reduce the risk to suffer SAH, specially if the aneurysm is small, attenuate the severity of the hemorrhage, and reduce the clinical grade at presentation. This effect might be amplified by the simultaneous combination with the GPIbα HPA-2b allele.

GENETIC TESTING IN PRIMARY CARE

Rapid advances in genetic research are leading to an expanding array of genetic tests. Primary care providers will increasingly be challenged to identify patients whose symptoms, physical findings, or family history indicate the need for genetic testing, and to determine how to use genetic information most effectively to improve disease prevention. In addressing these challenges, practitioners will need to consider the range of different uses of genetic testing, including diagnosis in symptomatic and asymptomatic people, risk assessment, reproductive decision-making, and population screening. They will need a set of core skills and knowledge to evaluate family history and to recognize clinical findings that indicate genetic risk. At the same time, the primary care perspective will contribute to the evaluation of appropriate uses of genetic testing. A partnership between medical genetics and primary care will help to ensure the development of effective policies, educational tools, and practice guidelines for the coming era of genomic health care.

Stroke in newborn infants

The few days before and after birth are a time of special risk for stroke in both mother and infant, probably related to activation of coagulation mechanisms in this critical period. Arterial ischaemic stroke around the time of birth is recognised in about one in 4000 full-term infants, and may present with neurological and systemic signs in the newborn. Neonatal seizures are most commonly the clinical finding that triggers assessment. In other children, perinatal stroke is recognised only retrospectively, with emerging hemiparesis or seizures after the early months of life. Risk factors for perinatal stroke include hereditary or acquired thrombophilias and environmental factors. Perinatal stroke underlies an important share of congenital hemiplegic cerebral palsy, and probably some spastic quadriplegic cerebral palsy and seizure disorders. There is much to be learned about the natural history of perinatal stroke, and there are as yet no evidence-based strategies for prevention or treatment.

Advances in preconception genetic counseling

Preconception counseling offers couples contemplating pregnancy the opportunity to identify and reduce potential pregnancy risks, plan care for known risks, and establish early prenatal care. The goal of preconception counseling is to promote physically and emotionally healthy parents in an attempt to ensure optimal prenatal, intrapartum, and postpartum maternal and fetal health. The advantages of addressing these issues prior to conception include the opportunity of giving recurrence or occurrence risk information for informed decision regarding pregnancy, the accessibility of more reproductive options such as preimplantation genetic diagnosis, and the opportunity to make lifestyle, medical, and behavior alterations for optimal maternal and fetal outcome. This article will discuss advances and updates in preconception genetic counseling including risk assessment and potential intervention for concerns identified through evaluation of family history, ethnicity, maternal age, medical and obstetric history, and associated psychosocial and nursing implications. Significant advances have emerged in the areas of cystic fibrosis carrier screening, first trimester screening, preimplantation genetic diagnosis, and detection and treatment of maternal thrombophilia.