La importancia de la genética en el estudio de la hipertrigliceridemia / The importance of genetics in the study of hypertriglyceridemia

La hipertrigliceridemia engloba un conjunto de trastornos lipídicos comunes en la práctica clínica, generalmente definidos como una concentración superior a 150mg/dL en ayunas. Existen diversas clasificaciones de la gravedad de la hipertrigliceridemia en función de sus valores séricos, considerándose por norma general moderada cuando los niveles son inferiores a 500mg/dL y severa cuando son mayores de 1.000mg/dL. Su importancia radica en su asociación con otras alteraciones del perfil lipídico, contribuyendo al aumento del riesgo cardiovascular y de pancreatitis aguda, fundamentalmente con concentraciones superiores a 500mg/dL.(AU)

Hypertriglyceridemia encompasses a set of lipid disorders common in clinical practice, generally defined as a fasting concentration above 150mg/dL. There are various classifications of the severity of hypertriglyceridaemia based on serum values, with levels generally considered moderate when below 500mg/dL and severe when above 1000mg/dL. Its importance lies in its association with other alterations in the lipid profile, contributing to increased cardiovascular risk and increased risk of acute pancreatitis, mainly with concentrations above 500mg/dL.(AU)

Sex and Gender in Ageing and Longevity: Highlights From an International Course.

Gender medicine is a multidisciplinary science and represents an important perspective for pathophysiological and clinical studies in the third millennium. Here, it is provided an overview of the topics discussed in a recent course on the Role of Sex and Gender in Ageing and Longevity. The paper highlights three themes discussed in the course, i.e., the interaction of gender/sex with, i) the pathophysiology of age-related diseases; ii), the role of genetics and epigenetics in ageing and longevity and, iii) the immune responses of older people to pathogens, vaccines, autoantigens, and allergens. Although largely unexplored, it is clear that sex and gender are modulators of disease biology and treatment outcomes. It is becoming evident that men and women should no longer be considered as subgroups, but as biologically distinct groups of patients deserving consideration for specific therapeutic approaches.

Identification, validation and quantification of thymoquinone in conjunction with assessment of bioactive possessions and GC-MS profiling of pharmaceutically valuable crop Nigella (Nigella sativa L.) varieties.

Background: Plants have been pivotal in traditional and modern medicine globally, with historical evidence supporting their therapeutic applications. Nigella (Nigella sativa L.) is an annual herbaceous plant of the Ranunculaceae family and is cultivated in the Middle East, Eastern Europe, and Western and Central Asia. The medicinal use of plants dates back thousands of years, documented in ancient writings from various civilizations. Alkaloids, phenolics, saponins, flavonoids, terpenoids, anthraquinones, and tannins found in plants exhibit antioxidant, immunomodulatory, anti-inflammatory, anticancer, antibacterial, and antidiabetic activities. Methodology: This study specifically examines the pharmacological potential of Nigella sativa L., emphasizing thymoquinone-a compound with diverse nutraceutical benefits. The extraction, characterization, and quantification of thymoquinone, alongside other physicochemical parameters, were carried out using ethanol through Soxhlet extraction procedures on five nigella varieties. HPLC analysis was performed to determine the maximum accumulation of thymoquinone in the released variety of the plant and the chemical composition of the seed oil isolated from Nigella sativa L., varieties utilized in the study was determined through GC-MS analysis. Results: The research revealed that the Ajmer nigella-20 variety stands out, exhibiting elevated levels of thymoquinone (0.20 ± 0.07%), antioxidants (76.18 ± 1.78%), and substantial quantities of total phenols (31.85 ± 0.97 mg GAEg-1 seed) and flavonoids (8.150 ± 0.360 mg QE 100 g-1 seed) compared to other varieties. The GC-MS profiling showed the presence of 11 major compounds in the studied varieties, with p-cymene, longifolene, and myristic acid identified as the major chemical compounds present in the oil. Conclusion: The observed variations among Nigella varieties indicate the Ajmer nigella-20 variety as particularly promising for thymoquinone and bioactive compound extraction. This study underscores Nigella's potential as a source of pharmacologically active compounds, highlighting the need for further exploration in therapeutic applications.

Filaggrin loss-of-function variants are associated with atopic dermatitis phenotypes in a diverse, early life prospective cohort.

