Like Father like Daughter: Surgical Redo Thoracoabdominal Aneurysm Repairs in a Family With Loeys-Dietz Syndrome

Loeys Dietz Syndrome (LDS) is an autosomal dominant connective tissue disorder resulting from a mutation in the transforming growth factor beta receptor (TGFBR) family of genes. It is commonly associated with the development of aortic aneurysms and dissections. We report the successful open surgical management of thoracoabdominal aneurysms in a father and daughter with Loeys-Dietz Syndrome after failed endovascular repair. The daughter required stent graft explantation, while the stent graft remained in the father. These cases highlight the importance of early genetic testing of both patients and first-degree family members in those with a strong history of aortic disease, even when there is a lack of typical connective tissue disorder associated physical exam findings and open surgical index operations.

Genetic analysis and family screening for dilated cardiomyopathy: a retrospective analysis of the stepwise pedigree approach

AIMS

This study aimed to assess the practicality of using a stepwise pedigree-based approach to differentiate between familial and sporadic Dilated Cardiomyopathy (DCM), while also considering timing of the genetic analysis. The analysis includes an examination of the extent to which complete family investigations were conducted in real-world scenarios as well as the length of the investigation.

METHODS

The stepwise pedigree approach involved conducting a comprehensive family history spanning 3 to 4 generations, reviewing medical records of relatives, and conducting clinical screening using echocardiography and electrocardiogram on first-degree relatives. Familial DCM was diagnosed when at least 2 family members were found to have DCM, and genetic analysis was considered as an option. This study involved a manual review of all DCM investigations conducted at the Centre of Cardiovascular Genetics at Umeå University Hospital, where the stepwise pedigree approach has been employed since 2007.

RESULTS

The investigation process had a mean duration of 643 days (95% CI 560.5-724.9). Of the investigations preformed, 94 (68%) were complete, 12 (9%) were ongoing, and 33 (24%) were prematurely terminated and thus incomplete. At the conclusion of the investigations, 55 cases (43%) were classified as familial DCM, 50 (39%) as sporadic DCM, and 22 (18%) remained unassessed due to incomplete pedigrees. Among the familial cases, genetic verification was achieved in 40%.

CONCLUSION

The stepwise pedigree approach is time consuming, and the investigations are often incomplete which may suggest that a more direct approach to genetic analysis, may be warranted.

A "poly-matter network" conception of biological inheritance

Here we intend to shift the "DNA- and information-centric" conception of biological inheritance, with the accompanying exclusion of any non-DNA matter, to a "poly-matter network" framework which, in addition to DNA, considers the action of other cellular membranous constituents. These cellular structures, in particular organelles and plasma membranes, express "landscapes" of specific topologies at their surfaces, which may become altered in response to certain environmental factors. These so-called "membranous environmental landscapes" (MELs), which replicate by self-organization / autopoiesis rather than self-assembly, are transferred from donor to acceptor cells by various - vesicular and non-vesicular - mechanisms and exert novel features in the acceptor cells. The "DNA-centric" conception may be certainly explanatorily sufficient for the transfer of heritable phenotype variation to acceptor cells following the copying of DNA in donor cells and thereby for the phenomenon of biological inheritance of traits. However, it is not causally sufficient. With the observation of phenotype variation, as initially manifested during bacterial transformation, the impact of environmental factors, such as nutrition and stress, in the differential regulation of gene expression has been widely accepted and resulted in intense efforts to resolve the underlying epigenetic mechanisms. However, these are explained under a conceptual frame where the DNA (and associated proteins) are the only matter of inheritance. In contrast, it is our argumentation that inheritance can only be adequately understood as the transfer of DNA in concert with non-DNA matter in a "poly-matter network" conception. The adequate inclusion of the transfer of non-DNA matter is still a desideratum of future genetic research, which may pave the way for the experimental elucidation not only of how DNA and membrane matter act in concert to enable the inheritance of innate traits, but also whether they interact for that of acquired biological traits. Moreover, the "poly-matter network" conception may open new perspectives for an understanding of the pathogenesis of "common complex" diseases.

