Jagged 1 Rescues the Duchenne Muscular Dystrophy Phenotype.

Duchenne muscular dystrophy (DMD), caused by mutations at the dystrophin gene, is the most common form of muscular dystrophy. There is no cure for DMD and current therapeutic approaches to restore dystrophin expression are only partially effective. The absence of dystrophin in muscle results in dysregulation of signaling pathways, which could be targets for disease therapy and drug discovery. Previously, we identified two exceptional Golden Retriever muscular dystrophy (GRMD) dogs that are mildly affected, have functional muscle, and normal lifespan despite the complete absence of dystrophin. Now, our data on linkage, whole-genome sequencing, and transcriptome analyses of these dogs compared to severely affected GRMD and control animals reveals that increased expression of Jagged1 gene, a known regulator of the Notch signaling pathway, is a hallmark of the mild phenotype. Functional analyses demonstrate that Jagged1 overexpression ameliorates the dystrophic phenotype, suggesting that Jagged1 may represent a target for DMD therapy in a dystrophin-independent manner. PAPERCLIP.

Genetically modified ZIKA virus as a microRNA-sensitive oncolytic virus against central nervous system tumors.

Here we introduce a first-in-class microRNA-sensitive oncolytic Zika virus (ZIKV) for virotherapy application against central nervous system (CNS) tumors. The described methodology produced two synthetic modified ZIKV strains that are safe in normal cells, including neural stem cells, while preserving brain tropism and oncolytic effects in tumor cells. The microRNA-sensitive ZIKV introduces genetic modifications in two different virus sites: first, in the established 3'UTR region, and secondly, in the ZIKV protein coding sequence, demonstrating for the first time that the miRNA inhibition systems can be functional outside the UTR RNA sites. The total tumor remission in mice bearing human CNS tumors, including metastatic tumor growth, after intraventricular and systemic modified ZIKV administration, confirms the promise of this virotherapy as a novel agent against brain tumors-highly deadly diseases in urgent need of effective advanced therapies.

MS-Driven Metabolic Alterations Are Recapitulated in iPSC-Derived Astrocytes.

OBJECTIVE: Astrocytes play a significant role in the pathology of multiple sclerosis (MS). Nevertheless, for ethical reasons, most studies in these cells were performed using the Experimental Autoimmune Encephalomyelitis model. As there are significant differences between human and mouse cells, we aimed here to better characterize astrocytes from patients with MS (PwMS), focusing mainly on mitochondrial function and cell metabolism. METHODS: We obtained and characterized induced pluripotent stem cell (iPSC)-derived astrocytes from three PwMS and three unaffected controls, and performed electron microscopy, flow cytometry, cytokine and glutamate measurements, gene expression, in situ respiration, and metabolomics. We validated our findings using a single-nuclei RNA sequencing dataset. RESULTS: We detected several differences in MS astrocytes including: (i) enrichment of genes associated with neurodegeneration, (ii) increased mitochondrial fission, (iii) increased production of superoxide and MS-related proinflammatory chemokines, (iv) impaired uptake and enhanced release of glutamate, (v) increased electron transport capacity and proton leak, in line with the increased oxidative stress, and (vi) a distinct metabolic profile, with a deficiency in amino acid catabolism and increased sphingolipid metabolism, which have already been linked to MS. INTERPRETATION: Here we describe the metabolic profile of iPSC-derived astrocytes from PwMS and validate this model as a very powerful tool to study disease mechanisms and to perform non-invasive drug targeting assays in vitro. Our findings recapitulate several disease features described in patients and provide new mechanistic insights into the metabolic rewiring of astrocytes in MS, which could be targeted in future therapeutic studies. ANN NEUROL 2022;91:652-669.

The 90 plus: longevity and COVID-19 survival.

The world population is getting older and studies aiming to enhance our comprehension of the underlying mechanisms responsible for health span are of utmost interest for longevity and as a measure for health care. In this review, we summarized previous genetic association studies (GWAS) and next-generation sequencing (NGS) of elderly cohorts. We also present the updated hypothesis for the aging process, together with the factors associated with healthy aging. We discuss the relevance of studying older individuals and build databanks to characterize the presence and resistance against late-onset disorders. The identification of about 2 million novel variants in our cohort of more than 1000 elderly Brazilians illustrates the importance of studying highly admixed populations of non-European ancestry. Finally, the ascertainment of nonagenarians and particularly of centenarians who were recovered from COVID-19 or remained asymptomatic opens new avenues of research aiming to enhance our comprehension of biological mechanisms associated with resistance against pathogens.

