Inherited chromosomally-integrated human herpes virus 6 confounding test results in a patient with myelitis and optic neuritis - A case report

A case of the 'perfect storm' of myelin oligodendrocyte glycoprotein (MOG) antibody-mediated myelitis, human herpesvirus 6 (HHV-6) reactivation, and COVID-19 infection was reported in 2021. This article reports a case of a similarly observed clinical triad, but with a different conclusion and explanation supported by laboratory test results and evidence from our literature review.

Clinical and Genetic Characterization of RDH12-Retinal Dystrophy in a South American Cohort

PURPOSE

To characterize the largest cohort of individuals with retinol dehydrogenase 12 (RDH12)-retinal dystrophy to date, and the first one from South America.

DESIGN

Retrospective multicenter international study.

SUBJECTS

Seventy-eight patients (66 families) with an inherited retinal dystrophy and biallelic variants in RDH12.

METHODS

Review of clinical notes, ophthalmic images, and molecular diagnosis.

MAIN OUTCOME MEASURES

Visual function, retinal imaging, and characteristics were evaluated and correlated.

RESULTS

Thirty-seven individuals self-identified as Latino (51%) and 34 as White (47%). Sixty-nine individuals (88%) had Leber congenital amaurosis (LCA)/early-onset severe retinal dystrophy. Macular and midperipheral atrophy were seen in all patients from 3 years of age. A novel retinal finding was a hyperautofluorescent ring in 2 young children with LCA. Thirty-nine patients (50%) had subsequent visits, with mean follow-up of 6.8 ± 7.3 (range, 0-29) years. Eight variants (21%) were previously unreported, and the most frequent variant was c.295C>A, p.Leu99Ile, present in 52 alleles of 32 probands. Individuals with LCA homozygous for p.Leu99Ile (31%) had a later age of onset, a slower rate of best-corrected visual acuity decrease, the largest percentage of patients with mild visual impairment, and were predicted to reach legal blindness at an older age than the rest of the cohort.

CONCLUSIONS

By describing the largest molecularly confirmed cohort to date, improved understanding of disease progression was possible. Our detailed characterization aims to support research and the development of novel therapies that may have the potential to reduce or prevent vision loss in individuals with RDH12-associated retinal dystrophy.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures.

CRX haploinsufficiency compromises photoreceptor precursor translocation and differentiation in human retinal organoids

BACKGROUND

The CRX-associated autosomal dominant retinopathies suggest a possible pathogenic mechanism of gene haploinsufficiency. However, based on reported human patient cases and studies with mouse models, it is hard to confirm the specific weight of haploinsufficiency in pathogenesis due to the interspecies gaps between gene expression and function.

METHODS

We created monoallelic CRX by replacing one allele with tdTomato in human embryonic stem cells (hESCs) and subsequently dissect pathogenesis in hESCs-derived retinal organoids. We used transcriptome and immunofluorescence analyses to dissect phenotypic differences between CRX-monoallelic knockout and control wildtype organoids. For location analysis of CRX+ cells, a CRX-expression-tracing system was constructed in control hESCs. We implemented long-term live-cell imaging to describe the translocation of CRX+ cells between two groups in early organoid differentiation. The expression pattern of these dynamic differences was validated using RNA-seq and immunofluorescence assays.

RESULTS

We identified delayed differentiation of outer nuclear layer (ONL) stratification along with thinner ONL, serious loss of photoreceptor outer segments, as well as downregulated expression of gene for phototransduction and inner/outer segment formation. By live-cell imaging and immunostaining, we observed the overtension of actomyosin network and the arrested translocation of monoallelic CRX+ cells in the early stage of retinal differentiation.

CONCLUSIONS

We confirmed that gene haploinsufficiency is the mechanism for the dominant pathogenicity of CRX and discovered that CRX regulated postmitotic photoreceptor precursor translocation in addition to its specification of photoreceptor cell fates during human retinal development. These findings revealed a new underlying mechanism of CRX dominant pathogenesis and provided a new clue for the treatment of CRX-associated human retinopathies.

CHD2 pathogenic nonsense variant in a three-generation family with variable phenotype and a paracentric inversion 16: Case report

Chromosomal inversions are usually balanced structural chromosomal rearrangements that do not have an impact on the clinical phenotype of a carrier. The main clinical consequence of inversions is the risk for unbalanced gametes and offspring with severe phenotypes. Rarely though, inversions are associated with a phenotype, mainly due to submicroscopic Copy Number Variants (CNVs) or disruption at the breakpoints of a functionally important gene and/or genomic elements. In this study, a paracentric inversion of chromosome 16 [inv(16)(q22.3q24.1)] was identified in a three-generation family with discordant phenotypes with/without epilepsy and/or intellectual impairment, as well as with an unaffected carrier. This finding was confirmed by fluorescence in situ hybridization (FISH). Genetic investigation, initially with chromosomal microarray (CMA), did not reveal any copy number variants. Finally, Clinical Exome Sequencing (CES), detected the presence of a pathogenic nonsense variant (rs797044912) in the Chromodomain Helicase DNA-binding protein 2 (CHD2) gene [NM_001271.4:c.5035C>T p.(Arg1679Ter)]. CHD2 pathogenic variants have been associated with Developmental and Epileptic Encephalopathy-94 (DEE-94), a rare yet severe condition, characterized by developmental delay, seizures with an early onset, intellectual impairment, autism spectrum disorder, and sometimes behavioral issues. Family testing showed that the variant segregated with phenotypic heterogeneity in the affected individuals and appears to be causative. To the best of our knowledge, this is the first CHD2 pathogenic variant segregating in a three-generation family and the fourth familial case reported. These results further support our previous findings that familial, balanced rearrangements with discordant phenotypes in the same family are, in the vast majority, coincidental.

Coats-like Vasculopathy in Inherited Retinal Disease: Prevalence, Characteristics, Genetics, and Management

PURPOSE

To describe the largest, most phenotypically and genetically diverse cohort of patients with inherited retinal disease (IRD)-related Coats-like vasculopathy (CLV).

DESIGN

Multicenter retrospective cohort study.

PARTICIPANTS

A total of 67 patients with IRD-related CLV.

METHODS

Review of clinical notes, ophthalmic imaging, and molecular diagnosis from 2 international centers.

MAIN OUTCOME MEASURES

Visual function, retinal imaging, management, and response to treatment were evaluated and correlated.

RESULTS

The prevalence of IRD-related CLV was 0.5%; 54% of patients had isolated retinitis pigmentosa (RP), 21% had early-onset severe retinal dystrophy, and less frequent presentations were syndromic RP, sector RP, cone-rod dystrophy, achromatopsia, PAX6-related dystrophy, and X-linked retinoschisis. The overall age of patients at CLV diagnosis was 30.7 ± 16.9 years (1-83). Twenty-one patients (31%) had unilateral CLV, and the most common retinal features were telangiectasia, exudates, and exudative retinal detachment (ERD) affecting the inferior and temporal retina. Macular edema/schisis was observed in 26% of the eyes, and ERD was observed in 63% of the eyes. Fifty-four patients (81%) had genetic testing, 40 of whom were molecularly solved. Sixty-six eyes (58%) were observed, 17 eyes (15%) were treated with a single modality, and 30 eyes (27%) had a combined approach. Thirty-five eyes (31%) were "good responders," 42 eyes (37%) were "poor responders," 22 eyes (19%) had low vision at baseline and were only observed, and 12 eyes (11%) did not have longitudinal assessment. Twenty-one observed eyes (62%) responded well versus 14 (33%) treated eyes. Final best-corrected visual acuity was significantly worse than baseline (P = 0.002); 40 patients (60%) lost 15 ETDRS letters or more over follow-up in 1 or both eyes, and 21 patients (31%) progressed to more advanced stages of visual impairment.