Correlation between Circle of Willis configuration and intracranial arterial dolichoectasia, and genetic contributions

OBJECTIVES

Intracranial arterial dolichoectasia (IADE) is characterized by the dilation, elongation, and tortuosity of intracranial arteries. We aimed to investigate the association between variations of the Circle of Willis (COW) and IADE in the general population, as well as estimate the genetic correlation between COW variations and IADE.

METHODS

A total of 981 individuals from a population-based cohort were included. Brain magnetic resonance angiography was performed to assess COW variants and measure the diameters of intracranial arteries. IADE was defined as a total intracranial volume-adjusted diameter ≥ 2 standard deviations. Logistic regression models were used to analyze the association between COW variations and IADE. The heritability and genetic correlation were estimated using genome-wide complex trait analysis (GCTA) based on single nucleotide polymorphism (SNP) array data.

RESULTS

The prevalence of IADE was 6.2 %. Hypoplastic/absent A1 segments were associated with an increase in contralateral ICA diameter (β ± SE, 0.279 ± 0.049; p = 0.001) and a decrease in ipsilateral ICA diameter (β ± SE, -0.300 ± 0.050; p = 0.001). Fetal-type posterior cerebral artery (FTP) was associated with a larger ICA diameter (β ± SE, 0.326 ± 0.048; p = 0.001) and a smaller BA diameter (β ± SE, -0.662 ± 0.043; p = 0.001). FTP revealed a positive genetic correlation with ICA dilation (rG = 0.259 ± 0.175; p = 0.0009) and a negative genetic correlation with BA dilation (rG = -0.192 ± 0.153, p = 0.015).

CONCLUSIONS

There was an association between COW variations and larger intracranial arterial diameters in the general population. Genetic factors may play a role in the development of intracranial arterial dilation and the formation of COW variants.

Positive genetic effect of hypertension family history on stroke: A cross Mendelian randomization study

BACKGROUND

Clinical observational study demonstrated that hypertension is an independent risk factor for stroke. Furthermore, both hypertension and stroke exhibit genetic predispositions. However, the genetic relationship between hypertension and stroke in first-degree relatives remains unclear.

METHOD

The Genetic effects were validated using an across-Mendelian randomization (MR) approach. The Genome-Wide Association Study summary data used in this study were obtained from a publicly available platform. The primary MR effect employed was inverse-variance weighted (IVW), and the other analysis methods included MR-Egger, weighted median, simple mode, and weighted mode. Prior to MR analysis, tests for MR_PRESSO, pleiotropy, and heterogeneity were conducted.

RESULT

The presence of family history of hypertension significantly contributed to the genetic predisposition to various types of stroke, including ischemic stroke, subarachnoid hemorrhage, lacunar stroke, cardioembolic ischemic stroke, small vessel ischemic stroke, and large artery atherosclerosis-related ischemic stroke.

CONCLUSION

Briefly, hypertension in first-degree relatives has a genetic impact on the risk of stroke development. Shared genetic factors may exist between hypertension and stroke.

HLA-B gene methylation and expression in Behçet's syndrome: a potential role of epigenetics in the pathogenesis

OBJECTIVES

The HLA-B51 locus has the strongest association with Behçet's syndrome (BS). The presence of a CpG island in the HLA-B gene led us to examine the role of epigenetic regulation in BS.

METHODS

HLA-B51 genotyping was performed via sequence-specific PCR in 15 index familial BS cases, 17 affected relatives, 26 unaffected relatives, 46 sporadic BS cases, and 41 healthy controls. HLA-B methylation level was determined using the Zymo OneStep qMethyl kit, and HLA-B51 mRNA level was assessed by quantitative real-time PCR in 14 index familial BS cases, 15 affected relatives, 15 unaffected relatives, 11 sporadic BS cases, and 10 healthy controls.

