Large Multigenerational Family Research Articles

The social health of modern student youth: sociological analysis

The article presents results of sociological analysis of social health of modern student youth. The empirical basis of study was composed with results of monitoring study of student youth carried out by sociological laboratory of the Department of Sociology and Social Technologies. Within a framework of sociological monitoring, were evaluated such components of social health of student youth as relationships with friends and relatives, relationships in student community, inter-ethnic relations in University and region, participation in public life, social well-being, active life position and family practices and values. It is established that modern possibilities of living conditions allow each person to organize one's life-style in such a way as to develop synergetic effect for social health, combining achieved standards of organization of everyday life and fashion for healthy lifestyle. It is namely such synergistic effect can be enhanced and induced in social environment. The main role at that is played by namely large multi-generational family.

The role of GPD1L, a sodium channel interacting gene, in the pathogenesis of Brugada Syndrome.

Brugada Syndrome (BrS) is an inherited arrhythmia syndrome in which mutations in the cardiac sodium channel SCN5A (NaV1.5) account for approximately 20% of cases. Mutations in sodium channel-modifying genes may account for additional BrS cases, though BrS may be polygenic given common SNPs associated with BrS have been identified. Recent analysis, however, has suggested that SCN5A should be regarded as the sole monogenic cause of BrS. We sought to re-assess the genetic underpinnings of BrS in a large mutligenerational family with a putative mutation in GPD1L that affects surface membrane expression of NaV1.5 in vitro. Fine linkage mapping was performed in the family using the Illumina Global Screening Array. Whole exome sequencing of the proband was performed to identify rare variants and mutations, and Sanger sequencing was used to assay previously-reported risk single nucleotide polymorphsims (SNPs) for BrS. Linkage analysis decreased the size of the previously-reported microsatellite linkage region to approximately 3 Mb. GPD1L-A280V was the only coding non-synonymous variation present at less than 1% allele frequency in the proband within the linkage region. No rare non-synonymous variants were present outside the linkage area in affected individuals in genes associated with BrS. Risk SNPs known to predispose to BrS were overrepresented in affected members of the family. Together, our data suggest GPD1L-A280V remains the most likely cause of BrS in this large multigenerational family. While care should be taken in interpreting variant pathogenicity given the genetic uncertainty of BrS, our data support inclusion of other putative BrS genes in clinical genetic panels.

Bradycardia in a long QT type 2 family: coinciding KCNH2 and HCN4 variants

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): the Dutch Research Council: NWO Talent Scheme Background A large multigenerational family harboring a pathogenic KCNH2 variant (L69P) was identified. This gene encodes the hERG channel, responsible for the cardiac rapid delayed rectifier K+ current (IKr). Pathogenic variants in KCNH2 can cause Long QT syndrome type 2 (LQTS2). Interestingly, in addition to LQTS2 we observed a high incidence of bradycardia in this family. Bradycardia is a known feature of some types of LQTS. However, evidence of bradycardia in LQTS2 is limited to a few sporadic cases. Purpose This study aims to identify the genetic variants and biophysiological changes in ion channel function, explanatory of the phenotypes LQTS2 and bradycardia. Methods An overview of the phenotype and genetic information of the index and family members was generated , including symptoms and electrocardiogram (ECG) parameters. QTc was calculated using Bazetts’ correction. Segregation of the identified genetic variants with LQTS and bradycardia were determined by LOD score. Biophysiological properties of the encoded ion channels was measured by manual whole-cell patch-clamp experiments. Results On the basis of linkage analysis, the pathogenic variant KCNH2-p.L69P was found to be unrelated to the bradycardia. Therefore, Sanger sequencing of HCN4, encoding the channel responsible for the hyperpolarization-activated current (If), an important current for sinoatrial node automaticity, was performed. We identified the HCN4-p.R666W variant in multiple family members, which co-segregated with bradycardia (LOD-score 3.2). Patients carrying both variants had more severe phenotypes than carriers of a single variant. Patch-clamp experiments in HEK293A-cells expressing wild type, or KCNH2-p.L69P show a reduced current density, and an altered time component of the fast deactivation, explaining the observed LQTS2. Functional assays of HCN4-p.R666W will elucidate the biophysiological changes possibly underlying the bradycardia. Conclusion we present a large multigenerational family that harbors a likely pathogenic variant in HCN4 in conjunction with a pathogenic variant of KCNH2. Double carriers were more affected than single carriers, arguing for continued alertness and deep phenotyping even in families with known pathogenic variants. Furthermore, we identified functional changes in the kinetics of the hERG channel encoded by KCNH2-p.L69P, elucidating the molecular mechanism underlying LQTS2 in this family.

