Role Of Genetic Screening Research Articles

Physician-directed genetic screening to evaluate personal risk for medically actionable disorders: a large multi-center cohort study

BackgroundThe use of proactive genetic screening for disease prevention and early detection is not yet widespread. Professional practice guidelines from the American College of Medical Genetics and Genomics (ACMG) have encouraged reporting pathogenic variants that confer personal risk for actionable monogenic hereditary disorders, but only as secondary findings from exome or genome sequencing. The Centers for Disease Control and Prevention (CDC) recognizes the potential public health impact of three Tier 1 actionable disorders. Here, we report results of a large multi-center cohort study to determine the yield and potential value of screening healthy individuals for variants associated with a broad range of actionable monogenic disorders, outside the context of secondary findings.MethodsEligible adults were offered a proactive genetic screening test by health care providers in a variety of clinical settings. The screening panel based on next-generation sequencing contained up to 147 genes associated with monogenic disorders within cancer, cardiovascular, and other important clinical areas. Sequence and intragenic copy number variants classified as pathogenic, likely pathogenic, pathogenic (low penetrance), or increased risk allele were considered clinically significant and reported. Results were analyzed by clinical area and severity/burden of disease using chi-square tests without Yates’ correction.ResultsAmong 10,478 unrelated adults screened, 1619 (15.5%) had results indicating personal risk for an actionable monogenic disorder. In contrast, only 3.1 to 5.2% had clinically reportable variants in genes suggested by the ACMG version 2 secondary findings list to be examined during exome or genome sequencing, and 2% had reportable variants related to CDC Tier 1 conditions. Among patients, 649 (6.2%) were positive for a genotype associated with a disease of high severity/burden, including hereditary cancer syndromes, cardiovascular disorders, or malignant hyperthermia susceptibility.ConclusionsThis is one of the first real-world examples of specialists and primary care providers using genetic screening with a multi-gene panel to identify health risks in their patients. Nearly one in six individuals screened for variants associated with actionable monogenic disorders had clinically significant results. These findings provide a foundation for further studies to assess the role of genetic screening as part of regular medical care.

Role of Genetic Screening in the Management of Familial Focal Segmental Glomerulosclerosis: A Tale of Two Sisters.

Role of Genetic Screening in the Management of Familial Focal Segmental Glomerulosclerosis: A Tale of Two Sisters.

Familial Mediterranean fever without cardinal symptoms and role of genetic screening

Familial Mediterranean fever is an autosomal recessive disorder characterized by paroxysmal episodes of fever and serosal inflammation. The classical presentation is fever and severe recurrent abdominal pain due to serositis that lasts for one to three days and the resolves spontaneously. Between the episodes patients are asymptomatic. Ninety-five percent of patients with familial mediterranean fever have painful episodes localized to the abdomen, which is usually the dominant manifestation of the disease. Herein, we present a case of 34-year-old man with incomplete abdominal pain episode of familial mediterranean fever limited to the epigastrum and had no cardinals symptoms of this disease. The diagnosis was made by genetic screening. Successful treatment response was achieved by colchicine.

Cerebral amyloid angiopathy–associated intracerebral hemorrhage: pathology and management

Amyloid angiopathy-associated intracerebral hemorrhage (ICH) comprises 12%-15% of lobar ICH in the elderly. This growing population has an increasing incidence of thrombolysis-related hemorrhages, causing the management of hemorrhages associated with cerebral amyloid angiopathy (CAA) to take center stage. A concise reference assimilating the pathology and management of this clinical entity does not exist. Amyloid angiopathy-associated hemorrhages are most often solitary, but the natural history often progresses to include multifocal and recurrent hemorrhages. Compared with other causes of ICH, patients with CAA-associated hemorrhages have a lower mortality rate but an increased risk of recurrence. Unlike hypertensive arteriolar hemorrhages that occur in penetrating subcortical vessels, CAA-associated hemorrhages are superficial in location due to preferential involvement of vessels in the cerebral cortex and meninges. This feature makes CAA-associated hemorrhages easier to access surgically. In this paper, the authors discuss 3 postulates regarding the pathogenesis of amyloid hemorrhages, as well as the established clinicopathological classification of amyloid angiopathy and CAA-associated ICH. Common inheritance patterns of familial CAA with hemorrhagic strokes are discussed along with the role of genetic screening in relatives of patients with CAA. The radiological characteristics of CAA are described with specific attention to CAA-associated microhemorrhages. The detection of these microhemorrhages may have important clinical implications on the administration of anticoagulation and antiplatelet therapy in patients with probable CAA. Poor patient outcome in CAA-associated ICH is associated with dementia, increasing age, hematoma volume and location, initial Glasgow Coma Scale score, and intraventricular extension. The surgical management strategies for amyloid hemorrhages are discussed with a review of published surgical case series and their outcomes with a special attention to postoperative hemorrhage.

Hypertrophic cardiomyopathy and planned in vitro fertilization

Hypertrophic cardiomyopathy (HCM) is often transmitted to the offspring of affected individuals. This case report describes the role of genetic screening in a 39-year-old woman with a family history of sudden cardiac death. The patient wished to become pregnant and was seeking medical consultation. In addition to electro- and echocardiograms, genomic DNA was isolated and direct sequencing was employed to screen the patient for some of the most common genes that cause HCM. A pathogenic heterozygous mutation c.700 g > a p.Arg186Gln in TNNI3 was identified, which was not found in 200 normal control chromosomes. Mutation-specific genetic testing was also performed in four family members, and the same mutation was absent. Genetic screening appears cost effective in familiar members with a known mutation, provides important information about the affected individual, and can facilitate the future management of family members and offspring.