RESULTS

HLA-B51 carrier ratio was 13/15 in index familial cases, 13/17 in affected relatives, 22/26 in unaffected relatives, 8/25 in healthy controls, and 35/47 in sporadic BS cases. HLA-B51 expression level in HLA-B51+ BS cases was 2.2-fold higher than in their unaffected relatives (p=0.0149) and 1.3-fold higher than in healthy controls (p=0.0188), while sporadic BS cases had a 2.7-fold higher level than healthy controls (p=0.0487). HLA-B promoter methylation was significantly lower in HLA-B51+ familial BS cases than in unaffected relatives (0.4-fold, p=0.01), affected relatives (0.36-fold, p=0.0219), and healthy controls (0.34-fold, p=0.0371) and slightly lower in HLA-B51+ sporadic BS cases than in healthy controls (0.71-fold, p=0.2347). There was an inverse correlation between HLA-B promoter methylation and HLA-B51 expression in HLA-B51+ sporadic BS cases (p=0.0164).

CONCLUSIONS

This study indicates epigenetic involvement associated with the HLA-B51 locus in BS, both in familial and sporadic cases. Further studies with larger sample sizes are needed to confirm our results.

Novel heterozygous mutation of CACNA2D1 gene in a Chinese family with arrhythmia

BACKGROUND

Primary electrical disorders (PEDs) are a group of cardiac rhythm abnormalities that occur in the absence of detectable structural heart disease and are a significant cause of sudden cardiac death (SCD). The initiation of cardiac muscle contraction and relaxation is orchestrated by the action potential (AP), generated through ionic changes across the membrane. Mutations in the AP-related gene CACNA2D1 have been identified as a causative factor for PED.

METHODS

We recruited a Chinese family with a history of arrhythmia. The proband has experienced palpitations and chest tightness for over 40 years, with symptoms worsening over the past year. Whole exome sequencing (WES) was used to determine the genetic etiologies in this family.

RESULTS

A novel heterozygous missense mutation (NM_000722.3: c.1685G > C;p.G562A) of CACNA2D1 gene was detected. Genotyping of the proband's parents indicated that the arrhythmia phenotype in the proband was caused by a de novo mutation.

CONCLUSIONS

WES was utilized to explore the genetic etiology in a family with arrhythmia, leading to the identification of a novel mutation in the CACNA2D1 gene. This study not only expands the mutation spectrum of the CACNA2D1 gene but also contributes to genetic counseling and clinical diagnosis for this family.

Progressive Familial Intrahepatic Cholestasis Associated With Ubiquitin-Specific Peptidase 53 Gene Variant Presented with Acute-on-Chronic Liver Failure in Turkish Siblings

Progressive familial intrahepatic cholestasis represents a group of disorders characterized by defective bile excretion, which causes a multitude of clinical symptoms of variable severity and usually begins in childhood. During the past few decades, a number of gene sequence variants have been shown to be associated with progressive familial intrahepatic cholestasis, and new subtypes continue to be discovered. Sequence variants of the ubiquitinspecific peptidase 53 gene have previously been associated with a novel autosomal recessive form of cholestasis with coincident normal or low γ-glutamyl transferase, with mild phenotypes. Here, we present 2 siblings with novel homozygous sequence variants in the ubiquitin-specific peptidase 53 gene with acute-on-chronic liver failure who underwent liver transplant.

Genetic Polymorphisms in Cardiovascular Disease: Effects Across Three Generations Exposed to Radiation from the Semipalatinsk Nuclear Test Site

The population in the areas neighboring the Semipalatinsk Nuclear Test Site (SNTS) in the eastern region of Kazakhstan faces increased cardiovascular disease (CVD) risk. Previous research has not explored gene polymorphisms related to CVD in this population. Therefore, the present study examines the prevalence of six CVD-associated genotypes in three generations exposed to SNTS radiation. The genotyping of ApoE Leu28 → Pro, AGT Met174 → Thr, AGT Met235 → Thr, eNOS T786 → C, PON1 Gln192 → Arg, and EDN 1 Lys198 → Asn was performed using real-time polymerase chain reaction. The present study encompassed a cohort of 218 participants with a familial history of arterial hypertension and/or carotid artery disease spanning at least three generations. The analysis unveiled significant disparities in the prevalence of ApoE Leu28 → Pro, eNOS T786 → C, and PON1 Gln192 → Arg genotypes across different generations. Furthermore, a substantial variation in the distribution of the eNOS T786 → C genotype was observed between individuals of Kazakh and Russian ethnicities. Nevertheless, no significant discrepancies were detected in the frequencies of the investigated genotypes between genders. Further research in this area is warranted to enhance the understanding of the genetic factors contributing to CVD in the population exposed to radiation from the SNTS. Specifically, future studies should broaden the scope of genetic polymorphisms investigated and include representatives of healthy individuals who have not been exposed to radiation as controls.