A conserved NR5A1-responsive enhancer regulates SRY in testis-determination

The Y-linked SRY gene initiates mammalian testis-determination. However, how the expression of SRY is regulated remains elusive. Here, we demonstrate that a conserved steroidogenic factor-1 (SF-1)/NR5A1 binding enhancer is required for appropriate SRY expression to initiate testis-determination in humans. Comparative sequence analysis of SRY 5’ regions in mammals identified an evolutionary conserved SF-1/NR5A1-binding motif within a 250 bp region of open chromatin located 5 kilobases upstream of the SRY transcription start site. Genomic analysis of 46,XY individuals with disrupted testis-determination, including a large multigenerational family, identified unique single-base substitutions of highly conserved residues within the SF-1/NR5A1-binding element. In silico modelling and in vitro assays demonstrate the enhancer properties of the NR5A1 motif. Deletion of this hemizygous element by genome-editing, in a novel in vitro cellular model recapitulating human Sertoli cell formation, resulted in a significant reduction in expression of SRY. Therefore, human NR5A1 acts as a regulatory switch between testis and ovary development by upregulating SRY expression, a role that may predate the eutherian radiation. We show that disruption of an enhancer can phenocopy variants in the coding regions of SRY that cause human testis dysgenesis. Since disease causing variants in enhancers are currently rare, the regulation of gene expression in testis-determination offers a paradigm to define enhancer activity in a key developmental process.

Modeling TCIRG1 Neutropenia By Utilizing Patient Derived Induced Pluripotent Stem Cells

Background: Severe congenital neutropenia (SCN) is a hereditary hematopoietic disorder characterized by recurrent infections and leukemic transformation. We previously identified a novel heterozygous missense mutation (R736S) in TCIRG1 causing SCN in a large multigenerational family (PMID: 24753205). We also identified a statistically significant correlation in individuals with lower ANC with rare missense variants in TCIRG1 in a large cohort of population-based genome screening (PMID: 27229898). Recently, we have discovered another TCIRG1 heterozygousvariant: R736C in two unrelated families with congenital neutropenia. Independently, Shinwari et al identified a novel TCIRG1 mutation, V52L, which was correlated with the neutropenic phenotype (PMID: 35573728). Homozygous mutations of TCIRG1 are causing autosomal recessive osteopetrosis (ARO), which is characterized by osteopetrosis and secondary hematological and neurological abnormalities. The Genome Aggregation Database (gnomAD) has no data about TCIRG1 R736S and R736C variants accruing in the healthy population. This is in contrast of numerous healthy individuals with a various heterozygous variants throughout the TCIRG1 gene. Aims: We aim to generate in-vitro model of TCIRG1 neutropenia by utilizing patient derived induced pluripotent stem cells (iPSCs) and characterize the hematological abnormalities caused by mutant TCIRG1 expression. We also aim to characterize the incidence of TCIRG1-associated neutropenia and the prevalence of TCIRG1 variants by sharing this new information within the scientific community through identifying more cases/families with this disease. Methods: Medical history, differential WBC counts and whole exome sequencing (WES) was used to identify the genetic basis of neutropenia in the family with R736S mutation. The R736C mutation in the new families also were identified by WES of the index cases. Medical history, blood counts and Sanger sequencing identified their affected relatives. iPSC lines of 4 affected individuals from 2 families harboring TCIRG1 R736S and R736C mutations and healthy volunteer were generated using standard methodology. S732F benign heterozygous TCIRG1 variant was generated by utilizing CRISPR/Cas9 knock-In gene editing using a healthy volunteer iPSC line. iPSCs hematopoietic differentiation was achieved by using STEMdiff Hematopoietic Kit. Resultant CD34+ cells were differentiated towards neutrophils using a published protocol (PMID: 35795780). Cell proliferation, survival and differentiation characteristics were measured by automated cell counter and flow cytometry, cell viability staining and surface markers analysis for granulocytic differentiation. Results: The discovery of these families came through the reputation and work of the Severe Congenital Neutropenia International Registry (SCNIR) and the expanding use of WES to identify the causes of hereditary disorders. With the identification of the index cases, we have identified several affected family members in each family. In all three families the severity of neutropenia is variable and correlates with the incidence of recurrent bacterial infections. Myeloid differentiation of CD34+ cells derived from iPSCs of 4 patients from two families with R736S and R736C mutations revealed maturation, survival and proliferation abnormalities compared to volunteer cells and cell line harboring benign S732F heterozygous TCIRG1 mutation. All patient cells had from 2 to 3-fold drop in cell proliferation and cell viability drop by over 70% for the patients with R736S and up to 90% with R736C mutation compared to the controls. The myeloid differentiation in the patients' cells, measured by flow cytometry and assessed by CD66b+/CD14+ and CD11b+/CD15+ markers was impaired by 38% and 23% respectively for the patients with R736S and 43% and 24% for the patients harboring R736C mutation. Conclusions: The pathogenesis of TCIRG1-associated neutropenia is currently unknown. Carriers of pathogenic variants from these families appear to have neutropenia with variable severity. Our preliminary studies show that patient iPSC derived hematopoietic cells closely recapitulate the neutropenic phenotype. Population based genomic studies; careful family histories and WES will identify new patients with this disorder.