Global and local ancestry modulate APOE association with Alzheimer's neuropathology and cognitive outcomes in an admixed sample.

Dementia is more prevalent in Blacks than in Whites, likely due to a combination of environmental and biological factors. Paradoxically, clinical studies suggest an attenuation of APOE ε4 risk of dementia in African ancestry (AFR), but a dearth of neuropathological data preclude the interpretation of the biological factors underlying these findings, including the association between APOE ε4 risk and Alzheimer's disease (AD) pathology, the most frequent cause of dementia. We investigated the interaction between African ancestry, AD-related neuropathology, APOE genotype, and functional cognition in a postmortem sample of 400 individuals with a range of AD pathology severity and lack of comorbid neuropathology from a cohort of community-dwelling, admixed Brazilians. Increasing proportions of African ancestry (AFR) correlated with a lower burden of neuritic plaques (NP). However, for individuals with a severe burden of NP and neurofibrillary tangles (NFT), AFR proportion was associated with worse Clinical Dementia Rating sum of boxes (CDR-SOB). Among APOE ε4 carriers, the association between AFR proportion and CDR-SOB disappeared. APOE local ancestry inference of a subset of 309 individuals revealed that, in APOE ε4 noncarriers, non-European APOE background correlated with lower NP burden and, also, worse cognitive outcomes than European APOE when adjusting by NP burden. Finally, APOE ε4 was associated with worse AD neuropathological burden only in a European APOE background. APOE genotype and its association with AD neuropathology and clinical pattern are highly influenced by ancestry, with AFR associated with lower NP burden and attenuated APOE ε4 risk compared to European ancestry.

Challenges and recommendations to increasing the use of exome sequencing and whole genome sequencing for diagnosing rare diseases in Brazil: an expert perspective.

Early diagnosis of genetic rare diseases is an unmet need in Brazil, where an estimated 10-13 million people live with these conditions. Increased use of chromosome microarray assays, exome sequencing, and whole genome sequencing as first-tier testing techniques in suitable indications can shorten the diagnostic odyssey, eliminate unnecessary tests, procedures, and treatments, and lower healthcare expenditures. A selected panel of Brazilian experts in fields related to rare diseases was provided with a series of relevant questions to address before a multi-day conference. Within this conference, each narrative was discussed and edited through numerous rounds of discussion until agreement was achieved. The widespread adoption of exome sequencing and whole genome sequencing in Brazil is limited by various factors: cost and lack of funding, reimbursement, awareness and education, specialist shortages, and policy issues. To reduce the burden of rare diseases and increase early diagnosis, the Brazilian healthcare authorities/government must address the barriers to equitable access to early diagnostic methods for these conditions. Recommendations are provided, including broadening approved testing indications, increasing awareness and education efforts, increasing specialist training opportunities, and ensuring sufficient funding for genetic testing.

Small-fibre Neuropathy in Patients with Familial Amyotrophic Lateral Sclerosis Type 8.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a degenerative disease of the nervous system that primarily affects motor neurons. ALS type 8 (ALS8) is a familiar form with predominant involvement of lower motor neurons, tremor, and slow progression. OBJECTIVE: The aim of this study was to describe sensory involvement in a cohort of ALS8 patients and compare it with the characteristics of sporadic ALS (sALS) patients and controls. METHODS: We compared data from 40 ALS8 and 10 sALS patients assessed by neurological evaluation and electrophysiological study. Skin biopsies were performed in these patients and 12 controls for analysis of intraepidermal nerve fiber (IENF) density by protein gene product 9.5 (PGP 9.5) immunohistochemistry. RESULTS: The ALS8 group was younger than the sALS group at the onset of symptoms (p < 0.05) and had a longer disease evolution (p < 0.01). Sensory abnormalities were evident in 35% of the ALS8 and 30% of the sALS patients by neurological examination, and all ALS patients presented normal sensory nerve action potentials. Despite being similar in the ALS8 and sALS groups, IENF density in the ALS8 group was lower than that in the controls (p < 0.0005). In the ALS8 group, IENF density was significantly lower in patients with impairment of vibratory sensation than in those without this finding (p < 0.05) and in females than in males (p < 0.05). CONCLUSION: Sensory impairment and decreased IENF density are present in ALS8 patients at a frequency and intensity similar to that in the sALS group.

Apolipoprotein E ε2 allele is associated with lower risk of carotid artery obstruction in a population-based autopsy study.