Loss-of-Function (LoF) variants in the filaggrin (FLG) gene are the strongest known genetic risk factor for atopic dermatitis (AD), but the impact of these variants on AD outcomes is poorly understood. We comprehensively identified genetic variants through targeted region sequencing of FLG in children (n = 438) participating in the Mechanisms of Progression of Atopic Dermatitis to Asthma in Children (MPAACH) cohort. Twenty FLG LoF variants were identified, including one novel variant and nine variants not previously associated with AD. FLG LoF variants were found in 13.6% of the cohort. Among these children, the presence of one or more FLG LoF variants was associated with moderate/severe AD (odds ratio (OR) = 2.00 (95% CI, 1.23-3.68) compared to those with mild AD. Children with FLG LoF variants had a higher SCORAD (SCORing for Atopic Dermatitis (SCORAD); P = 0.012) and higher likelihood of food allergy within the first 2.5 years of life (OR = 2.81, 1.50-5.26). LoF variants were associated with higher transepidermal Water Loss (TEWL) in both lesional (P = 0.018) and non-lesional skin (P = 0.015). Collectively, our study identifies established and novel AD-associated FLG LoF variants and associates FLG LoF with higher TEWL in lesional and non-lesional skin.

Association of the COL4A2 Gene Polymorphisms with Primary Intracerebral Hemorrhage Risk and Outcome in Chinese Han Population.

The relationship of single nucleotide polymorphisms (SNPs) in COL4A2 gene with risk and outcome of primary intracerebral hemorrhage (ICH) in the Chinese Han population remains unclear, which was investigated in this study. Primary ICH patients and non-stroke controls of Chinese Han ethnicity were enrolled. The genotypes of 8 tag-SNPs were determined using a custom-by-design 48-Plex SNPscan Kit. Poor 3-month outcome was defined as modified Rankin Scale score 4-6. Logistic regression was employed to examine association between COL4A2 variants and risk and poor outcome of primary ICH. 323 patients with primary ICH and 376 stroke-free controls were included. Compared to controls, the rs1049931 G and rs1049906 C alleles were associated with increased ICH risk (p = 0.027 and 0.033), and these two allele counts increased this risk after adjustments respectively (additive model: adjusted OR [aOR] 1.41, 95% CI 1.03-1.94, corrected p = 0.043; aOR 1.37, 95% CI 1.01-1.86, corrected p = 0.043). The rs1049931 AG/GG and rs1049906 CT/CC genotypes showed increased susceptibility to non-lobar hemorrhage (aOR 1.63, 95% CI 1.06-2.50, p = 0.025; aOR 1.63, 95% CI 1.07-2.47, p = 0.022). Haplotype analysis revealed an association between rs1049906-rs1049931 haplotype CG and ICH risk (OR 1.36, 95% CI 1.05-1.78, p = 0.021). Regarding clinical outcome, the rs3803230 C allele (dominant model: aOR 1.94, 95% CI 1.04-3.63, p = 0.037) and haplotype AC of rs7990214-rs3803230 (OR 1.98, 95% CI 1.13-3.46, p = 0.015) contributed to 3-month poor outcome. The COL4A2 polymorphisms are associated with an increased risk of primary ICH, mainly non-lobar hemorrhage, and with long-term poor outcome after ICH in Chinese Han population.

Skin Microbial Composition and Genetic Mutation Analysis in Precision Medicine for Epidermolysis Bullosa.

Epidermolysis bullosa (EB) is an inherited skin disease representing a spectrum of rare genetic disorders. These conditions share the common trait that causes fragile skin, resulting in the development of blisters and erosions. The inheritance follows an autosomal pattern, and the array of clinical presentations leads to significant physical suffering, considerable morbidity, and mortality. Despite EB having no cure, effectively managing EB remains an exceptional challenge due to its rarity and complexity, occasionally casting a profound impact on the lives of affected individuals. Considering that EB management requires a multidisciplinary approach, this sometimes worsens the condition of patients with EB due to inappropriate handling. Thus, more appropriate and precise treatment management of EB is essentially needed. Advanced technology in medicine and health comes into the bioinformatics era. Including treatment for skin diseases, omics-based approaches aim to evaluate and handle better disease management and treatment. In this work, we review several approaches regarding the implementation of omics-based technology, including genetics, pathogenic mutation, skin microbiomics, and metagenomics analysis for EB. In addition, we highlight recent updates on the potential of metagenomics analysis in precision medicine for EB.