Combined genotype of HCRTR2 and CLOCK variants in a large family of cluster headache with familial periodicity phenotype.

Cluster headache (CH) is a debilitating condition with severe and recurrent headaches characterized by circannual and circadian rhythms. A genetic contingent was suggested, and several loci were described in large cohorts. However, no variant associated with CH for multiplex families has been described. The purpose of our study was to examine candidate genes and new genetic variants in a multigenerational family of cluster headaches in which two members have original chronobiological characteristics that we have called the phenomenon of "family periodicity". We performed a whole genome sequencing in four patients in a large multigenerational family of cluster headache to identify additional loci associated with CH. This allowed us to replicate the genomic association of HCRTR2 and CLOCK as candidate genes. In two family members with the same phenotypic circadian pattern (familial periodicity) the association of polymorphism NM_001526.4:c.922G > A was shown in the HCRTR2 gene, and NM_004898.4:c.213T > C in the CLOCK gene. This whole genome sequencing reproduced two genetic risk loci for CH already involved in its pathogenicity. This is the first time that the combination of HCRTR2 and CLOCK gene variants is identified in a multigenerational family of CH with striking periodicity characteristics. Our study supports the hypothesis that the combination of HCRTR2 and CLOCK gene variants can contribute to the risk of cluster headache and offer the prospect of a new area of research on the molecular circadian clock.

FGF9-Associated Multiple Synostoses Syndrome Type 3 in a Multigenerational Family

Multiple synostoses syndrome (OMIM: #186500, #610017, #612961, #617898) is a genetically heterogeneous group of autosomal dominant diseases characterized by abnormal bone unions. The joint fusions frequently involve the hands, feet, elbows or vertebrae. Pathogenic variants in FGF9 have been associated with multiple synostoses syndrome type 3 (SYNS3). So far, only five different missense variants in FGF9 that cause SYNS3 have been reported in 18 affected individuals. Unlike other multiple synostoses syndromes, conductive hearing loss has not been reported in SYNS3. In this report, we describe the clinical and selected radiological findings in a large multigenerational family with a novel missense variant in FGF9: c.430T>C, p.(Trp144Arg). We extend the phenotypic spectrum of SYNS3 by suggesting that cleft palate and conductive hearing loss are part of the syndrome and highlight the high degree of intrafamilial phenotypic variability. These findings should be considered when counseling affected individuals.