CONCLUSIONS

Inherited retinal disease-related CLV is rare, sporadic, and mostly bilateral; there is no gender predominance, and it can occur in diverse types of IRD at any point of the disease, with a mean onset in the fourth decade of life. Patients with IRD-related CLV who have decreased initial visual acuity, ERD, CLV changes affecting 2 or more retinal quadrants, and CRB1-retinopathy may be at higher risk of a poor prognosis.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

CERKL-Associated Retinal Dystrophy: Genetics, Phenotype, and Natural History

PURPOSE

To analyze the clinical characteristics, natural history, and genetics of CERKL-associated retinal dystrophy in the largest series to date.

DESIGN

Multicenter retrospective cohort study.

SUBJECTS

Forty-seven patients (37 families) with likely disease-causing CERKL variants.

METHODS

Review of clinical notes, ophthalmic images, and molecular diagnosis from 2 international centers.

MAIN OUTCOME MEASURES

Visual function, retinal imaging, and characteristics were evaluated and correlated.

RESULTS

The mean age at the first visit was 29.6 ± 13.9 years, and the mean follow-up time was 9.1 ± 7.4 years. The most frequent initial symptom was central vision loss (40%), and the most common retinal feature was well-demarcated areas of macular atrophy (57%). Seventy-seven percent of the participants had double-null genotypes, and 64% had electrophysiological assessment. Among the latter, 53% showed similar severity of rod and cone dysfunction, 27% revealed a rod-cone, 10% a cone-rod, and 10% a macular dystrophy dysfunction pattern. Patients without double-null genotypes tended to have fewer pigment deposits and included a higher proportion of older patients with a relatively mild electrophysiological phenotype. Longitudinal analysis showed that over half of the cohort lost 15 ETDRS letters or more in ≥ 1 eye during the first 5 years of follow-up.

CONCLUSIONS

The phenotype of CERKL-retinal dystrophy is broad, encompassing isolated macular disease to severe retina-wide involvement, with a range of functional phenotypes, generally not fitting in the rod-cone/cone-rod dichotomy. Disease onset is often earlier, with more severe retinal degenerative changes and photoreceptor dysfunction, in nullizygous cases.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Ophthalmic Disease and Screening in Breeding Dogs

This article describes the history and infrastructure associated with canine breed-related eye screening and certification by Diplomates of the American College of Veterinary Ophthalmologists. Some of the common or otherwise particularly problematic specific inherited ophthalmic conditions are discussed.

Congenital, Inherited Bilateral Amastia in a Quarter Horse Mare

Congential amastia, a medical condition in which mammary tissue fails to develop, was detected in a 3-year-old Quarter Horse mare. The dam of the mare was also afflicted with amastia, suggesting that the condition was due to an inherited genetic mutation as noted in other species. In addition, on presentation the mare had a purulent vaginal discharge secondary to a pyometra.

Implantable Devices in Genetic Heart Disease: Disease-Specific Device Selection and Programming

Diagnosis and risk stratification of rare genetic heart diseases remains clinically challenging. In many cases, there are few data and insufficient numbers to support randomized controlled trials. While implantable cardioverter defibrillator (ICD) use is vital to protect higher-risk individuals from life-threatening ventricular arrhythmias, low-risk individuals also require protection from unnecessary ICDs and their associated complications. Once an ICD has been implanted, appropriate device programming is essential to ensure maximal protection while balancing the risks of inappropriate therapy.

Macrothrombocytopenia: Role of Automated Platelet Data in Diagnosis

Purpose

Inherited macrothrombocytopenia is an underdiagnosed condition and may result in misdiagnosis and inappropriate management. This research was done to study this condition in a hospital setting.

Materials and Methods

This study was conducted over 6 months in a teaching hospital. Patients whose complete blood count (CBC) samples were sent to the hematology laboratory were included. Patients were suspected to have inherited macrothrombocytopenia according to pre-defined criteria. Demographic information, automated CBC and peripheral smear examination was carried out. Seventy five healthy individuals and 50 patients with secondary thrombocytopenia were also analyzed.

Results

Likely inherited macrothrombocytopenia was identified in 75 patients. Automated platelet count in these patients ranged from 26 × 10^9/L to 106 × 10^9/L while MPV ranged from 11.0 to 13.6 fL. There was significant difference (p < .001) in mean platelet volume (MPV) and platelet large cell ratio (P-LCR) amongst patients with likely inherited macrothrombocytopenia, those with secondary thrombocytopenia and the control group. Mean platelet diameter was significantly higher (3.5 ± 1.1μm) in patients with likely inherited macrothromboctopenia compared to those with secondary thrombocytopenia (2.4 ± 0.7μm) and control group (1.9 ± 0.7μm). All patients with suspected inherited macrothrombocytopenia showed abnormal platelet histograms with descending limb in the high volume and red cell zone. Four distinct histogram patterns were identified.

Conclusion

Inherited macrothrombocytopenia is an underdiagnosed condition. The patient's history, clinical examination, judicious use of automated CBC data including platelet histograms and careful review of the peripheral blood smear are useful tools to suspect this condition.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12288-022-01590-6.

Carer burden in rare inherited diseases: a literature review and conceptual model

BACKGROUND

Carers of people living with rare diseases report heavy burden and a plethora of unmet needs. A previous parental supportive care needs framework has described the needs of parents of children living with rare diseases, but it is not specific to rare inherited diseases (RIDs) and does not include non-parental carers. We conducted a targeted literature review to: (1) ascertain the burden/supportive care needs of informal carers of people living with RIDs, (2) understand the burden/supportive care needs unique to these carers, and (3) develop a conceptual model based on the findings.

METHODS

A targeted literature review searching Embase and Medline between 2000 and 2020 was conducted to identify journal articles describing the burden/supportive care needs of all types of informal carers of people living with RIDs. Thematic analysis was conducted on the articles to develop a conceptual model.

RESULTS

After screening and quality appraisal, 31 journal articles were analysed, representing 70 RIDs (including bleeding, bone, central nervous system, multisystem and inherited metabolic disorders). Most articles (74%) focused on parent carer samples. The conceptual model has three overarching domains, encompassing 13 themes: (1) Living with Rare Inherited Disease (Being a Carrier of Rare Disease, Carer Perceptions, Disease Severity); (2) Carer Needs/Burden (Social/Community, Well-being, Information, Practical); and (3) Carer Coping Strategies (Acceptance, Support Systems, Gratitude and Hope, Faith, Quest for Knowledge, Establish a Routine). Our conceptual model uniquely describes carers' transmission guilt, clinically relevant depression and anxiety, worry about future family members living with the RID, and challenging decisions about having more children. Carers often implemented psychological, structural, practical, and social coping strategies to manage their burdens.

CONCLUSIONS

The identified burdens underscore the need for the provision of information and social support to these carers. Future research should focus on the (1) potential mediators/moderators of carers' burden, (2) needs of carers within the wider family including siblings and grandparents, (3) needs of carers of adults living with RIDs, including spouses and children, and (4) biopsychosocial effect on carers living with a RID themselves. Our conceptual model offers a potential tool for healthcare professionals to utilise during the provision of support to carers.

Management of patients with inherited bleeding disorders in oral surgery: A 13-year experience

INTRODUCTION

The management of patients with inherited bleeding disorders in oral surgery requires the systematic evaluation of bleeding risk and the setting up of an adequate treatment protocol by the referring haematologist, defining a replacement therapy and a recommended length of hospital stay. The purpose of this study was to determine the bleeding risk associated with oral surgery for each type of inherited bleeding disorder and to evaluate the efficacy of the treatment protocols set up in our tertiary care center.