InDEL instability in two different tumoral tissues and its forensic significance.

There may be cases where malignant tumor samples can be used for forensic DNA profiling studies. STRs are the first systems preferred in forensic science laboratories for identification purposes. However, genetic instability in tumoral tissues causes STR polymorphism to change, leading to erroneous results. On the other hand, insertion/deletion polymorphism (InDels) are used as genetic markers in forensic science, as they have features that make both STR and SNPs preferable. Although previous studies approved that STR instability is observed in many different tumors, there are only a few studies that have displayed the instability of InDels in tumoral tissues before. In this study, it was aimed to determine whether instability is observed in formalin-fixed paraffin-embedded breast and thyroid tumoral tissues at 36plex InDel Panel. A total of 47 cases, 26 of which were diagnosed as breast cancer and 21 as thyroid cancer, were included in the study. In 21 of 26 (80.76%) breast cancers mutational changes were observed, however only 6 of 21 (28.57%) thyroid carcinoma cases displayed instability.Moreover, in these six cases, mutations were detected at only 1 or 2 loci. The most common change in both tissues was loss of heterozygosity. These findings suggest that paraffin embedded tissues of thyroid tumor can be used in cases of forensic genetic identification, however paraffin embedded breast cancer tissues should be examined with care. In conclusion, low InDel mutation rates compared to STR instability, make InDel analysis from paraffin blocks suitable for forensic genetic identification. However, researchers should keep in mind that there may be differences between the profiles of the tumoral tissues taken as reference and the actual case. In addition, by incorporating additional markers such as SNPs and microhaplotypes with low mutation rates into the study alongside Indels, researchers can significantly enhance the discrimination power in identification processes.

A novel LTBP2 gene variant in a Turkish family with juvenile-onset open-angle glaucoma.

BACKGROUND: Juvenile-onset open-angle glaucoma (JOAG) is a rare form of primary open-angle glaucoma (POAG) with an early age of onset before 40 years. Latent transforming growth factor-beta binding protein 2 (LTBP-2) is an extracellular matrix protein with a multi-domain structure and homology to fibrillins. LTBP2 gene variants have been associated with JOAG in a small number of patients. Herein, we report a novel missense variant in the LTBP2 gene in a Turkish family with JOAG. MATERIALS AND METHODS: Blood samples were obtained from three siblings (a 20-year-old woman with JOAG, 26-year-old man with JOAG, and 15-year-old girl with posterior embryotoxon) for genetic analysis. Their father had moderate-severe POAG and the 24-year-old brother had JOAG. The mother and 32-year-old sister were healthy. Although the parents reported no consanguinity, they come from the same village. RESULTS: Clinical exome sequencing analysis of the two siblings with JOAG revealed a novel c.607C>T p.(R203C) (rs777450651) homozygous LTBP2 variant, while the variant was heterozygous in their 15-year-old sister. There were no mutations in the MYOC, CYP1B1, or FBN1 genes. CONCLUSION: We documented a novel missense mutation in the LTBP2 gene leading to a severe form of JOAG with refractory IOP and progressive optic nerve damage, which seems to show autosomal recessive inheritance.

A genetically informed longitudinal study of early-life temperament and childhood aggression.

The present study examined the longitudinal associations between three dimensions of temperament - activity, affect-extraversion, and task orientation - and childhood aggression. Using 131 monozygotic and 173 dizygotic (86 same-sex) twin pairs from the Louisville Twin Study, we elucidated the ages, from 6 to 36 months, at which each temperament dimension began to correlate with aggression at age 7. We employed latent growth modeling to show that developmental increases (i.e., slopes) in activity were positively associated with aggression, whereas increases in affect-extraversion and task orientation were negatively associated with aggression. Genetically informed models revealed that correlations between temperament and aggression were primarily explained by common genetic variance, with nonshared environmental variance accounting for a small proportion of each correlation by 36 months. Genetic variance explained the correlations of the slopes of activity and task orientation with aggression. Nonshared environmental variance accounted for almost half of the correlation between the slopes of affect-extraversion and aggression. Exploratory analyses revealed quantitative sex differences in each temperament-aggression association. By establishing which dimensions of temperament correlate with aggression, as well as when and how they do so, our work informs the development of future child and family interventions for children at highest risk of aggression.