INTRODUCTION: Apolipoprotein E (APOE) ε4 allele has been associated with higher carotid atherosclerosis risk, while the APOE-ε2 seems to decrease this risk. Data from autopsy studies, where carotid arteries can be evaluated in their full extension, is scarce. Therefore, we investigated the association between APOE alleles and direct morphometric measurements of carotid atherosclerosis in an autopsy study with an admixed sample. METHODS: We measured the intima-media thickness (IMT) and stenosis of the common (CCA) and internal carotid (ICA) arteries. The APOE polymorphisms were determined by real-time polymerase chain reaction. Participants were classified into three groups according to the APOE alleles (ε2, ε3, and ε4). We evaluated the association between APOE groups and carotid atherosclerosis using adjusted regression models and included interaction terms of APOE alleles with age, sex, and race. RESULTS: We evaluated 1,850 carotid artery samples from 185 participants (mean age=75±12 years old, 55% female, and 71% White). The APOE-ε2 group (n=17) had a lower carotid obstruction and a lower number of severe stenoses (≥ 70%). Having at least one ε4 allele (n=51) was not associated with carotid atherosclerosis. APOE alleles were also not associated with carotid IMT. Age, sex, and race did not modify these relationships. CONCLUSION: APOE-ε2 carriers had a lower percentage of carotid obstruction and less severe stenosis. APOE-ε4 was not related to a higher risk of carotid atherosclerosis in this cross-sectional population-based autopsy study.

Different gene expression profiles in iPSC-derived motor neurons from ALS8 patients with variable clinical courses suggest mitigating pathways for neurodegeneration.

Amyotrophic lateral sclerosis type 8 (ALS8) is an autosomal dominant form of ALS, which is caused by pathogenic variants in the VAPB gene. Here we investigated five ALS8 patients, classified as 'severe' and 'mild' from a gigantic Brazilian kindred, carrying the same VAPB mutation but displaying different clinical courses. Copy number variation and whole exome sequencing analyses in such individuals ruled out previously described genetic modifiers of pathogenicity. After deriving induced pluripotent stem cells (iPSCs) for each patient (N = 5) and controls (N = 3), motor neurons were differentiated, and high-throughput RNA-Seq gene expression measurements were performed. Functional cell death and oxidative metabolism assays were also carried out in patients' iPSC-derived motor neurons. The degree of cell death and mitochondrial oxidative metabolism were similar in iPSC-derived motor neurons from mild patients and controls and were distinct from those of severe patients. Similar findings were obtained when RNA-Seq from such cells was performed. Overall, 43 genes were upregulated and 66 downregulated in the two mild ALS8 patients when compared with severe ALS8 individuals and controls. Interestingly, significantly enriched pathways found among differentially expressed genes, such as protein translation and protein targeting to the endoplasmic reticulum (ER), are known to be associated with neurodegenerative processes. Taken together, the mitigating mechanisms here presented appear to maintain motor neuron survival by keeping translational activity and protein targeting to the ER in such cells. As ALS8 physiopathology has been associated with proteostasis mechanisms in ER-mitochondria contact sites, such differentially expressed genes appear to relate to the bypass of VAPB deficiency.

Inositol monophosphatase 1 (IMPA1) mutation in intellectual disability patients impairs neurogenesis but not gliogenesis.

A homozygous mutation in the inositol monophosphatase 1 (IMPA1) gene was recently identified in nine individuals with severe intellectual disability (ID) and disruptive behavior. These individuals belong to the same family from Northeastern Brazil, which has 28 consanguineous marriages and 59 genotyped family members. IMPA1 is responsible for the generation of free inositol from de novo biosynthesis and recycling from inositol polyphosphates and participates in the phosphatidylinositol signaling pathway. To understand the role of IMPA1 deficiency in ID, we generated induced pluripotent stem cells (iPSCs) from patients and neurotypical controls and differentiated these into hippocampal dentate gyrus-like neurons and astrocytes. IMPA1-deficient neuronal progenitor cells (NPCs) revealed substantial deficits in proliferation and neurogenic potential. At low passage NPCs (P1 to P3), we observed cell cycle arrest, apoptosis, progressive change to a glial morphology and reduction in neuronal differentiation. These observations were validated by rescuing the phenotype with myo-inositol supplemented media during differentiation of patient-derived iPSCs into neurons and by the reduction of neurogenic potential in control NPCs-expressing shIMPA1. Transcriptome analysis showed that NPCs and neurons derived from ID patients have extensive deregulation of gene expression affecting pathways necessary for neurogenesis and upregulation of gliogenic genes. IMPA1 deficiency did not affect cell cycle progression or survival in iPSCs and glial progenitor cells or astrocyte differentiation. Therefore, this study shows that the IMPA1 mutation specifically affects NPC survival and neuronal differentiation.