MATERIALS AND METHODS

We included all patients with an inherited bleeding disorder, managed in our oral and maxillofacial surgery department with a treatment protocol set up by our local Haemophilia Treatment Centre for an oral surgical procedure.

RESULTS

Between January 2006 and December 2018, 295 treatment protocols were set up for the management of patients with haemorrhagic risk in oral surgical procedures. Of these, 203 were scheduled to take place in our department. A total of 180 oral surgical procedures for 147 patients were included. The incidence of bleeding complications in our study was 4.44% (8 out of 180) with a significantly higher risk in patients with haemophilia, the mean time to onset of bleeding was 11 days.

DISCUSSION

The use of a treatment protocol for the management of patients with inherited bleeding disorders in oral surgery seems effective. Our rate of bleeding complications was comparable to data in the literature, and often lower.

Unexpected actionable genetic variants revealed by multigene panel testing of patients with uterine cancer

OBJECTIVE

Hereditary uterine cancer (UC) is traditionally associated with pathogenic/likely pathogenic germline variants (PGVs) in Lynch syndrome genes or PTEN; however, growing evidence supports a role for other genes that may reveal new clinical management options. In this study we assessed the prevalence and potential clinical impact of PGVs identified in UC patients referred for comprehensive germline genetic testing that combined testing for Lynch syndrome, PTEN, and other cancer predisposition genes.

METHODS

Prevalence of PGVs in patients referred to a single clinical lab for germline genetic testing with an indication of uterine or endometrial cancer were retrospectively assessed and compared by syndrome type, patient age at testing, and self-reported ancestry. Potential clinical actionability of PGVs was based on established guidelines for clinical management, targeted therapies, and clinical trial eligibility.

RESULTS

PGVs were detected in 13.6% of the cohort (880/6490). PGVs were most frequently observed in Lynch syndrome genes (60.4%) and PTEN (1.5%), with 38.1% in another cancer predisposition gene (i.e., CHEK2, BRCA1/BRCA2). PGV prevalence was similar for patients <50 years and those ≥50 years (15.1% vs 13.2%). Nearly all PGVs (97.2%) were associated with guideline-recommended management, including cascade testing; 60.5% were associated with FDA-approved therapies; and 35.2% were associated with clinical trials.

CONCLUSIONS

Focusing germline testing on Lynch syndrome genes and PTEN and limiting testing to patients <50 years of age at diagnosis may overlook a substantial proportion of UC patients who harbor actionable PGVs. Universal comprehensive genetic testing of UC patients could benefit many patients and at-risk family members.

Equine Neuroaxonal Dystrophy and Degenerative Myeloencephalopathy

Neuroaxonal degenerative disease in the horse is termed equine neuroaxonal dystrophy (eNAD), when pathologic lesions are localized to the brainstem and equine degenerative myeloencephalopathy (EDM) and degenerative changes extend throughout the spinal cord. Both pathologic conditions result in identical clinical disease, most commonly characterized by the insidious onset of ataxia during early development. However, later onset of clinical signs and additional clinical features, such as behavior changes, is also observed. A definitive diagnosis of eNAD/EDM requires histologic evaluation of the caudal medulla and cervicothoracic spinal cord. Strong evidence has suggested that eNAD/EDM is an inherited disorder and there seems to be a role for vitamin E acting as an environmental modifier to determine the overall severity of the phenotype of horses affected with eNAD/EDM.

Autosomal dominant tubulointerstitial kidney disease: more than just HNF1β

Autosomal dominant tubulointerstitial kidney disease (ADTKD) refers to a group of disorders with a bland urinary sediment, slowly progressive chronic kidney disease (CKD), and autosomal dominant inheritance. Due to advances in genetic diagnosis, ADTKD is becoming increasingly recognized as a cause of CKD in both children and adults. ADTKD-REN presents in childhood with mild hypotension, CKD, hyperkalemia, acidosis, and anemia. ADTKD-UMOD is associated with gout and CKD that may present in adolescence and slowly progresses to kidney failure. HNF1β mutations often present in childhood with anatomic abnormalities such as multicystic or dysplastic kidneys, as well as CKD and a number of other extra-kidney manifestations. ADTKD-MUC1 is less common in childhood, and progressive CKD is its sole clinical manifestation, usually beginning in the late teenage years. This review describes the pathophysiology, genetics, clinical characteristics, diagnosis, and treatment of the different forms of ADTKD, with an emphasis on diagnosis. We also present data on kidney function in children with ADTKD from the Wake Forest Rare Inherited Kidney Disease Registry.

An investigation into the role of inherited CEACAM gene family variants and colorectal cancer risk

Objective

This study was designed to determine if CEACAM mutations are associated with inherited risk of colorectal cancer. Recently, protein-truncating mutations in the CEACAM gene family were associated with inherited breast cancer risk. That discovery, along with aberrant expression of CEACAM genes in colorectal cancer tumors and that colorectal cancer and breast cancer share many risk factors, including genetics, inspired our team to search for inherited CEACAM mutations in colorectal cancer cases. Specifically utilizing The Cancer Genome Atlas (TCGA) blood-derived whole-exome sequencing data from the colorectal cancer cohort, rare protein-truncating variants and missense variants were investigated through single variant and aggregation analyses in European American and African American cases and compared to ethnic-matched controls.

Results

A total of 34 and 14 different CEACAM variants were identified in European American and African American colorectal cancer cases, respectively. Nine missense variants were individually associated with risk, two in African Americans and seven in European Americans. No identified protein-truncating variants were associated with CRC risk in either ethnicity. Gene family and gene-specific aggregation analyses did not yield any significant results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-05907-6.

The effect of inbreeding, body size and morphology on health in dog breeds

Background

Dog breeds are known for their distinctive body shape, size, coat color, head type and behaviors, features that are relatively similar across members of a breed. Unfortunately, dog breeds are also characterized by distinct predispositions to disease. We explored the relationships between inbreeding, morphology and health using genotype based inbreeding estimates, body weight and insurance data for morbidity.

Results

The average inbreeding based on genotype across 227 breeds was F_adj = 0.249 (95% CI 0.235–0.263). There were significant differences in morbidity between breeds with low and high inbreeding (H = 16.49, P = 0.0004). There was also a significant difference in morbidity between brachycephalic breeds and non-brachycephalic breeds (P = 0.0048) and between functionally distinct groups of breeds (H = 14.95 P < 0.0001). Morbidity was modeled using robust regression analysis and both body weight (P < 0.0001) and inbreeding (P = 0.013) were significant (r² = 0.77). Smaller less inbred breeds were healthier than larger more inbred breeds.

Conclusions

In this study, body size and inbreeding along with deleterious morphologies contributed to increases in necessary health care in dogs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40575-021-00111-4.

Liver transplantation for pediatric inherited metabolic liver diseases

Liver transplantation (LT) remains the gold standard treatment for end stage liver disease in the pediatric population. For liver based metabolic disorders (LBMDs), the decision for LT is predicated on a different set of paradigms. With improved outcomes post-transplantation, LT is no longer merely life saving, but has the potential to also significantly improve quality of life. This review summarizes the clinical presentation, medical treatment and indications for LT for some of the common LBMDs. We also provide a practical update on the dilemmas and controversies surrounding the indications for transplantation, surgical considerations and prognosis and long terms outcomes for pediatric LT in LBMDs. Important progress has been made in understanding these diseases in recent years and with that we outline some of the new therapies that have emerged.