Novel TCIRG1 Mutations Causing Congenital Neutropenia

Background: Severe congenital neutropenia (SCN) is a bone marrow failure disorder leading to severe neutropenia related infections and leukemia. More than 30 different genes associated with this disorder have been identified. We previously identified a novel heterozygous missense mutation (R736S) of TCIRG1 as the probable cause for SCN in a large multigenerational family through exome sequencing (Makaryan et al; Hum Mutat. 2014 Jul;35(7):824-7). We also identified a statistically significant correlation of rare missense variants of TCIRG1 with lower ANC in three cohorts from the NHLBI Grand Opportunity Exome Sequencing Project (GO ESP; Rosenthal et al; Genet Epidemiol. 2016 Sep;40(6):470-4). Recently, we have discovered a novel TCIRG1 variant (R736C) at the same position in a new family with congenital neutropenia. TCIRG1 encodes subunit a3, a 116-kD component (OC116) of V-ATPases, vacuolar proton pumps which mediate H+ transport through membranes. Homozygous loss-of-function mutations of TCIRG1 are the most common cause of autosomal recessive osteopetrosis (ARO). Mutations R736S and R736C occur at an amino acid residue critical for proton translocation. There are no reports in the literature of individuals with heterozygous mutations at this locus. This is in contrast to the numerous healthy individuals with various heterozygous variants throughout the TCIRG1 gene. Parents of ARO patients harboring homozygous TCIRG1 mutations are considered healthy with no musculoskeletal or hematopoietic abnormalities. Pathogenesis of TCIRG1-associated neutropenia is largely unknown. Hypothesis: We hypothesize that certain heterozygous TCIRG1 variants, like R736S and R736C, may cause SCN through specific molecular pathways. Methods: Family and medical history, differential WBC counts and whole exome sequencing/Identity by Decent (IBD) analysis were used to identify the genetic basis of neutropenia in the previously reported family. Sanger sequencing was used to confirm the findings of exome sequencing and to identify other affected individuals. The R736C mutation was identified by whole exome sequencing with further site-specific analysis of 35 genes. Affected relatives were identified by Sanger sequencing. The Polyphen 2 online prediction tool was used to predict the impact of both substitutions on TCIRG1 function. Results: Discovery and details of the original family were described in our previous report: (Makaryan et al; Hum Mutat. 2014 Jul;35(7):824-7). The second family was discovered in Taiwan, where the primary physician contacted SCNIR about a young patient with neutropenia who had a novel TCIRG1 mutation. Shortly thereafter, we identified two more affected family members. In both families the severity of recurrent bacterial infections is variable, roughly correlating with the severity of the neutropenia. For example, the grandmother of the index patient in the second family was not aware that she had neutropenia. The novel R736C TCIRG1 variant is located in the same position as the previous R736S variant. Arginine in this position is evolutionary highly conserved and both these substitutions cause a major change in amino acid size and properties. Polyphen-2 analysis predicts the effects of both mutations "probably damaging” (score 1.0). Conclusions: Understanding the genetic, epidemiological and molecular basis of TCIRG1-associated neutropenia is important for improving the diagnosis and treatment of this form of congenital neutropenia. The pathogenesis of TCIRG1-associated neutropenia is unknown. It is very important to emphasize that carriers of pathogenic variants from both families have neutropenia with variable severity. The report of this new family suggests that there may be other patients and families with neutropenia caused by mutations in TCIRG1. Population based genome studies, careful family histories and whole genome/exome sequencing will be highly valuable for identifying and helping new patients with this disorder.

Phenotypic and Genotypic Characterization of Hereditary Angioedema in Saudi Arabia.

Hereditary angioedema (HAE) is a potentially life-threatening autosomal dominant disorder affecting roughly 1:50,000 individuals. It is commonly characterized by swelling of the larynx, gastrointestinal tract, extremities, and skin. There is growing genetic heterogeneity associated with this disease but more than 95% of mutations are found in SERPING1, the gene which encodes complement 1 inhibitor (C1-INH). HAE cohorts from several populations have been published but no large scale study has been reported from the Arab world to date. Here we document the clinical and genetic findings of HAE patients from a single Saudi institution, which is a major referral center at the national level. A total of 51 patients across 17 unrelated families were recruited including two large multi-generational families, of which one contained an in-frame exonic deletion that was resolved through MLPA. Two cases were negative for all the genes we tested (including F12, PLG, ANGPT1, MYOF, KNG1, and HS3ST6). The predominant HAE subtype in our cohort was type I, at 76%. We were able to uncover a mutation in 49 patients (96%). No type III (normal C1-INH) patients were encountered in the clinic, suggesting that this subtype does not play a major role in HAE pathogenesis in Saudi Arabia. Additionally, the existence of four patients with consistently normal complement 4 (C4) levels alongside abnormal C1-INH profiles highlights the utility of dual screening for both proteins in suspected patients.