Recapitulation, Heredity, and Freud's View of Human Nature

There's something strange about Freud's Civilization and its Discontents (1930). Biologically, Freud was a Neo-Lamarckian, who believed in both the modification of organisms through need and the inheritance of acquired characteristics. However, in Civilization, Freud argued that because human nature is immutable, society has dim odds of improving substantially. Lamarckians, of course, rejected that any species-nature is immutable, as species can always be transformed via the inheritance of acquired characteristics. In fact, many of Freud's Viennese contemporaries-such as Wilhelm Reich, Julius Tandler, and Paul Kammerer-took their Lamarckism to license precisely the sorts of radical social projects Freud deemed impossible. Thus the Freud of Civilization helped himself to a rigid view of human nature which, given his associated biological views, he seemingly ought to have rejected. In this paper, I explain this apparent inconsistency, and suggest Freud resolved it in the following way: Freud was not merely a Lamarckian, but also a strong and peculiar kind of recapitulationist, who believed stages of psychological development both recapitulate phylogeny, and "remain with us" throughout both individual lives and future species-history. I suggest Freud's recapitulationism supposed a certain inertia: what occurred in phylogenetic history cannot un-occur, and therefore there are aspects of our nature which we cannot un-acquire. In this way, Freud reached a rigid conception of human nature despite his Lamarckism.

Combination of FLNC and JUP variants causing arrhythmogenic cardiomyopathy in an Iranian family with different clinical features

BACKGROUND

Arrhythmogenic cardiomyopathy (ACM) characterized by progressive myocardial loss and replacement with fibro-fatty tissue is a major cause of sudden cardiac death (SCD). In particular, ACM with predominantly left ventricular involvement, known as arrhythmogenic left ventricular cardiomyopathy (ALVC), has a poor prognosis.

METHODS

The proband underwent whole-exome sequencing (WES) to determine the etiology of ALVC. Family members were then analyzed using PCR and Sanger sequencing. Clinical evaluations including 12-lead ECG, transthoracic echocardiography, and cardiac MRI were performed for all available first-degree relatives.

RESULTS

WES identified two variants in the FLNC (c.G3694A) and JUP (c.G1372A) genes, the combination of which results in ALVC and SCD.

CONCLUSION

The present study comprehensively investigates the involvement of two discovered variants of FLNC and JUP in the pathogenesis of ALVC. More study is necessary to elucidate the genetic factors involved in the etiology of ALVC.

A novel heterozygous variant of the SALL1 gene with atypical Townes-Brocks syndrome phenotypes in Chinese family

Townes-Brocks syndrome (TBS) is an autosomal dominant disorder characterised by the triad of anorectal, thumb, and ear malformations. It may also be accompanied by defects in kidney, heart, eyes, hearing, and feet. TBS has been demonstrated to result from heterozygous variants in the SALL1 gene, which encodes zinc finger protein believed to function as a transcriptional repressor. The clinical characteristics of an atypical TBS phenotype patient from a Chinese family are described, with predominant manifestations including external ear dysplasia, unilateral renal hypoplasia with mild renal dysfunction, and hearing impairment. A novel heterozygous variant c.3060T>A (p.Tyr1020*) in exon 2 of the SALL1 gene was identified in this proband. Pyrosequencing of the complementary DNA of the proband revealed that the variant transcript accounted for 48% of the total transcripts in peripheral leukocytes, indicating that this variant transcript has not undergone nonsense-mediated mRNA decay. This variant c.3060T > A is located at the terminal end of exon 2, proximal to the 3' end of the SALL1 gene, and exerts a relatively minor impact on protein function. We suggest that the atypical TBS phenotype observed in the proband may be attributed to the truncated protein retaining partial SALL1 function.