A look into retinal organoids: methods, analytical techniques, and applications

Inherited retinal diseases (IRDs) cause progressive loss of light-sensitive photoreceptors in the eye and can lead to blindness. Gene-based therapies for IRDs have shown remarkable progress in the past decade, but the vast majority of forms remain untreatable. In the era of personalised medicine, induced pluripotent stem cells (iPSCs) emerge as a valuable system for cell replacement and to model IRD because they retain the specific patient genome and can differentiate into any adult cell type. Three-dimensional (3D) iPSCs-derived retina-like tissue called retinal organoid contains all major retina-specific cell types: amacrine, bipolar, horizontal, retinal ganglion cells, Müller glia, as well as rod and cone photoreceptors. Here, we describe the main applications of retinal organoids and provide a comprehensive overview of the state-of-art analysis methods that apply to this model system. Finally, we will discuss the outlook for improvements that would bring the cellular model a step closer to become an established system in research and treatment development of IRDs.

Familial Risk of Inflammatory Bowel Disease: A Population-Based Cohort Study in South Korea

BACKGROUND & AIMS

Despite the rapid increase in inflammatory bowel disease (IBD), population-level familial risk estimates of IBDs still are lacking in Asian-Pacific countries. We aimed to quantify the familial risk of incident IBD among first-degree relatives (FDRs) of individuals with IBD according to age, sex, and familial relationship.

METHODS

Using the South Korea National Health Insurance database (2002-2017), which has complete population coverage and confirmed accuracy of both FDR information and IBD diagnoses, we constructed a cohort of 21,940,795 study subjects comprising 12 million distinct families. We calculated incidence risk ratios of ulcerative colitis (UC) or Crohn's disease (CD) in individuals of affected FDRs compared with individuals without affected FDRs.

RESULTS

Of 45,717 individuals with UC and 17,848 individuals with CD, 3.8% and 3.1% represented familial cases, respectively. Overall, there was a 10.2-fold (95% CI, 9.39-11.1) and a 22.1-fold (95% CI, 20.5-24.5) significantly higher adjusted risk of UC and CD among FDRs of individuals with vs without IBD. Familial risk was highest among twins, followed by nontwin siblings, and then offspring of affected parents. Familial risk generally was higher within generations (sibling-sibling) vs between generations (parent-offspring). Familial risk also increased with the increasing number of affected FDRs.

CONCLUSIONS

According to this population-based analysis, there is a substantially increased risk of IBD among FDRs of affected individuals, with the highest risk among siblings and for CD. These findings might help with an earlier diagnosis and appropriate therapeutic intervention in FDRs of individuals with IBD. Dedicated studies are needed to evaluate the contributions of shared early-in-life environmental exposures and genetic factors.

Germline sequence analysis of RABL3 in a large series of pancreatic ductal adenocarcinoma patients reveals no evidence of deleterious variants

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with a 5-year survival rate of less than 10%. Individuals with a pathogenic germline variant in a pancreatic cancer susceptibility gene are at an increased risk of developing pancreatic cancer. Understanding the inherited genetic basis of pancreatic tumor development provides a unique opportunity to improve patient care and outcomes. For example, relatives of a patients with PDAC who have a pathogenic germline variant in a pancreatic cancer susceptibility gene are eligible for disease surveillance where cancers may be detected early, and 5-year survival greatly improved. Furthermore, for some patients with PDAC and a pathogenic germline variant in a pancreatic cancer susceptibility gene, their tumors may be susceptible to specific anti-cancer therapies. Recently, RABL3 was identified as a pancreatic cancer susceptibility gene. To validate these findings and inform clinical translation, we determined the prevalence of deleterious RABL3 variants in a large cohort of 1037 patients with PDAC that had undergone either whole genome or whole exome germline sequencing. We identified two synonymous variants and four missense variants classified as variants of unknown significance. We found no pathogenic RABL3 variants, indicating that the maximum prevalence of such variants in patients with PDAC is less than 0.36% (minor allele frequency 0, 97.5% one-sided confidence interval: 0-0.0036). This finding has important implications for germline genetic testing of patients with PDAC.

Examination of ATM, BRCA1, and BRCA2 promoter methylation in patients with pancreatic cancer

BACKGROUND

Pancreatic cancer is a lethal disease with a poor 5-year survival rate. Pathogenic germline variants in the coding regions of ATM, BRCA1, and BRCA2 are found in up to 4.8% of pancreatic cancer patients. Germline promoter methylation and gene silencing arising from a germline variant or through other mechanisms have been described as a cause of tumor suppressor gene inactivation.

METHODS

We measured the level of promoter methylation of the ATM, BRCA1, and BRCA2 genes in peripheral blood lymphocytes from 655 patients with pancreatic cancer using real-time PCR.

RESULTS

No evidence of germline promoter methylation of any of these genes was found. Promoter methylation levels were minimal with no patient having promoter methylation greater than 3.4%, 3.3%, and 7.6% for ATM, BRCA1 and BRCA2, respectively, well below levels found in patients who have inherited promoter methylation (∼50%).

CONCLUSIONS

We found no evidence of germline promoter methylation for the pancreatic susceptibility genes ATM, BRCA1 and BRCA2 in patients with pancreatic cancer. This study reveals that constitutive germline methylation of promoter CpG islands is rare in pancreatic cancer.

Development and pilot testing of a training for bilingual community education professionals about hereditary breast and ovarian cancer among Latinas: ÁRBOLES Familiares

Cancer health disparities remain a significant problem in the USA, compounded by lack of access to care, language barriers and systemic biases in health care. These disparities are particularly evident in areas such as genetics/genomics. For example, Latinas at high risk for hereditary breast and ovarian cancer (HBOC) have extremely low rates of genetic counseling/testing. Long-standing barriers and inequities in access to services such as genetic counseling and testing require innovative solutions. One solution can involve training community outreach and education professionals (CORE-Ps) to bridge the gap between underserved communities and genetic specialists. We sought to develop and pilot test a training program for English-Spanish bilingual CORE-Ps to reduce disparities in access to and uptake of genetic services among Latino populations. Guided by Adult Learning Theory and with input from multiple stakeholders, we developed ÁRBOLES Familiares (Family Trees), an in-person and online training program for bilingual CORE-Ps to facilitate identification, referral, and navigation of Latinas to genetic counseling/testing. We conducted a pilot test of 24 CORE-Ps recruited from across the United States and assessed knowledge, genetic literacy, and self-efficacy at baseline and follow-up. At follow-up, participants in the pilot with complete baseline and follow-up data (N = 15) demonstrated significant improvements in HBOC knowledge, genetic literacy, self-efficacy and reports of fewer barriers to identify/navigate Latinas (ps < .05). Qualitative assessment identified ways to improve the training curriculum. Pilot results suggest ÁRBOLES is a promising approach for training CORE-Ps to identify and refer high-risk Latinas to genetic services. Next steps involve further refinement of ÁRBOLES, development of an online toolkit, and adaptation for virtual delivery.

Cardiac K+ Channels and Channelopathies

The physiological heart function is controlled by a well-orchestrated interplay of different ion channels conducting Na⁺, Ca²⁺ and K⁺. Cardiac K⁺ channels are key players of cardiac repolarization counteracting depolarizating Na⁺ and Ca²⁺ currents. In contrast to Na⁺ and Ca²⁺, K⁺ is conducted by many different channels that differ in activation/deactivation kinetics as well as in their contribution to different phases of the action potential. Together with modulatory subunits these K⁺ channel α-subunits provide a wide range of repolarizing currents with specific characteristics. Moreover, due to expression differences, K⁺ channels strongly influence the time course of the action potentials in different heart regions. On the other hand, the variety of different K⁺ channels increase the number of possible disease-causing mutations. Up to now, a plethora of gain- as well as loss-of-function mutations in K⁺ channel forming or modulating proteins are known that cause severe congenital cardiac diseases like the long-QT-syndrome, the short-QT-syndrome, the Brugada syndrome and/or different types of atrial tachyarrhythmias. In this chapter we provide a comprehensive overview of different K⁺ channels in cardiac physiology and pathophysiology.