Genetic predisposition to porto-sinusoidal vascular disorder: A functional genomic-based, multigenerational family study.

Porto-sinusoidal vascular disorder (PSVD) is a group of liver vascular diseases featuring lesions encompassing the portal venules and sinusoids unaccompanied by cirrhosis, irrespective of the presence/absence of portal hypertension. It can occur secondary to coagulation disorders or insult by toxic agents. However, the cause of PSVD remains unknown in most cases. Hereditary cases of PSVD are exceptionally rare, but they are of particular interest and may unveil genetic alterations and molecular mechanisms associated with the disease. We performed genome sequencing of four patients and two healthy individuals of a large multigenerational Lebanese family with PSVD and identified a heterozygous deleterious variant (c.547C>T, p.R183W) of FCH and double SH3 domains 1 ( FCHSD1 ), an uncharacterized gene, in patients. This variant segregated with the disease, and its pattern of inheritance was suggestive of autosomal dominant with variable expressivity. RNA structural modelling of human FCHSD1 suggests that the C-to-T substitution at position 547, corresponding to FCHSD1R183W , may increase both messenger RNA (mRNA) and protein stability and its interaction with MTOR-associated protein, LST8 homolog, a key protein of the mechanistic target of rapamycin (mTOR pathway). These predictions were substantiated by biochemical analyses, which showed that FCHSD1R183W induced high FCHSD1 mRNA stability, overexpression of FCHSD1 protein, and an increase in mTORC1 activation. This human FCHSD1 variant was introduced into mice through CRISPR/Cas9 genome editing. Nine out of the 15 mice carrying the human FCHSD1R183W variant mimicked the phenotype of human PSVD, including splenomegaly and enlarged portal vein. Aberrant FCHSD1 structure and function leads to mTOR pathway overactivation and may cause PSVD.

A novel desmoplakin mutation causes dilated cardiomyopathy with palmoplantar keratoderma as an early clinical sign.

BackgroundPPKs represent a heterogeneous group of disorders with hyperkeratosis of palmar and/or plantar skin. PPK, hair shaft abnormalities, cardiomyopathy and arrhythmias can be caused by mutations in desmosomal genes, e.g. desmoplakin (DSP). PPK should trigger genetic testing to reveal mutations with possible related cardiac disease.ObjectivesTo report a large multigenerational family with a novel DSP mutation associated with early‐onset PPK and adult‐onset cardiomyopathy and arrhythmias.MethodsA custom‐designed in‐house panel of 35 PPK related genes was used to screen mutations in the index patient with focal PPK. The identified DSP mutation was verified by Sanger sequencing. DNA samples from 20 members of the large multigenerational family were sequenced for the DSP mutation. Medical records were reviewed. Clinical dermatological evaluation was performed, including light microscopy of hair samples. Cardiac evaluation included clinical examination, echocardiography, cardiac magnetic resonance imaging (CMR), electrocardiogram (ECG), Holter monitoring and laboratory tests.ResultsWe identified a novel autosomal dominant truncating DSP c.2493delA p.(Glu831Aspfs*33) mutation associated with dilated cardiomyopathy (DCM) with arrhythmia susceptibility and focal PPK as an early cutaneous sign. The mutation was found in nine affected family members, but not in any unaffected members. Onset of dermatological findings preceded cardiac symptoms which were variable and occurred at adult age.ConclusionsWe report a novel truncating DSP mutation causing focal PPK with varying severity and left ventricular dilatation and ventricular extrasystoles. This finding emphasizes the importance of genetic diagnosis in patients with PPK for clinical counselling and management of cardiomyopathies and arrhythmias.

A family study implicates GBE1 in the etiology of autism spectrum disorder.