Differences in Placental Histology Between Zika Virus-infected Teenagers and Older Women.

In pregnant women, Zika virus (ZIKV) is associated with a congenital syndrome, most frequently involving damage to embryo brain formation and the development of microcephaly. The mechanism(s) by which ZIKV enters the maternal-fetal interface and is transmitted to the fetus remains incompletely determined. We sought to evaluate histologic changes in the placenta of ZIKV-infected pregnant women and to determine if this varied by maternal age. Placental samples were obtained from 66 women, 33 of whom were positive for ZIKV. Histologic evaluations were performed on 4 areas of the placenta: fetal surface, maternal surface, umbilical cord, and membranes. Samples were analyzed by the tissue microarray technique and tested for CD4, CD8, CD20, CD68, FOXP3, and cyclooxygenase-2 expression. Data were evaluated using Fisher exact test. ZIKV infection was more frequent in women less than 18 yr of age (9/11, 81.8%) than in women above 18 yr old (24/55, 43.6%) (P=0.0440). ZIKV detection was associated with neutrophilic chorioamnionitis (P=0.0332) and with septal (P=0.0244) and villous (P=0.0534) calcification. Hofbauer cell hyperplasia (P=0.0260) and cyclooxygenase-2 expression (P=0.0346) were more prevalent in ZIKV-positive women aged 18 yr and below than in the older ZIKV-positive women. ZIKV infection during pregnancy occurs more frequently in adolescents and induces higher rates of damage at the maternal-fetal interface than in older women.

The oldest unvaccinated Covid-19 survivors in South America.

BACKGROUND: Although older adults are at a high risk of severe or critical Covid-19, there are many cases of unvaccinated centenarians who had a silent infection or recovered from mild or moderate Covid-19. We studied three Brazilian supercentenarians, older than 110 years, who survived Covid-19 in 2020 before being vaccinated. RESULTS: Despite their advanced age, humoral immune response analysis showed that these individuals displayed robust levels of IgG and neutralizing antibodies (NAbs) against SARS-CoV-2. Enrichment of plasma proteins and metabolites related to innate immune response and host defense was also observed. None presented autoantibodies (auto-Abs) to type I interferon (IFN). Furthermore, these supercentenarians do not carry rare variants in genes underlying the known inborn errors of immunity, including particular inborn errors of type I IFN. CONCLUSION: These observations suggest that their Covid-19 resilience might be a combination of their genetic background and their innate and adaptive immunity.

Regional differences regarding the occurrence of falls and associated factors in two populations of Brazilian longevous people.

BACKGROUND: Few studies have explored regional asymmetries and their implications for health policies regarding episodes of falls among the population of ≥80 years old in continental and developing countries like Brazil with deep inequalities and sociocultural differences. OBJECTIVE: To evaluate the occurrence of falls and their association with functional capacity and nutritional status in the longest oldest-old living in two municipalities in the Northeast and Southeast of Brazil. METHODS: This is a cross-sectional study, with primary data collection in which were included in the research seniors aged 80 years or more, of both sexes, belonging to two Brazilian municipalities of discrepant socioeconomic aspects. The dependent variable was the occurrence of falls in the last year. The independent variables were grouped into demographic aspects, functional capacity and nutritional status. To identify variables that contribute to the occurrence of falls, the multiple logistic regression model, adopts a significance level of 5%. RESULTS: The sample was composed of 415 oldest-old adults. From the total, 32.3% reported having fallen in the last year, 24.7% in Brejo dos Santos and 37.8% in São Paulo. Among the former population, the mean value of walking speed for those who had falls was 0.27 m/s and for those who had no occurrence of falls was 0.33 m/s; and, among the seniors from São Paulo, the mean values were 0.51 m/s and 0.58 m/s, respectively. Significant correlations between walking speed and falls were verified for both populations, showing that the lower the walking speed, the higher the predisposition to falls. In the final regression model, the occurrence of falls was associated with moderate balance (OR = 5.28; CI: 1.11-25.18) among the longevous people Brejo dos Santos and with very poor functional performance (OR = 16.09; CI:1.46-177.06) among those from São Paulo. CONCLUSION: The results pointed out a lower prevalence of falls in longevous people from Brejo dos Santos than in those from São Paulo and differences regarding the associated factors, showing heterogeneity between the two populations; indicating the need for public policies and effective programmes aimed at preventing falls based on the maintenance or increase of functional capacity.