Mitochondrial Haplogroups and Weight Gain After Initiating ART in Patients with HIV.

We studied the association of mitochondrial DNA (mtDNA) haplogroups with weight and body mass index (BMI) gain at 96 weeks in 1,019 treatment-naïve persons with HIV (PWH) who initiated first-line antiretroviral therapy (ART) since 2014. The mean increase in weight and BMI over the study period was 2.90 Kg and 0.98 Kg/m2, respectively. We found a significant adjusted association between the major UK mtDNA haplogroup and lower weight and BMI increase at 96 weeks after ART initiation. Our findings reveal a potential role for mitochondrial genetics in the complex phenomenon of weight gain after initial ART in PWH.

Simplified detection of genetic background admixture using artificial intelligence.

Admixture refers to the mixing of genetic ancestry from different populations. Admixture is important for genomic medicine because it can affect how an individual responds to certain medications, how they metabolize drugs, and susceptibility to certain diseases. For example, some genetic variants associated with drug metabolism and response may be more common in certain populations, and individuals with admixed ancestry may have a different frequency of these variants than individuals from the ancestral populations. Understanding the patterns of admixture in a population can also help researchers identify new genetic variants associated with diseases or traits and develop more personalized and targeted treatments. In this study, we compared and classified the known and self-reported genetic backgrounds from 1000 Genomes Project and admixed samples from GTEx projects using supervised, unsupervised and statistical classification methodologies. We developed a novel tool called Admix-AI that uses a one-dimensional convolutional neural network to understand and classify admixed genetic backgrounds using 213 DNA-marker based genetic background labels. Admix-AI can be used to discover admixed proportions in samples and ultimately aid personalized genomic medicine by identifying specific biomarker systems. We compared Admix-AI to the existing admixture categorization software and found our tool to be computationally faster with 2× speedup and streamlined usage. Admix-AI is available as open-source code under GPL version 3.0 license at https://github.com/rpauly/Admix-AI.

The potential influence of genome-wide adaptive divergence on conservation translocation outcome in an isolated greater sage-grouse population.

Conservation translocations are an important conservation tool commonly employed to augment declining or reestablish extirpated populations. One goal of augmentation is to increase genetic diversity and reduce the risk of inbreeding depression (i.e., genetic rescue). However, introducing individuals from significantly diverged populations risks disrupting coadapted traits and reducing local fitness (i.e., outbreeding depression). Genetic data are increasingly more accessible for wildlife species and can provide unique insight regarding the presence and retention of introduced genetic variation from augmentation as an indicator of effectiveness and adaptive similarity as an indicator of source and recipient population suitability. We used 2 genetic data sets to evaluate augmentation of isolated populations of greater sage-grouse (Centrocercus urophasianus) in the northwestern region of the species range (Washington, USA) and to retrospectively evaluate adaptive divergence among source and recipient populations. We developed 2 statistical models for microsatellite data to evaluate augmentation outcomes. We used one model to predict genetic diversity after augmentation and compared these predictions with observations of genetic change. We used the second model to quantify the amount of observed reproduction attributed to transplants (proof of population integration). We also characterized genome-wide adaptive divergence among source and recipient populations. Observed genetic diversity (HO = 0.65) was higher in the recipient population than predicted had no augmentation occurred (HO = 0.58) but less than what was predicted by our model (HO = 0.75). The amount of shared genetic variation between the 2 geographically isolated resident populations increased, which is evidence of periodic gene flow previously assumed to be rare. Among candidate adaptive genes associated with elevated fixation index (FST) (143 genes) or local environmental variables (97 and 157 genes for each genotype-environment association method, respectively), we found clusters of genes with related functions that may influence the ability of transplants to use local resources and navigate unfamiliar environments and their reproductive potential, all possible reasons for low genetic retention from augmentation.