Autism spectrum disorders (ASD) are neurodevelopmental disorders with an estimated heritability of >60%. Family-based genetic studies of ASD have generally focused on multiple small kindreds, searching for de novo variants of major effect. We hypothesized that molecular genetic analysis of large multiplex families would enable the identification of variants of milder effects. We studied a large multigenerational family of European ancestry with multiple family members affected with ASD or the broader autism phenotype (BAP). We identified a rare heterozygous variant in the gene encoding 1,4-ɑ-glucan branching enzyme 1 (GBE1) that was present in seven of seven individuals with ASD, nine of ten individuals with the BAP, and none of four tested unaffected individuals. We genotyped a community-acquired cohort of 389 individuals with ASD and identified three additional probands. Cascade analysis demonstrated that the variant was present in 11 of 13 individuals with familial ASD/BAP and neither of the two tested unaffected individuals in these three families, also of European ancestry. The variant was not enriched in the combined UK10K ASD cohorts of European ancestry but heterozygous GBE1 deletion was overrepresented in large ASD cohorts, collectively suggesting an association between GBE1 and ASD.

Digenic Inheritance of a FOXC2 Mutation and Two PIEZO1 Mutations Underlies Congenital Lymphedema in a Multigeneration Family

BackgroundThe lymphatic system is essential for maintaining the balance of interstitial fluid in tissues and for returning protein-rich fluids (lymph) to the bloodstream. Congenital lymphatic defects lead to accumulation of lymph in peripheral tissues and body cavities, termed primary lymphedema. To date, only a limited number of individual genes have been identified in association with primary lymphedema. However, variability of age of onset and severity of lymphatic abnormalities within some families suggests that multiple mutations or genes may be responsible, thus hampering efforts to identify individual associated genes. MethodsWhole exome sequencing (WES) was performed in 4 members of a large multigeneration family with highly variable lymphedema and followed by Sanger sequencing for identified mutations in 34 additional family members. Genotypes were correlated with clinical and lymphangioscintigraphic phenotypes. ResultsWES uncovered 2 different mechanotransducer PIEZO1 mutations and one FOXC2 transcription factor mutation in various combinations. Sanger sequencing confirmed the presence/absence of the 3 variants in affected and unaffected family members and co-segregation of one or more variants with disease. Genetic profiles did not clearly correlate with the highly variable severity of lymphatic abnormalities. ConclusionsWES in lymphedema families can uncover unexpected combinations of several lymphedema-associated mutations. These findings provide essential information for genetic counseling and reveal complex gene interactions in lymphatic developmental pathways. These can offer insights into the complex spectrum of clinical and lymphatic lymphedema phenotypes and potential targets for treatment.

SCA2 in the Indian population: Unified haplotype and variable phenotypic patterns in a large case series

BackgroundSpinocerebellar ataxia-2 is one of the most prevalent SCA type across the world and one of the commonest in India. We aimed to characterize SCA2 patients both clinically and genetically (ATXN2-CAG repeats and its haplotypic background). MethodsA total of 436 SCA2 patients were recruited consecutively comprising individuals of multiple ethnicities and two large multigenerational families. A detailed clinical evaluation and genetic analysis for CAG repeat length estimation and two marker based haplotype analysis [rs695871 and rs695872 located 177 bp and 106 bp upstream of CAG sequence in Exon 1 of ATXN2] was performed. ResultsGeneralized limb ataxia and slow saccades were prevalent features in majority of our patients, while hyporeflexia and extrapyramidal features were less commonly observed manifestations. Slow ocular saccades, upper limb ataxia and tremor showed significant associations with age of onset, CAG repeat length and disease duration. We observed a 100% association of C-C haplotype with the expanded ATXN2 repeats. ConclusionThis study represents the largest study of SCA2 Indian patients that highlights the clinico-genetic manifestations and haplotype analysis. A significant proportion of patients have not shown the characteristic slow saccades and hyporeflexia thus indicating the influences of other factors in modulation of the disease which warrants further investigations. The observation of CC haplotype in all our SCA2 patients indicates a common origin across all Indian sub populations and that also indicate a common global founder event in the past.

Illegitimacy and its Effects on Marriage Prospects in Eighteenth and Nineteenth Century Rural England

All births, marriages and deaths that occurred in two rural parishes in south-west England in the period 1754–1914 were examined, using a wide array of source material. Records of individuals were linked together into large multi-generational family groups. There were 4,940 births, of which 319 were illegitimate. For the illegitimate cases, the rates of subsequent marriage of mothers and fathers were determined and compared with those for other people in the same parishes. Being the father of an illegitimate child did not impact the chances of subsequent marriage. Being the mother of an illegitimate child decreased the chances of subsequent marriage but only if the mother was co-resident with her children. Where the mother did not live with the illegitimate child(ren), her chances of marriage were similar to that of other women. Mothers of illegitimate children were more likely to marry their cousins and were less geographically mobile than other mothers.