Inherited unbalanced translocation (4p16.3p15.32 duplication/8p23.3p23.2deletion) in the four generation pedigree with intellectual disability/developmental delay

Chromosomal copy number variants (CNVs) are an important cause of congenital malformations and mental retardation. This study reported a large Chinese pedigree (4-generation, 76 members) with mental retardation caused by chromosome microduplication/microdeletion. There were 10 affected individuals with intellectual disability (ID), developmental delay (DD), and language delay phenotypes. SNP array analysis was performed in the proband and eight patients and found all of them had a microduplication of chromosome 4p16.3p15.2 and a microdeletion of chromosome 8p23.3p23.2. The high-resolution karyotyping analysis of the proband had unbalanced karyotype [46, XY, der(8)t(4;8)(p15.2;p23.1)mat], his mother had balanced karyotype [46, XX, t(4;8) (p15.2;p23.1)], whereas his father had normal karyotype [46,XY]. Fluorescence in situ hybridization (FISH) analysis further confirmed that the proband’s mother had a balanced translocation between the short arm terminal segment of chromosome 4 and the short arm end segment of chromosome 8, ish t(4;8)(8p + ,4q + ;4p + ,8q +). In conclusion, all the patients inherited chromosomes 8 with 4p16.3p15.2 duplication and 8p23.3p23.2 deletion from their parental balanced translocation, which might be the cause of the prevalence of intellectual disability. Meanwhile, 8p23.3p23.2 deletion, rather than 4p16.3p15.2 duplication might cause a more severe clinical syndrome.

Inherited Bone Marrow Failure Syndromes: Biology and Diagnostic Clues

Inherited bone marrow failure syndromes are a group of genetic disorders associated with bone marrow production defects resulting in single or multiple cytopenias. Many of these disorders predispose the patient to hematologic and nonhematologic malignancies, requiring life-long follow-up. A positive family history of hematologic disorders or malignancies is frequent, as these disorders commonly run in families, and selection of family members as potential bone marrow donors should be performed with caution to avoid transplanting potentially defective stem cells. This review highlights the most common genetic disorders associated with bone marrow failure.

Arching deep brain stimulation in dystonia types

Although medical treatment including botulinum toxic injection is the first-line treatment for dystonia, response is insufficient in many patients. In these patients, deep brain stimulation (DBS) can provide significant clinical improvement. Mounting evidence indicates that DBS is an effective and safe treatment for dystonia, especially for idiopathic and inherited isolated generalized/segmental dystonia, including DYT-TOR1A. Other inherited dystonia and acquired dystonia also respond to DBS to varying degrees. For Meige syndrome (craniofacial dystonia), other focal dystonia, and some rare inherited dystonia, further evidences are still needed to evaluate the role of DBS. Because short disease duration at DBS surgery and absence of fixed musculoskeletal deformity are associated with better outcome, DBS should be considered as early as possible when indicated after careful evaluation including genetic work-up. This review will focus on the factors to be considered in DBS for patients with dystonia and the outcome of DBS in the different types of dystonia.

Cardiovascular Magnetic Resonance in Heritable Cardiomyopathies

Cardiovascular magnetic resonance represents the imaging modality of choice for the investigation of patients with heritable cardiomyopathies. The combination of gold-standard volumetric analysis with tissue characterization can deliver precise phenotypic evaluation of both cardiac morphology and the underlying myocardial substrate. Cardiovascular magnetic resonance additionally has an established role in risk-stratifying patients with heritable cardiomyopathy and an emerging role in guiding therapies. This article explores the application and utility of cardiovascular magnetic resonance techniques with specific focus on the major heritable cardiomyopathies.

Biochemical and molecular analysis of the beta-globin gene and LCR region on Saudi β-thalassemia patients

Introduction

Beta-thalassemias are a group of inherited blood disorders caused by reduced or absent synthesis of beta chain of hemoglobin resulting in variable phenotypes ranging from clinically asymptomatic individuals to severe anemia symptoms. The objective of this study is to screen for the whole beta gene globulin and the LCR region and its clinical relevance in β-Thalassemia patients.

Methods

In this study, we collected 140 blood patients' samples with beta-thalassemia from different areas of Saudi Arabia. DNA was then extracted then the molecular scanning for the whole β-globin gene and the Locus control region (β-LCR) for patients' samples, was run using PCR.

Results

Sixty one mutations found in this study, including 22 new mutations not recorded in the database before. These deletions including: (*C-1960-1961 ca/-- del in hbb5) and (*c-519C<T homo, *c-390C<T homo in hbb6) were the highest among beta-thalassemia in the study, which indicates a strong sign of injury associated with the disease. Meanwhile, There are other mutations found most common among patients and was linked with the severity of clinical symptoms including: (c-1960-1961 ca/-- del in hbb5), (c-519C<T homo, c-390C<T homo, c-160 G<A het in hbb6), (c.315+282 G<A het, c.316-225G<A het, c.315+342 G > A het in hbb9). Interestingly, the highest percentage in gene deletion occurred in exon 03A by ∼33% of the samples, while the highest percentage in gene addition of the gene occurred in exon 03B by ∼25%.

Conclusion

This study was unique to show several new mutations that would help in diagnosis and treatment. These results should be taken further to set up better management strategies to improve outcomes.

DINAX- a comprehensive database of inherited ataxias

BACKGROUND

Neurodegenerative disorders such as hereditary ataxia often manifest overlapping symptoms and are likely to be misdiagnosed based on clinical phenotypes. To identify the genes associated with such disorders for diagnostic purposes, geneticists often use high throughput technologies which generate an enormous amount of data on variants whose relevance can be unclear. Besides, analysis and interpretation of high throughput data require gleaning of several web-based resources which can be laborious and time-consuming. To overcome these, we have created a Database for Inherited Ataxia (DINAX), a repository of gene variants from publicly available information.

METHODS

DINAX is implemented as a MySQL relational database using the PHP scripting language. Web interfaces were developed using HTML, CSS, and JavaScript. Variant and phenotype information was collected and manually curated from published literature and primary databases such as OMIM and ClinVar. These were further analyzed to decipher expression and pathway analysis.

RESULTS

DINAX is an inventory of 7166 genomic variants (single nucleotide polymorphisms, deletions, insertions, and translocations) reported till date among the 185 genes associated with different subtypes of inherited ataxia. DINAX implements a dual search methodology for genes and phenotypes linking to ataxia associated genes, variants, and their source. Pathway analysis confirmed their association with ataxia.

CONCLUSION

The database is created to provide a single web source for obtaining information about ataxia related genes. Besides, the database facilitates easy identification of known and reported variants as well as the novel or unreported variants. DINAX is freely available at http://slsdb.manipal.edu/dinax.

A LINE-1 insertion situated in the promoter of IMPG2 is associated with autosomal recessive progressive retinal atrophy in Lhasa Apso dogs

Background

Canine progressive retinal atrophies are a group of hereditary retinal degenerations in dogs characterised by depletion of photoreceptor cells in the retina, which ultimately leads to blindness. PRA in the Lhasa Apso (LA) dog has not previously been clinically characterised or described in the literature, but owners in the UK are advised to have their dog examined through the British Veterinary Association/ Kennel Club/ International Sheep Dog Society (BVA/KC/ISDS) eye scheme annually, and similar schemes that are in operation in other countries. After the exclusion of 25 previously reported canine retinal mutations in LA PRA-affected dogs, we sought to identify the genetic cause of PRA in this breed.