"Re-evaluation of variants of uncertain significance in patients with hereditary arrhythmogenic disorders"

BACKGROUND

Genetic diagnostics support the diagnosis of hereditary arrhythmogenic diseases, but variants of uncertain significance (VUS) complicate matters, emphasising the need for regular reassessment. Our study aims to reanalyse rare variants in different genes in order to decrease VUS diagnoses and thus improve risk stratification and personalized treatment for patients with arrhythmogenic disorders.

METHODS

Genomic DNA was analysed using Sanger sequencing and next-generation sequencing (NGS). The Data was evaluated using various databases and in silico prediction tools and classified according to current ACMG standards by two independent experts.

RESULTS

We identified 53 VUS in 30 genes, of which 17 variants (32%) were reclassified. 13% each were downgraded to likely benign (LB) and benign (B) and 6% were upgraded to likely pathogenic (LP). Reclassifications mainly occurred among variants initially classified in 2017-2019, with rates ranging from 50 to 60%.

CONCLUSION

The results support the assumption that regular reclassification of VUS is important, as it provides new insights for genetic diagnostics, that benefit patients and guide therapeutic approach.

Clarifying Mendelian vs non-Mendelian inheritance

Gregor Mendel developed the principles of segregation and independent assortment in the mid-1800s based on his detailed analysis of several traits in pea plants. Those principles, now called Mendel's laws, in fact, explain the behavior of genes and alleles during meiosis and are now understood to underlie "Mendelian inheritance" of a wide range of traits and diseases across organisms. When asked to give examples of inheritance that do NOT follow Mendel's laws, in other words, examples of non-Mendelian inheritance, students sometimes list incomplete dominance, codominance, multiple alleles, sex-linked traits, and multigene traits and cite as their sources the Khan Academy, Wikipedia, and other online sites. Against this background, the goals of this Perspective are to (1) explain to students, healthcare workers, and other stakeholders why the examples above, in fact, display Mendelian inheritance, as they obey Mendel's laws of segregation and independent assortment, even though they do not produce classic Mendelian phenotypic ratios and (2) urge individuals with an intimate knowledge of genetic principles to monitor the accuracy of learning resources and work with us and those resources to correct information that is misleading.

[The hereditary vessel disease CADASIL]

Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a hereditary small vessel disease of the brain characterized by progressive white matter lesions, subcortical infarcts, and cognitive decline. This autosomal dominant disorder is caused by mutations in the NOTCH3 gene located on chromosome 19, resulting in the accumulation of granular osmiophilic material within the walls of small arteries and arterioles. Clinically, CADASIL typically manifests in mid-adulthood with recurrent ischemic events, migraine with aura, mood disturbances, and cognitive impairment. Neuroimaging plays a crucial role in the diagnosis of CADASIL, with characteristic findings including white matter hyperintensities particularly in the anterior temporal lobe and external capsule.

Sheep litter size heredity basis using genome-wide selective analysis

Sheep are important herbivorous domestic animal globally, and the Chinese indigenous sheep breed has a multitude of economically significant variations due to the diverse geographical and ecological conditions. In particular, certain native breeds exhibit a visible high litter size phenotype due to the selection pressure of natural and artificial for thousands of years, offering an ideal animal model for investigating sheep's fecundity. In this study, selective signal analysis was performed on public whole-genome sequencing data from 60 sheep across eight breeds to identify candidate genes related to litter size. Results revealed that a total of 34,065,017 single-nucleotide polymorphisms (SNPs) were identified from all sheep, and 65 candidate genes (CDGs) were pinpointed from the top 1% of interacted windows and SNPs between the pairwise fixation index (FST, >0.149543) and cross-population extended haplotype homozygosity (XP-EHH, >0.701551). A total of 41 CDGs (e.g. VRTN, EYA2 and MCPH1) were annotated to 576 GO terms, of which seven terms were directly linked to follicular and embryonic development (e.g. TBXT, BMPR1B, and BMP2). In addition, 73 KEGG pathways were enriched by 21 CDGs (e.g. ENTPD5, ABCD4 and RXFP2), mainly related to Hippo (TCF4, BMPR1B and BMP2), TGF-β (BMPR1B and BMP2), PI3K-Akt (ITGB4, IL4R and PPP2R5A) and Jak-STAT signalling pathways (IL20RA and IL4R). Notably, a series of CDGs was under strong selection in sheep with high litter size traits. These findings result could improve the comprehension of the genetic underpinnings of sheep litter size. Furthermore, it provides valuable CDGS for future molecular breeding.