Psychosocial aspects and support networks associated with disability in two longevous populations in Brazil: a cross-sectional study.

BACKGROUND: Among the oldest old, aged 80 years and over, the prevalence of disability is higher than in other age groups and can be considered a predictor of mortality. OBJECTIVE: To evaluate how psychosocial aspects and support networks influence the disability of these oldest-old individuals, performing a comparison between two longevous populations, one living in one of the poorest regions of Brazil, in the backlands of Paraíba, and another living in one of the largest urban centres in Latin America. METHOD: A cross-sectional study in which 417 oldest-old persons aged 80 years and older were interviewed, with data collected through the "Health, Welfare and Ageing" survey conducted in two Brazilian cities. Disability was assessed by reporting the need for assistance in Activities of Daily Living (ADLs) and Instrumental Activities of Daily Living (IADLs). Bivariate and multiple analyses were performed using R statistical software. RESULTS: Food insufficiency in the first years of life had negative repercussions on the disability of oldest old people living in the northeast. On the other hand, in this region, older people have a higher rate of support and live longer with their peers, which may contribute to reducing feelings of loneliness, depressive symptoms, and worse self-perception of health. In the Southeast, financial constraints, subjective poverty, and unmet needs may favour the development of functional limitations between long-lived people. CONCLUSION: Our findings indicate that regional differences in Brazil may influence the disability of older people aged 80 and older. In northeast Brazil, having no partner may contribute to disability for ADLs and IADLs; while, in the longevous population of São Paulo, having a worse self-rated health may contribute to disability for IADLs.

Nemaline Myopathy in Brazilian Patients: Molecular and Clinical Characterization.

Nemaline myopathy (NM), a structural congenital myopathy, presents a significant clinical and genetic heterogeneity. Here, we compiled molecular and clinical data of 30 Brazilian patients from 25 unrelated families. Next-generation sequencing was able to genetically classify all patients: sixteen families (64%) with mutation in NEB, five (20%) in ACTA1, two (8%) in KLHL40, and one in TPM2 (4%) and TPM3 (4%). In the NEB-related families, 25 different variants, 11 of them novel, were identified; splice site (10/25) and frame shift (9/25) mutations were the most common. Mutation c.24579 G>C was recurrent in three unrelated patients from the same region, suggesting a common ancestor. Clinically, the "typical" form was the more frequent and caused by mutations in the different NM genes. Phenotypic heterogeneity was observed among patients with mutations in the same gene. Respiratory involvement was very common and often out of proportion with limb weakness. Muscle MRI patterns showed variability within the forms and genes, which was related to the severity of the weakness. Considering the high frequency of NEB mutations and the complexity of this gene, NGS tools should be combined with CNV identification, especially in patients with a likely non-identified second mutation.

Haplotypes of single cancer driver genes and their local ancestry in a highly admixed long-lived population of Northeast Brazil.

Admixed populations have not been examined in detail in cancer genetic studies. Here, we inferred the local ancestry of cancer-associated single nucleotide polymorphisms (SNPs) and haplotypes of a highly admixed Brazilian population. SNP array was used to genotype 73 unrelated individuals aged 80-102 years. Local ancestry inference was performed by merging genotyped regions with phase three data from the 1000 Genomes Project Consortium using RFmix. The average ancestry tract length was 9.12-81.71 megabases. Strong linkage disequilibrium was detected in 48 haplotypes containing 35 SNPs in 10 cancer driver genes. All together, 19 risk and eight protective alleles were identified in 23 out of 48 haplotypes. Homozygous individuals were mainly of European ancestry, whereas heterozygotes had at least one Native American and one African ancestry tract. Native-American ancestry for homozygous individuals with risk alleles for HNF1B, CDH1, and BRCA1 was inferred for the first time. Results indicated that analysis of SNP polymorphism in the present admixed population has a high potential to identify new ancestry-associated alleles and haplotypes that modify cancer susceptibility differentially in distinct human populations. Future case-control studies with populations with a complex history of admixture could help elucidate ancestry-associated biological differences in cancer incidence and therapeutic outcomes.

Biased pathogenic assertions of loss of function variants challenge molecular diagnosis of admixed individuals.