Influencia potencial de la divergencia adaptativa a nivel genoma sobre el resultado de la reubicación para conservación en una población aislada de urogallo mayor Resumen Las reubicaciones para conservación son una herramienta importante que se usa con frecuencia para aumentar las poblaciones en declinación o reestablecer las poblaciones erradicadas. Una de las metas de este aumento es incrementar la diversidad genética y reducir el riesgo de depresión endogámica (es decir, rescate genético). Sin embargo, la introducción de individuos de una población con divergencia significativa puede perturbar los rasgos coadaptados y reducir la aptitud local (es decir, depresión exogámica). La información genética es cada vez más accesible para las especies silvestres y puede proporcionar conocimiento único con respecto a la presencia y retención de la variación genética introducida a partir del aumento como un indicador de eficiencia y las similitudes adaptativas como un indicador de la idoneidad de la población de origen y la receptora. Usamos dos conjuntos de datos genéticos para evaluar el aumento de las poblaciones aisladas del urogallo mayor (Centrocercus urophasianus) en la región noroeste de la distribución de la especie (Washington, EUA) y para evaluar de forma retrospectiva la divergencia adaptativa entre la población de origen y la receptora. Desarrollamos dos modelos estadísticos para los datos microsatelitales para así evaluar los resultados del aumento. Usamos un modelo para predecir la diversidad genética después del aumento y comparamos estas predicciones con observaciones del cambio genético. Usamos el segundo modelo para cuantificar el aumento de la reproducción observada atribuida a las reubicaciones (evidencia de la integración poblacional). También caracterizamos la divergencia adaptativa a nivel genoma entre la población de origen y la población receptora. La diversidad genética observada (HO = 0.65) fue mayor de lo que se predijo en la población receptora de no haber ocurrido el aumento (HO = 0.58) pero menor de lo que se predijo en nuestro modelo (HO = 0.75). El aumento de la variación genética compartida entre las dos poblaciones residentes geográficamente aisladas incrementó, lo cual es evidencia de un flujo génico periódico que antes se supuso casi no ocurría. Entre los genes adaptativos candidatos asociados a una FST elevada (143 genes) o a variables ambientales locales (97 y 157 genes para cada método de asociación entre el ambiente y el genotipo, respectivamente) encontramos grupos de genes con funciones relacionadas que pueden influir sobre la habilidad de cada reubicación para usar recursos locales y navegar ambientes desconocidos y su potencial reproductivo, todas posibles razones para la baja retención genética en el aumento.

The society for craniofacial genetics and developmental biology 46th annual meeting.

The Society for Craniofacial Genetics and Developmental Biology (SCGDB) held its 46th Annual Meeting at Cincinnati Children's Hospital Medical Center in Cincinnati, Ohio on October 10th-12th, 2023. On the first day of the meeting, Drs. Sally Moody and Justin Cotney were each honored with the SCGDB Distinguished Scientist Awards for their exceptional contributions to the field of craniofacial biology. The following two days of the meeting featured five sessions that highlighted new discoveries in signaling and genomic mechanisms regulating craniofacial development, human genetics, translational and regenerative approaches, and clinical management of craniofacial differences. Interactive workshops on spatial transcriptomics and scientific communication, as well as a poster session facilitated meaningful interactions among the 122 attendees representing diverse career stages and research backgrounds in developmental biology and genetics, strengthened the SCGDB community.

Prospective cohort study of genomic newborn screening: BabyScreen+ pilot study protocol.

INTRODUCTION: Newborn bloodspot screening (NBS) is a highly successful public health programme that uses biochemical and other assays to screen for severe but treatable childhood-onset conditions. Introducing genomic sequencing into NBS programmes increases the range of detectable conditions but raises practical and ethical issues. Evidence from prospectively ascertained cohorts is required to guide policy and future implementation. This study aims to develop, implement and evaluate a genomic NBS (gNBS) pilot programme. METHODS AND ANALYSIS: The BabyScreen+ study will pilot gNBS in three phases. In the preimplementation phase, study materials, including education resources, decision support and data collection tools, will be designed. Focus groups and key informant interviews will also be undertaken to inform delivery of the study and future gNBS programmes. During the implementation phase, we will prospectively recruit birth parents in Victoria, Australia, to screen 1000 newborns for over 600 severe, treatable, childhood-onset conditions. Clinically accredited whole genome sequencing will be performed following standard NBS using the same sample. High chance results will be returned by genetic healthcare professionals, with follow-on genetic and other confirmatory testing and referral to specialist services as required. The postimplementation phase will evaluate the feasibility of gNBS as the primary aim, and assess ethical, implementation, psychosocial and health economic factors to inform future service delivery. ETHICS AND DISSEMINATION: This project received ethics approval from the Royal Children's Hospital Melbourne Research Ethics Committee: HREC/91500/RCHM-2023, HREC/90929/RCHM-2022 and HREC/91392/RCHM-2022. Findings will be disseminated to policy-makers, and through peer-reviewed journals and conferences.