Infant inhibited temperament in primates predicts adult behavior, is heritable, and is associated with anxiety-relevant genetic variation

An anxious or inhibited temperament (IT) early in life is a major risk factor for the later development of stress-related psychopathology. Starting in infancy, nonhuman primates, like humans, begin to reveal their temperament when exposed to novel situations. Here, in Study 1 we demonstrate this infant IT predicts adult behavior. Specifically, in over 600 monkeys, we found that individuals scored as inhibited during infancy were more likely to refuse treats offered by potentially-threatening human experimenters as adults. In Study 2, using a sample of over 4000 monkeys from a large multi-generational family pedigree, we demonstrate that infant IT is partially heritable. The data revealed infant IT to reflect a co-inherited substrate that manifests across multiple latent variables. Finally, in Study 3 we performed whole-genome sequencing in 106 monkeys to identify IT-associated single-nucleotide variations (SNVs). Results demonstrated a genome-wide significant SNV near CTNNA2, suggesting a molecular target worthy of additional investigation. Moreover, we observed lower p values in genes implicated in human association studies of neuroticism and depression. Together, these data demonstrate the utility of our model of infant inhibited temperament in the rhesus monkey to facilitate discovery of genes that are relevant to the long-term inherited risk to develop anxiety and depressive disorders.

Human Genetic Research in Pakistan: Challenges and Way forward

The 90s ushered in the era of molecular genetics in Pakistan. Our centuries’ old tradition of consanguineous marriages, resulting in the availability of large, inbred families with inherited disorders, proved to be a goldmine for geneticists, working to discover new genes and their functions. A multitude of novel genes with previously unknown functions were discovered through genetic linkage analysis, a technique that compares the segregations of DNA markers in normal and affected family members to pinpoint the region that contains the suspect gene. The first few landmark publications on linkage analysis in genetic diseases, from Pakistan, identified only the regions harboring the suspected disease genes.1,2 As the field advanced, disease causing mutations segregating in affected family members were identified through Sanger DNA sequencing of candidate genes in the linked region. In the last decade, the advent of high throughput techniques such as whole exome analysis and animal disease modeling, functional genomics studies became an integral of part of such genetic studies. In addition, bioinformatics tools were developed for predictive modeling of the effect of mutations on protein structure.
 The analysis of a single large multigenerational family with a genetic disorder could provide the same information that would be obtained from many small nuclear families, as usually found in developed countries. This allowed Pakistani researchers to attract collaborators from Universities around the world. DNA samples of numerous Pakistani families were sent to labs across the world for analysis, many times accompanied by a PhD student who would typically spend around six months working on those families. Universities developed efficient pipelines, whereby students would find families with genetic diseases, extract DNA and carry out linkage analysis and, in some cases, identify the gene mutations using Sanger sequencing. This led to a significant increase in the number of publications on genetics, from Pakistan. However, despite all the good work carried in the country, no credible effort had been made to build national capacity to carry the work beyond initial mutation screening.
 We lack the ability to conduct good quality high through put –omics analysis and animal model studies within the country. There are several reasons for this. Firstly, the cost of such research is prohibitive. While some institutes have invested in next generation sequencing platforms, these machines are largely underutilized due to high cost of consumables. Lack of adequate funding for reagents, required for genomic, transcriptomic and proteomic studies, is a major roadblock. Secondly, the ease in attracting foreign collaborators to carry out the functional studies in their labs, has made many Pakistani researchers complacent, often, they are happy to be co-authors in research papers without having to go through the pains to set up the required laboratory facilities. Lastly, the bureaucratic processes and red tape, especially in public sector Universities, make procurement of chemicals and consumables, tedious and time consuming, resulting in demotivation of researchers and faculty. There is a need to address these issues, if we wish to move towards self-sufficiency in conducting high level functional genomics and stem the flow of biological samples from Pakistan. 
 While genetic studies in Pakistan have resulted in the discovery of many novel genes, the benefit of these studies is yet to trickle down to the patients. The willingness of the affected families to participate in these studies is crucial. Many affected families belong to far flung rural areas and have no understanding of their disease, how it is inherited or the implications of participating in such research. It is unlikely that families participating in these studies have any immediate benefits and they should be informed at the time of recruitment using common language which they are able to understand. The role of Institutional Ethics and Review Boards, for the protection of study participants and their rights, needs to be strengthened. It is important not to abandon these families after sample collection but to relay the results of the study and counsel them regarding their future options.
 Despite the rapid advances in genetic medical knowledge, our population has yet to reap its benefits. A small step in right direction is the Compulsory Blood Test of the Relatives of Thalassemia Patient Bill-2017, which makes it compulsory for couples to get tested before marrying. However, the scarcity of gene testing facilities and healthcare professionals trained in clinical genetics is an impediment to the implementation of this bill in the true spirit. It is becoming imperative to educate our healthcare professionals regarding the application of genetics to medical practice. Clinical genetics and its related competencies need to be recognized as medical specialties in the country, before they can be introduced into mainstream clinical practice to improve health outcomes of our affected families.