Genetic correlations between liver fat content, metabolic health, and adiposity distribution in the Fels Longitudinal Study

BACKGROUND AND AIMS

Hepatic steatosis is known to be heritable, but its genetic basis is mostly uncharacterized. Steatosis is associated with metabolic and adiposity features; recent studies hypothesize that shared genetic effects between these traits could account for some of the unexplained heritability. This study aimed to quantify these genetic associations in a family-based sample of non-Hispanic white adults.

METHODS AND RESULTS

704 participants (18-95 years, 55.8% female) from the Fels Longitudinal Study with an MRI assessment of liver fat were included. Quantitative genetic analyses estimated the age- and sex-adjusted heritability of individual traits and the genetic correlations within trait pairs. Mean liver fat was 5.95% (SE = 0.23) and steatosis (liver fat >5.56%) was present in 29.8% of participants. Heritability (h2± SE) of steatosis was 0.72 ± 0.17 (p = 6.80e-6). All other traits including liver enzymes, fasting glucose, HOMA-IR, visceral and subcutaneous adipose tissue (VAT, SAT), body mass index, body fat percent, waist circumference, lipids and blood pressure were also heritable. Significant genetic correlations were found between liver fat and all traits except aspartate aminotransferase (AST), and among most trait pairs. Highest genetic correlations were between liver fat and HOMA-IR (0.85 ± 0.08, p = 1.73e-8), fasting glucose and ALT (0.89 ± 0.26, p = 6.68e-5), and HOMA-IR with: waist circumference (0.81 ± 0.12, p = 3.76e-6), body fat percent (0.78 ± 0.12 p = 2.42e-5) and VAT (0.73 ± 0.07, p = 6.37e-8).

CONCLUSIONS

Common genes may exist between liver fat accumulation, metabolic features and adiposity phenotypes.

Neglected Mendelian causes of stroke in adult Chinese patients who had an ischaemic stroke or transient ischaemic attack

BACKGROUND AND PURPOSE

Multiple factors play important roles in the occurrence and prognosis of stroke. However, the roles of monogenic variants in all-cause ischaemic stroke have not been systematically investigated. We aim to identify underdiagnosed monogenic stroke in an adult ischaemic stroke/transient ischaemic attack (TIA) cohort (the Third China National Stroke Registry, CNSR-III).

METHODS

Targeted next-generation sequencing for 181 genes associated with stroke was conducted on DNA samples from 10 428 patients recruited through CNSR-III. The genetic and clinical data from electronic health records (EHRs) were reviewed for completion of the diagnostic process. We assessed the percentages of individuals with pathogenic or likely pathogenic (P/LP) variants, and the diagnostic yield of pathogenic variants in known monogenic disease genes with associated phenotypes.

RESULTS

In total, 1953 individuals harboured at least one P/LP variant out of 10 428 patients. Then, 792 (7.6%) individuals (comprising 759 individuals harbouring one P/LP variant in one gene, 29 individuals harbouring two or more P/LP variants in different genes and 4 individuals with two P/LP variants in ABCC6) were predicted to be at risk for one or more monogenic diseases based on the inheritance pattern. Finally, 230 of 792 individuals manifested a clinical phenotype in the EHR data to support the diagnosis of stroke with a monogenic cause. The most diagnosed Mendelian cause of stroke in the cohort was cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy. There were no relationships between age or family history and the incidence of first symptomatic monogenic stroke in patients.

CONCLUSION

The rate of monogenic cause of stroke was 2.2% after reviewing the clinical phenotype. Possible reasons that Mendelian causes of stroke may be missed in adult patients who had an ischaemic stroke/TIA include a late onset of stroke symptoms, combination with common vascular risks and the absence of a prominent family history.