Results

Analysis of whole-exome sequencing data of three PRA-affected LA and three LA without signs of PRA did not identify any exonic or splice site variants, suggesting the causal variant was non-exonic. We subsequently undertook a genome-wide association study (GWAS), which identified a 1.3 Mb disease-associated region on canine chromosome 33, followed by whole-genome sequencing analysis that revealed a long interspersed element-1 (LINE-1) insertion upstream of the IMPG2 gene. IMPG2 has previously been implicated in human retinal disease; however, until now no canine PRAs have been associated with this gene. The identification of this PRA-associated variant has enabled the development of a DNA test for this form of PRA in the breed, here termed PRA4 to distinguish it from other forms of PRA described in other breeds. This test has been used to determine the genotypes of over 900 LA dogs. A large cohort of genotyped dogs was used to estimate the allele frequency as between 0.07–0.1 in the UK LA population.

Conclusions

Through the use of GWAS and subsequent sequencing of a PRA case, we have identified a LINE-1 insertion in the retinal candidate gene IMPG2 that is associated with a form of PRA in the LA dog. Validation of this variant in 447 dogs of 123 breeds determined it was private to LA dogs. We envisage that, over time, the developed DNA test will offer breeders the opportunity to avoid producing dogs affected with this form of PRA.

Genetics of Equine Neurologic Disease

Neurologic disease in horses can be particularly challenging to diagnose and treat. These diseases can result in economic losses, emotional distress to owners, and injury to the horse or handlers. To date, there are 5 neurologic diseases caused by known genetic mutations and several more are suspected to be heritable: lethal white foal syndrome, lavender foal syndrome, cerebellar abiotrophy, occipitoatlantoaxial malformation, and Friesian hydrocephalus. Genetic testing allows owners, breeders, and veterinarians to make informed decisions when selecting dams and sires for breeding or deciding the treatment or prognosis of a neurologic animal.

Calculating the Starting Age for Screening in Relatives of Patients With Colorectal Cancer Based on Data From Large Nationwide Data Sets

BACKGROUND & AIMS

Although colorectal cancer (CRC) screening guidelines acknowledge the need for earlier screening for high-risk individuals, such as those with family history of CRC, there is limited information on how many years earlier these high-risk individuals should be screened; current practice is based on weak evidence. We aimed to provide risk-adapted recommendations on the starting age of CRC screening for individuals with different family histories.

METHODS

We collected data from nationwide family-cancer data sets in Sweden and calculated risk-adapted starting ages of screening for individuals with different family histories of CRC. Family history was defined as a dynamic (time-dependent) variable, allowing for changes during the follow-up period of 1958 through 2015.

RESULTS

During a follow-up of 12,829,251 individuals with genealogy information, 173,796 developed CRC. The 10-year cumulative risk for the average-risk population at age 50 years (the guideline-recommended age for screening) was 0.44%. Individuals with different family histories of CRC attained this equivalent 0.44% risk 3-29 years earlier than their peers in the general population without such a family history. For example, individuals with 1 affected first-degree relative diagnosed before age 45 years reached the corresponding risk level 16 years earlier.

CONCLUSIONS

We determined risk-adapted starting ages of CRC screening for close or distant relatives of patients with CRC, using high quality nationwide data sets. These findings might be used in counselling individuals about the appropriate age to start CRC screening, to optimize screening practice, and to supplement guidelines for CRC screening.

Aniridia and Axenfeld-Rieger Syndrome: Clinical presentations, molecular genetics and current/emerging therapies

Aniridia and Axenfeld-Rieger Syndrome are related, human ocular disorders that are typically inherited in an autosomal dominant manner. Both result from incorrect development of the eye and have, as their most serious consequences, elevated risk to develop the blinding condition glaucoma. This review will focus on describing the clinical presentations of Aniridia and Axenfeld-Rieger Syndrome as well as the molecular genetics and current and emerging therapies used to treat patients.

Outcomes of Endoscopic Surveillance in Individuals With Genetic Predisposition to Hereditary Diffuse Gastric Cancer

BACKGROUND & AIMS

Pathogenic germline variants in CDH1 are associated with risk for diffuse gastric cancer (DGC) and lobular breast cancer. The reported high incidence of DGC and limited sensitivity of endoscopy in detection have prompted recommendation for total prophylactic gastrectomy for carriers of pathogenic or likely pathogenic (PLP) germline variants of CDH1. Multigene panel tests have identified increasing numbers of carriers of PLP variants in CDH1 who lack a family history of DGC. We evaluated outcomes of endoscopic surveillance for carriers of PLP variants of CDH1 with and without family history of DGC.

METHODS

Individuals from 13 families with germline PLP variants of CDH1 were evaluated at the Michigan Medicine Cancer Genetics Clinic from January 1998 through May 2018. Outcomes of esophagogastroduodenoscopy examinations, histopathology analyses, and surgery were compared between individuals with and without a family history of DGC.

RESULTS

We identified 20 carriers of germline CDH1 PLP variants; they underwent endoscopic examinations and/or gastrectomy. None had abnormal findings visible during endoscopy. Signet ring cell carcinoma (SRCC) was detected in 12 of 20 subjects. All but 1 of the carcinomas were tiny and confined to the lamina propria, and 1 was transmural. Seven of 12 subjects who had SRCC reported no diagnoses of DGC in first-degree relatives and did not meet established criteria for CDH1 analysis based on a 3-generation family pedigree.

CONCLUSIONS

More than half of individuals with germlines variants of CDH1 that are PLP had histopathologic evidence for DGC on endoscopy and/or gastrectomy. Family history of DGC and endoscopic findings therefore do not appear to be reliable determinants of risk of SRCC in individuals with genetic predisposition to DGC.

Differential methylation in rare ophthalmic disorders: a systematic review protocol

BACKGROUND

Rare ophthalmic conditions often cause degenerative vision loss which leads to loss of independence, ability to work and ultimately quality life. Differential methylation is an epigenomic marker that is a feature of several diseases, including eye conditions. This review will aim to elucidate the extent to which differential methylation has been identified in rare ophthalmic conditions.

METHODS

A systematic review will be conducted of articles found in the electronic databases MEDLINE, EMBASE, PubMed and Cochrane Library of Systematic Reviews. Grey literature databases GreyLit and OpenGrey will be searched for relevant unpublished sources. Reference lists of articles which meet eligibility criteria will also be screened for forward and reverse citations. Eligibility criteria will include quantitative articles published, before July 2018, written in English and featuring analysis of differential methylation in rare ophthalmic disorders. Studies will be screened firstly by title, abstract and keywords and then by full text for any remaining sources, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data extraction of key characteristics will be completed using customised forms. Methodological rigour will be assessed using customised forms modelled on the Joanna Briggs Institute critical appraisal forms.

DISCUSSION

This systematic review will enable us to identify if differential methylation can be used to characterise rare ophthalmic disease, which could have crucial implications for improving the accuracy and speed of diagnosis, identifying novel therapeutic targets to reduce or prevent vision loss and overall improving understanding of rare ophthalmic disease.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018094231.