Clinical and genomic analysis of a large Chinese family with familial cortical myoclonic tremor with epilepsy and SAMD12 intronic repeat expansion.

ObjectiveOur goal was to perform detailed clinical and genomic analysis of a large multigenerational Chinese family with 21 individuals showing symptoms of Familial Cortical Myoclonic Tremor with Epilepsy (FCMTE) that we have followed for over 20 years.MethodsPatients were subjected to clinical evaluation, routine EEG, and structural magnetic resonance imaging. Whole exome sequencing, repeat‐primed PCR, long‐range PCR, and PacBio sequencing were performed to characterize the disease‐causing mutation in this family.ResultsAll evaluated patients manifested adult‐onset seizures and presented with progressive myoclonic postural tremors starting after the third or fourth decade of life. Seizures typically diminished markedly in frequency with implementation of antiseizure medications but did not completely cease. The electroencephalogram of affected individuals showed generalized or multifocal spikes and slow wave complexes. An expansion of TTTTA motifs with addition of TTTCA motifs in intron 4 of SAMD12 was identified to segregate with the disease phenotype in this family. Furthermore, we found that the mutant allele is unstable and can undergo both contraction and expansion by changes in the number of repeat motifs each time it is passed to the next generation. The size of mutant allele varied from 5 to 5.5 kb with 549‐603 copies of TTTTA and 287‐343 copies of TTTCA repeat motifs in this family.SignificanceOur study provides a detailed description of clinical progression of FCMTE symptoms and its management with antiseizure medications. Our method of repeat analysis by PacBio sequencing of long‐range PCR products does not require high‐quality DNA and hence can be easily applied to other families to elucidate any correlation between the repeat size and phenotypic variables, such as, age of onset, and severity of symptoms.

A homozygous UBA5 pathogenic variant causes a fatal congenital neuropathy

BackgroundUBA5 is the activating enzyme of UFM1 in the ufmylation post-translational modification system. Different neurological phenotypes have been associated with UBA5 pathogenic variants including epilepsy, intellectual disability, movement disorders and...

Robust Screening and Cascade Testing for Fragile X Expansions in a Large Multigenerational Family Identify Many Affected Individuals: An Experience in the Remote Area of Indonesia

Fragile X Syndrome (FXS) is the most common known inherited form of intellectual disability (ID), caused by a CGG repeat expansion of the FMR1 gene. The aimed of the study was to screen FMR1 mutation among the ID population followed by cascade testing in a remote area. A PCR-based method was used to screen FMR1 expanded alleles using dried blood spot cards in Flores Island, one of the very remote areas in East Indonesia. The screening included 130 males and 81 females from three schools of children with ID. The screening identified three individuals with expanded alleles including two full mutation males and one premutation male. No expanded allele was detected in females. A second blood sample for confirmatory diagnosis was done using Southern blot. Cascade testing in a remote area of Indonesia found a multigenerational family with a large number of cases with FXS. FXS screening of ID populations followed by cascade testing in positive FXS family in a remote area with challenging accessibility is recommended.