Whole-exome sequencing revealed a likely pathogenic variant in NF1 causing neurofibromatosis type I and Arrhythmogenic Cardiomyopathy

BACKGROUND

Neurofibromatosis type I (NF1) is a genetic disorder characterized by the tumor's development in nerve tissue. Complications of NF1 can include pigmented lesions, skin neurofibromas, and heart problems such as cardiomyopathy. In this study, we performed whole-exome sequencing (WES) on an Iranian patient with NF1 to identify the genetic cause of the disease.

METHODS

Following clinical assessment, WES was used to identify genetic variants in a family with a son suffering from NF1. No symptomatic manifestations were observed in other family members. In the studied family, in silico and segregation analysis were applied to survey candidate variants.

RESULTS

Clinical manifestations were consistent with arrhythmogenic cardiomyopathy (ACM). WES detected a likely pathogenic heterozygous missense variant, c.3277G > A:p.Val1093Met, in the NF1 gene, confirmed by PCR and Sanger sequencing. The patient's parents and brother had a normal sequence at this locus.

CONCLUSIONS

Although there is no cure for NF1, genetic tests, such as WES, can detect at-risk asymptomatic family members. Furthermore, cardiac evaluation could also help these patients before heart disease development.

William Boven's 1915 thesis "Similarity and Mendelism in the heredity of dementia praecox and manic-depressive insanity"

Boven published, in 1915, his MD thesis at the University of Lausanne in which he examined 60 3- to 4-generation pedigrees ascertained from admitted patients with dementia praecox (DP) and manic-depressive insanity (MDI). He asked three questions: (i) were DP and MDI hereditary? (ii) were they the same or distinct conditions? and (iii) were they Mendelian disorders? Based on the rarity of environmental precipitants severe enough to cause disorder onset and the pattern of disorders in relatives, Boven concluded that both disorders were inherited. He found that MDI largely ran in families through direct transmission across generations while DP was only common in collateral relatives. Both pedigrees contained a substantial number of "psychopathic" (personality disordered) relatives in which DP and MDI pedigrees typically had, respectively, paranoid, and dysthymic/cyclothymic features. Boven concludes that their inheritance is largely distinct but not exclusive, as some pedigrees contained cases of both disorders. With assistance from Wilhelm Weinberg, Boven applied algebraic models with proband correction to rates of DP and MDI in sibships and found the results inconsistent with Mendelian transmission. His study represents among the first examinations, using "modern" methods, of the familial relationship between DP and MDI and the first published in French.

Stem cell models of inherited arrhythmias

Inherited arrhythmias are a heterogeneous group of conditions that confer risk of sudden death. Many inherited arrhythmias have been linked to pathogenic genetic variants that result in ion channel dysfunction, although current genetic testing panels fail to identify variants in many patients, potentially secondary to their underlying substrates being oligogenic or polygenic. Here we review the current state of knowledge surrounding the cellular mechanisms of inherited arrhythmias generated from stem cell models with a focus on integrating genetic and mechanistic data. The utility and limitations of human induced pluripotent stem cell models in disease modeling and drug development are also explored with a particular focus on examples of pharmacogenetics and precision medicine. We submit that progress in understanding inherited arrhythmias is likely to be made by using human induced pluripotent stem cells to model probable polygenic cases as well as to interrogate the diverse and potentially complex molecular networks implicated by genome-wide association studies.

"At a Glance:" The Role of Diagrammatic Representations in Eugenics Appropriations of the "Infamous Juke Family"

The case of the Juke family is one of the most notable episodes of the history of eugenics in the USA. The Jukes were initially brought to the fore in the 1870s by a famous investigation that aimed at estimating the interplay of heredity and environment in determining the problems of poverty and crime. This inquiry triggered a harsh confrontation between two polar interpretations of the study, an "environmentalist" one and a "hereditarian" one. It was with the later reassessment of the case made by the Eugenics American Office (ERO) in the 1910s that the controversy was considered closed with the victory of the eugenicists' hereditarian stance. As a result, the family was made a living proof of the alleged hereditary nature of crime and pauperism and a case study in support of the eugenicists' plea for the sterilization of people deemed the bearers of hereditary defectiveness. In this article, I explore the role played by pedigrees and other diagrammatic representations in the eugenicists' appropriation of the meaning of the case of the Juke family and the role played by this appropriation in asserting the superiority of the ERO's method of work over rival approaches.