Prevalence of Macrothrombocytopenia in Healthy College Students in Western India

Macrothrombocytopenia is being increasingly described across the globe. There is paucity of data on the prevalence of this condition from different parts of India. 10,047 healthy college students from the city of Surat in western India were investigated for macrothrombocytopenia i.e. those with Mean platelet Volume of > 11 fL and platelet count of less than 150 × 10⁹/L. ABO blood groups, complete blood counts, peripheral smear examination and haemoglobinopathy work up was also done. Siblings and parents of the macrothrombocytopenic individuals were also studied when available. Bleeding assessment tool of International society of thrombosis and haemostasis were applied to see if there were excessive bleeding in macrothrombocytropenia patients. One hundred and ninety-six students (1.95%) had asymptomatic macrothrombocytopenia. More female students (P < 0.0001) had this condition and blood group A was under represented (P = 0.019) with this condition. Prevalence of macrothrombocytopenia was not related to ethnic subgroups to which the students belonged to, nor was it linked to presence of any haemoglobinopathy gene. In 38 of the 52, 1st degree relatives studied macrothrombocytopenia was confirmed at least in one of them. Excessive bleeding in none of the individuals with macrothrombocytopenia was noted. Asymptomatic macrothrombocytopenia is rare in western parts of India and affects 1.95% of the healthy population. Females were over represented with this condition raising a suspicion of X linked dominant inheritance. Underrepresentation of blood group A in this condition requires further study.

Noninvasive Immunohistochemical Diagnosis and Novel MUC1 Mutations Causing Autosomal Dominant Tubulointerstitial Kidney Disease

BACKGROUND

Autosomal dominant tubulointerstitial kidney disease caused by mucin-1 gene (MUC1) mutations (ADTKD-MUC1) is characterized by progressive kidney failure. Genetic evaluation for ADTKD-MUC1 specifically tests for a cytosine duplication that creates a unique frameshift protein (MUC1fs). Our goal was to develop immunohistochemical methods to detect the MUC1fs created by the cytosine duplication and, possibly, by other similar frameshift mutations and to identify novel MUC1 mutations in individuals with positive immunohistochemical staining for the MUC1fs protein.

METHODS

We performed MUC1fs immunostaining on urinary cell smears and various tissues from ADTKD-MUC1-positive and -negative controls as well as in individuals from 37 ADTKD families that were negative for mutations in known ADTKD genes. We used novel analytic methods to identify MUC1 frameshift mutations.

RESULTS

After technique refinement, the sensitivity and specificity for MUC1fs immunostaining of urinary cell smears were 94.2% and 88.6%, respectively. Further genetic testing on 17 families with positive MUC1fs immunostaining revealed six families with five novel MUC1 frameshift mutations that all predict production of the identical MUC1fs protein.

CONCLUSIONS

We developed a noninvasive immunohistochemical method to detect MUC1fs that, after further validation, may be useful in the future for diagnostic testing. Production of the MUC1fs protein may be central to the pathogenesis of ADTKD-MUC1.

Advances in Evaluation of Chronic Diarrhea in Infants

Diarrhea is common in infants (children less than 2 years of age), usually acute, and, if chronic, commonly caused by allergies and occasionally by infectious agents. Congenital diarrheas and enteropathies (CODEs) are rare causes of devastating chronic diarrhea in infants. Evaluation of CODEs is a lengthy process and infrequently leads to a clear diagnosis. However, genomic analyses and the development of model systems have increased our understanding of CODE pathogenesis. With these advances, a new diagnostic approach is needed. We propose a revised approach to determine causes of diarrhea in infants, including CODEs, based on stool analysis, histologic features, responses to dietary modifications, and genetic tests. After exclusion of common causes of diarrhea in infants, the evaluation proceeds through analyses of stool characteristics (watery, fatty, or bloody) and histologic features, such as the villus to crypt ratio in intestinal biopsies. Infants with CODEs resulting from defects in digestion, absorption, transport of nutrients and electrolytes, or enteroendocrine cell development or function have normal villi to crypt ratios; defects in enterocyte structure or immune-mediated conditions result in an abnormal villus to crypt ratios and morphology. Whole-exome and genome sequencing in the early stages of evaluation can reduce the time required for a definitive diagnosis of CODEs, or lead to identification of new variants associated with these enteropathies. The functional effects of gene mutations can be analyzed in model systems such as enteroids or induced pluripotent stem cells and are facilitated by recent advances in gene editing procedures. Characterization and investigation of new CODE disorders will improve management of patients and advance our understanding of epithelial cells and other cells in the intestinal mucosa.

Our genes, our selves: hereditary breast cancer and biological citizenship in Norway

The concept 'hereditary breast cancer' is commonly used to delineate a group of people genetically at risk for breast cancer-all of whom also having risk for other cancers. People carrying pathogenic variants of the BRCA1 and BRCA2 genes are often referred to as those having predisposition for 'hereditary breast cancer'. The two genes, however, are when altered, associated with different risks for and dying from breast cancer. The main risk for dying for carriers of both genes is from ovarian cancer. These biological facts are of philosophical interest, because they are the facts underlying the public debate on BRCA1/2 genetic testing as a model for the discussion of how to implement genetic knowledge and technologies in personalized medicine. A contribution to this public debate describing inherited breast cancer as 'biological citizenship' recently printed in Med Health Care and Philos illustrated how fragmented and detached from the biological and socio-political facts this debate sometimes is. We here briefly summarize some of the biological facts and how they are implemented in today's healthcare based on agreed philosophical, ethical and moral principles. The suggestion of a 'biological citizenship' defined by hereditary breast cancer is incorrect and ill-advised. 'Identity politics' focusing hereditary breast cancer patients as a group based on a bundle of ill-defined negative arguments is well known, but is supported neither by scientific nor philosophical arguments. To those born with the genetic variants described, the philosophical rule of not doing harm is violated by unbalanced negative arguments.

Primary hyperfibrinolysis: Facts and fancies

Fibrinolysis is a complex process that controls both hemostasis and thrombosis. The regulation of the fibrinolytic system is mediated through a wide array of cofactors and inhibitors that maintain the hemostatic balance in a delicate equilibrium. As a consequence, disturbances in the fibrinolysis pathway are associated with various disease states, ranging from thrombotic to hemorrhagic clinical phenotypes. In particular, a number of inherited and acquired disorders are associated with an enhanced fibrinolysis leading to a bleeding tendency that in some cases may be life-threatening. Hyperfibrinolysis has been classified into primary and secondary forms but such differentiation, which may have important treatment implications, is still controversial. This narrative review will be focused on inherited and acquired conditions associated with primary hyperfibrinolysis.

Cost Effectiveness of Age-Specific Screening Intervals for People With Family Histories of Colorectal Cancer

BACKGROUND & AIMS

Relative risk of colorectal cancer (CRC) decreases with age among individuals with a family history of CRC. However, no screening recommendations specify less frequent screening with increasing age. We aimed to determine whether such a refinement would be cost effective.

METHODS

We determined the relative risk for CRC for individuals based on age and number of affected first-degree relatives (FDRs) using data from publications. For each number of affected FDRs, we used the Microsimulation Screening Analysis model to estimate costs and effects of colonoscopy screening strategies with different age ranges and intervals. Screening was then optimized sequentially, starting with the youngest age group, and allowing the interval of screening to change at certain ages. Strategies with an incremental cost effectiveness ratio below $100,000 per quality-adjusted life year were considered cost effective.

RESULTS

For people with 1 affected FDR (92% of those with a family history), screening every 3 years beginning at an age of 40 years is most cost effective. If no adenomas are found, the screening interval can gradually be extended to 5 and 7 years, at ages 45 and 55 years, respectively. From a cost-effectiveness perspective, individuals with more affected FDRs should start screening earlier and at shorter intervals. However, frequency can be reduced if no abnormalities are found.