Diagnosis of individuals affected by monogenic disorders was significantly improved by next-generation sequencing targeting clinically relevant genes. Whole exomes yield a large number of variants that require several filtering steps, prioritization, and pathogenicity classification. Among the criteria recommended by ACMG, those that rely on population databases critically affect analyses of individuals with underrepresented ancestries. Population-specific allelic frequencies need consideration when characterizing potential deleteriousness of variants. An orthogonal input for classification is annotation of variants previously classified as pathogenic as a criterion that provide supporting evidence widely sourced at ClinVar. We used a whole-genome dataset from a census-based cohort of 1,171 elderly individuals from São Paulo, Brazil, highly admixed, and unaffected by severe monogenic disorders, to investigate if pathogenic assertions in ClinVar are enriched with higher proportions of European ancestry, indicating bias. Potential loss of function (pLOF) variants were filtered from 4,250 genes associated with Mendelian disorders and annotated with ClinVar assertions. Over 1,800 single nucleotide pLOF variants were included, 381 had non-benign assertions. Among carriers (N = 463), average European ancestry was significantly higher than noncarriers (N = 708; p = .011). pLOFs in genomic contexts of non-European local ancestries were nearly three times less likely to have any ClinVar entry (OR = 0.353; p <.0001). Independent pathogenicity assertions are useful for variant classification in molecular diagnosis. However, European overrepresentation of assertions can promote distortions when classifying variants in non-European individuals, even in admixed samples with a relatively high proportion of European ancestry. The investigation and deposit of clinically relevant findings of diverse populations is fundamental improve this scenario.

Admixture/fine-mapping in Brazilians reveals a West African associated potential regulatory variant (rs114066381) with a strong female-specific effect on body mass and fat mass indexes.

BACKGROUND/OBJECTIVES: Admixed populations are a resource to study the global genetic architecture of complex phenotypes, which is critical, considering that non-European populations are severely underrepresented in genomic studies. Here, we study the genetic architecture of BMI in children, young adults, and elderly individuals from the admixed population of Brazil. SUBJECTS/METHODS: Leveraging admixture in Brazilians, whose chromosomes are mosaics of fragments of Native American, European, and African origins, we used genome-wide data to perform admixture mapping/fine-mapping of body mass index (BMI) in three Brazilian population-based cohorts from Northeast (Salvador), Southeast (Bambuí), and South (Pelotas). RESULTS: We found significant associations with African-associated alleles in children from Salvador (PALD1 and ZMIZ1 genes), and in young adults from Pelotas (NOD2 and MTUS2 genes). More importantly, in Pelotas, rs114066381, mapped in a potential regulatory region, is significantly associated only in females (p = 2.76e-06). This variant is rare in Europeans but with frequencies of ~3% in West Africa and has a strong female-specific effect (95% CI: 2.32-5.65 kg/m2 per each A allele). We confirmed this sex-specific association and replicated its strong effect for an adjusted fat mass index in the same Pelotas cohort, and for BMI in another Brazilian cohort from São Paulo (Southeast Brazil). A meta-analysis confirmed the significant association. Remarkably, we observed that while the frequency of rs114066381-A allele ranges from 0.8 to 2.1% in the studied populations, it attains ~9% among women with morbid obesity from Pelotas, São Paulo, and Bambuí. The effect size of rs114066381 is at least five times higher than the FTO SNPs rs9939609 and rs1558902, already emblematic for their high effects. CONCLUSIONS: We identified six candidate SNPs associated with BMI. rs114066381 stands out for its high effect that was replicated and its high frequency in women with morbid obesity. We demonstrate how admixed populations are a source of new relevant phenotype-associated genetic variants.

Biallelic UBE4A loss-of-function variants cause intellectual disability and global developmental delay.

PURPOSE: To identify novel genes associated with intellectual disability (ID) in four unrelated families. METHODS: Here, through exome sequencing and international collaboration, we report eight individuals from four unrelated families of diverse geographic origin with biallelic loss-of-function variants in UBE4A. RESULTS: Eight evaluated individuals presented with syndromic intellectual disability and global developmental delay. Other clinical features included hypotonia, short stature, seizures, and behavior disorder. Characteristic features were appreciated in some individuals but not all; in some cases, features became more apparent with age. We demonstrated that UBE4A loss-of-function variants reduced RNA expression and protein levels in clinical samples. Mice generated to mimic patient-specific Ube4a loss-of-function variant exhibited muscular and neurological/behavioral abnormalities, some of which are suggestive of the clinical abnormalities seen in the affected individuals. CONCLUSION: These data indicate that biallelic loss-of-function variants in UBE4A cause a novel intellectual disability syndrome, suggesting that UBE4A enzyme activity is required for normal development and neurological function.