Phenotypic variation and genetic polymorphism of low-density lipoprotein exon 4 receptor gene among Jordanian familial hypercholesterolemia patients

Purpose. The aim of this study was to measure lipid profiles among severe and mild familial hypercholestrolemic (FH) patients and to screen unrelated families for LDL receptor (LDLR) gene polymorphism. Methods. Fifteen FH patients and six controls were enrolled in the study. Total cholesterol (CH), triglyceride (TG), high-density lipoprotein (HDL-cholesterol), low-density lipoprotein (LDL) and ApoB-100 levels were measured spectrophotometrically. Patients were classified clinically into severe and mild, based on lipid profile phenotype and the presence of cardiovascular manifestation at the age of disease onset. Low-density lipoprotein exon 4 receptor gene polymorphism was screened by the SSCP method. Results. FH severe phenotype patients had significantly higher total cholesterol levels (14.34 ± 1.14) mmol/L as compared with mild FH phenotype (10.13 ± 1.23 mmol/L) and experienced earlier symptoms in the childhood (9.25 ± 3.22) years as compared with those of mild phenotype, who did not experience symptoms until the mid of the fourth decade of life (36.7 ± 5.25 years). No significant difference was found between HDL-cholesterol, LDL-cholesterol, ApoB-100 among severe FH as compared with mild FH patients. All FH pedigrees showed the autosomal dominant mode of inheritance. SSCP results showed a wide spectrum of LDL exon 4 gene polymorphism among severe and mild phenotypes, which differed from control. Conclusions. There are statistical differences between severe and mild phenotype FH patients in total cholesterol, triglyceride and the age of biological expression among FH Jordanians. FH patients showed a wide spectrum of gene polymorphism within the LDLR exon 4 gene. These polymorphisms were different among FH families; this may be related to founder factors, such as the degree of consanguinity among FH patients’ parents and shed light on the importance of the role of genetic screening and counseling in reducing the risk of occurrence of the new severe FH phenotypes that develop severe complications early in life and need LDL aphresis, as well as on the importance of cascade screening to trace and identify people at genetic risk, using family tracing, for an early diagnosis of the mild FH phenotypes that can be treated with lipid lowering therapy and life style changes early to prevent later cardiovascular complications. Keywords: familial hypercholesterolemia, low-density lipoprotein, receptor, homozygous, heterozygous, SSCP, Apo B-100

Role of Genetic Screening in a Chinese Woman of Childbearing Age with Hypertrophic Cardiomyopathy

Objectives The objective of this study was to evaluate the role of genetic screening in a Chinese woman of childbearing age with hypertrophic cardiomyopathy.Methods and Results One 39 year-old woman with presyncope for 10 years was admitted.Both of her father and her son died of sudden death and she strongly desire to get another baby. A series of clinical and laboratory studies were performed. Hypertrophic cardiomyopathy was diagnosed finally and implantable Cardioverter Defibrillator was implanted to prevent sudden cardiac death for her.Genomic DNA was isolated and the most common causal genes for hypertrophic cardiomyopathy were screened.A known pathogenetic heterozygous mutation c.700 g>a(p.Argl86Gln) in TNNI3 was found,which was not found in 100 normal control individuals matched for age,sex and geographical region.Because 50%probability of the pathogenetic mutation is inherited to the offsprings,she will get a healthy baby in vitro fertilization which the egg comes from a healthy female donor to prevent from the inherited HCM.Conclusions We found a pathogenetic TNNI3 mutation in a Chinese woman of childbearing age with hypertrophic cardiomyopathy.The genetic screening definite DNA-based diagnosis and help to design a healthy fertilization in vitro for female with hypertrophic cardiomyopathy.

Role of genetic screening in identifying susceptibility to acute fatty liver of pregnancy

Acute fatty liver of pregnancy is a devastating disorder that can significantly affect the morbidity and mortality of both mother and fetus. This Viewpoint discusses the prevalence and implications of this disorder and examines the role of genetic screening in helping to identify patients at risk for this disease.

Genetics of common disease: implications for therapy, screening and redefinition of disease.

Susceptibility to most common human diseases is, at least in part, determined by genetic factors. Rapid progress is being made in defining these genetic determinants for a range of diseases including breast cancer, colon cancer, diabetes, arthritis and dementia. The ability to define susceptibility in genetic terms has already led to a reclassification of some of these diseases on genetic and mechanistic grounds. This information is likely to have a profound effect on our approach to human diseases as it will allow a better definition of these disorders, permitting more effective therapeutic intervention, and will lead to both a more precise understanding of the natural history of these diseases and the possibility of identifying populations at risk. An understanding of the mechanisms underlying disease susceptibilty will also improve our ability to develop rational therapeutic interventions for many of these diseases. The role of genetic screening in these common diseases will be discussed, particularly in regard to the application of health care in populations.

RET mutations in multiple endocrine neoplasia type 2 and Hirschsprung disease.

Mutations in the RET proto-oncogene have been found in a large proportion of families affected by the multiple endocrine neoplasia type 2 syndrome and in familial and sporadic Hirschsprung disease. This review discusses the role of the RET receptor tyrosine kinase in the etiology of these dominantly inherited disorders of neural crest development. In addition, the role of genetic screening is considered in the identification and clinical management of individuals at risk for these diseases.

The role of genetic screening in the management of hereditary malignancy.

The identification of closely linked markers for several genetic syndromes has resulted in the routine identification of gene carriers for these disorders before the development of disease manifestations. The experiences with the multiple endocrine neoplasia syndromes, multiple endocrine neoplasia type 2 in particular, provide one example of how genetic testing can be combined with ongoing screening, treatment and support mechanisms to help families cope with the treatment realities and the psychosocial aspects of genetic disease.