CONCLUSIONS

Using a microsimulation model, we found that for individuals with a family history of CRC, it is cost effective to gradually increase the screening interval if several subsequent screening colonoscopies have negative results and no new cases of CRC are found in family members.

Familial myelodysplastic syndrome/acute myeloid leukemia

A growing number of inherited genetic loci that contribute to myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) development in both children as well as adults are rapidly being identified. In recognition of the clinical impact of this emerging field, the World Health Organization, National Comprehensive Cancer Network, and European LeukemiaNet have all added consideration of inherited predisposition to MDS/AML classification and management. Study of these disorders is providing unique insight into the biology of both sporadic and familial MDS/AML. International collaborative efforts to store germline tissue, document family histories, and pool data are essential to progress in diagnosing and treating both hereditary and sporadic forms of MDS/AML.

Therapeutic Strategies for Hereditary Kidney Cancer

The study of hereditary forms of kidney cancer has vastly increased our understanding of metabolic and genetic pathways involved in the development of both inherited and sporadic kidney cancers. The recognition that diverse molecular events drive different forms of kidney cancers has led to the preclinical and clinical development of specific pathway-directed strategies tailored to treat distinct subgroups of kidney cancer. Here, we describe the molecular mechanisms underlying the pathogenesis of several different types of hereditary renal cancers, review their clinical characteristics, and summarize the treatment strategies for the management of these cancers.

Identification and description of three families with familial Alzheimer disease that segregate variants in the SORL1 gene

Alzheimer disease (AD) is a progressive neurodegenerative disorder and the most common form of dementia. The majority of AD cases are sporadic, while up to 5% are families with an early onset AD (EOAD). Mutations in one of the three genes: amyloid beta precursor protein (APP), presenilin 1 (PSEN1) or presenilin 2 (PSEN2) can be disease causing. However, most EOAD families do not carry mutations in any of these three genes, and candidate genes, such as the sortilin-related receptor 1 (SORL1), have been suggested to be potentially causative. To identify AD causative variants, we performed whole-exome sequencing on five individuals from a family with EOAD and a missense variant, p.Arg1303Cys (c.3907C > T) was identified in SORL1 which segregated with disease and was further characterized with immunohistochemistry on two post mortem autopsy cases from the same family. In a targeted re-sequencing effort on independent index patients from 35 EOAD-families, a second SORL1 variant, c.3050-2A > G, was found which segregated with the disease in 3 affected and was absent in one unaffected family member. The c.3050-2A > G variant is located two nucleotides upstream of exon 22 and was shown to cause exon 22 skipping, resulting in a deletion of amino acids Gly1017- Glu1074 of SORL1. Furthermore, a third SORL1 variant, c.5195G > C, recently identified in a Swedish case control cohort included in the European Early-Onset Dementia (EU EOD) consortium study, was detected in two affected siblings in a third family with familial EOAD. The finding of three SORL1-variants that segregate with disease in three separate families with EOAD supports the involvement of SORL1 in AD pathology. The cause of these rare monogenic forms of EOAD has proven difficult to find and the use of exome and genome sequencing may be a successful route to target them.

Re-emergence of hereditary polyneuropathy in Scandinavian Alaskan malamute dogs-old enemy or new entity? A case series

A homozygous mutation has been identified in the N-myc downstream-regulated gene 1 (NDRG1) in recent cases of polyneuropathy in Alaskan malamute dogs from the Nordic countries and USA. The objective of the present study was to determine if cases diagnosed 30-40 years ago with polyneuropathy in the Alaskan malamute breed in Norway had the same hereditary disease as the recent cases. Fourteen historical cases and 12 recently diagnosed Alaskan malamute dogs with hereditary polyneuropathy, and their parents and littermates (n = 88) were included in this study (total n = 114). After phenotyping of historical and recent cases, NDRG1 genotyping was performed using DNA extracted from archived material from five Norwegian dogs affected by the disease in the late 1970s and 1980s. In addition, pedigrees were analysed. Our study concluded that historical and recent phenotypic polyneuropathy cases were carrying the same NDRG1-mutation. The pedigree analysis showed that all affected Alaskan malamute cases with polyneuropathy could be traced back to one common ancestor of North American origin. By this study, a well-documented example of the silent transmission of recessive disease-causing alleles through many generations is provided, demonstrated by the re-emergence of a phenotypically and genetically uniform entity in the Scandinavian Alaskan malamute population.

Thrombosis in Inherited Fibrinogen Disorders

Although inherited fibrinogen disorders (IFD) are primarily considered to be bleeding disorders, they are associated with a higher thrombotic complication risk than defects in other clotting factors. Managing IFD patients with thrombosis is challenging as anticoagulant treatment may exacerbate the underlying bleeding risk which can be life-threatening. Due to the low prevalence of IFD, there is little information on pathophysiology or optimal treatment of thrombosis in these patients. We searched the literature for cases of thrombosis among IFD patients and identified a total of 128 patient reports. In approximately half of the cases, thromboses were spontaneous, while in the others trauma, surgery, and parturition contributed to the risk. The true mechanism(s) of thrombosis in IFD patients remain to be elucidated. A variety of anticoagulant treatments have been used in the treatment or prevention of thrombosis, sometimes with concurrent fibrinogen replacement therapy. There is no definite evidence that fibrinogen supplementation increases the risk of thrombosis, and it may potentially be effective in the treatment and prevention of both thrombosis and hemorrhage in IFD patients.

Canine Breed-Specific Hepatopathies

Canine hepatopathies, both congenital and acquired, arise from an interaction between genes and environment. Many show increased breed prevalences. This article reviews the current understanding on breed predispositions for congenital portosystemic shunts; microvascular dysplasia and portal vein hypoplasia; ductal plate abnormalities (congenital hepatic fibrosis and Caroli disease); chronic hepatitis (both copper associated and idiopathic); vacuolar hepatopathies; and gallbladder mucocele. Although all these diseases can occur in many breeds and crossbreeds, understanding breed predispositions helps recognition and will guide future research to improve understanding of causes and treatments.

Validation of Recently Proposed Colorectal Cancer Susceptibility Gene Variants in an Analysis of Families and Patients-a Systematic Review

High-throughput sequencing analysis has accelerated searches for genes associated with risk for colorectal cancer (CRC); germline mutations in NTHL1, RPS20, FANCM, FAN1, TP53, BUB1, BUB3, LRP6, and PTPN12 have been recently proposed to increase CRC risk. We attempted to validate the association between variants in these genes and development of CRC in a systematic review of 11 publications, using sequence data from 863 familial CRC cases and 1604 individuals without CRC (controls). All cases were diagnosed at an age of 55 years or younger and did not carry mutations in an established CRC predisposition gene. We found sufficient evidence for NTHL1 to be considered a CRC predisposition gene-members of 3 unrelated Dutch families were homozygous for inactivating p.Gln90Ter mutations; a Canadian woman with polyposis, CRC, and multiple tumors was reported to be heterozygous for the inactivating NTHL1 p.Gln90Ter/c.709+1G>A mutations; and a man with polyposis was reported to carry p.Gln90Ter/p.Gln287Ter; whereas no inactivating homozygous or compound heterozygous mutations were detected in controls. Variants that disrupted RPS20 were detected in a Finnish family with early-onset CRC (p.Val50SerfsTer23), a 39-year old individual with metachronous CRC (p.Leu61GlufsTer11 mutation), and a 41-year-old individual with CRC (missense p.Val54Leu), but not in controls. We therefore found published evidence to support the association between variants in NTHL1 and RPS20 with CRC, but not of other recently reported CRC susceptibility variants. We urge the research community to adopt rigorous statistical and biological approaches coupled with independent replication before making claims of pathogenicity.