The genetic landscape of autism spectrum disorder in the Middle Eastern population.

Introduction: Autism spectrum disorder (ASD) is characterized by aberrations in social interaction and communication associated with repetitive behaviors and interests, with strong clinical heterogeneity. Genetic factors play an important role in ASD, but about 75% of ASD cases have an undetermined genetic risk. Methods: We extensively investigated an ASD cohort made of 102 families from the Middle Eastern population of Qatar. First, we investigated the copy number variations (CNV) contribution using genome-wide SNP arrays. Next, we employed Next Generation Sequencing (NGS) to identify de novo or inherited variants contributing to the ASD etiology and its associated comorbid conditions in families with complete trios (affected child and the parents). Results: Our analysis revealed 16 CNV regions located in genomic regions implicated in ASD. The analysis of the 88 ASD cases identified 41 genes in 39 ASD subjects with de novo (n = 24) or inherited variants (n = 22). We identified three novel de novo variants in new candidate genes for ASD (DTX4, ARMC6, and B3GNT3). Also, we have identified 15 de novo variants in genes that were previously implicated in ASD or related neurodevelopmental disorders (PHF21A, WASF1, TCF20, DEAF1, MED13, CREBBP, KDM6B, SMURF1, ADNP, CACNA1G, MYT1L, KIF13B, GRIA2, CHM, and KCNK9). Additionally, we defined eight novel recessive variants (RYR2, DNAH3, TSPYL2, UPF3B KDM5C, LYST, and WNK3), four of which were X-linked. Conclusion: Despite the ASD multifactorial etiology that hinders ASD genetic risk discovery, the number of identified novel or known putative ASD genetic variants was appreciable. Nevertheless, this study represents the first comprehensive characterization of ASD genetic risk in Qatar's Middle Eastern population.

BRCA awareness and testing experience in the UK Jewish population: a qualitative study.

BACKGROUND: 1 in 40 UK Jewish individuals carry a pathogenic variant in BRCA1/BRCA2. Traditional testing criteria miss half of carriers, and so population genetic testing is being piloted for Jewish people in England. There has been no qualitative research into the factors influencing BRCA awareness and testing experience in this group. This study aimed to explore these and inform improvements for the implementation of population genetic testing. METHODS: Qualitative study of UK Jewish adults who have undergone BRCA testing. We conducted one-to-one semistructured interviews via telephone or video call using a predefined topic guide, until sufficient information power was reached. Interviews were audio-recorded, transcribed verbatim and interpreted using applied thematic analysis. RESULTS: 32 individuals were interviewed (28 carriers, 4 non-carriers). We interpreted five themes intersecting across six time points of the testing pathway: (1) individual differences regarding personal/family history of cancer, demographics and personal attitudes/approach; (2) healthcare professionals' support; (3) pathway access and integration; (4) nature of family/partner relationships; and (5) Jewish community factors. Testing was largely triggered by connecting information to a personal/family history of cancer. No participants reported decision regret, although there was huge variation in satisfaction. Suggestions were given around increasing UK Jewish community awareness, making information and support services personally relevant and proactive case management of carriers. CONCLUSIONS: There is a need to improve UK Jewish community BRCA awareness and to highlight personal relevance of testing for individuals without a personal/family history of cancer. Traditional testing criteria caused multiple issues regarding test access and experience. Carriers want information and support services tailored to their individual circumstances.

Phenotypic characterisation of SMAD4 variant carriers.

BACKGROUND: Both hereditary haemorrhagic telangiectasia (HHT) and juvenile polyposis syndrome (JPS) are known to be caused by SMAD4 pathogenic variants, with overlapping symptoms for both disorders in some patients. Additional connective tissue disorders have also been reported. Here, we describe carriers of SMAD4 variants followed in an HHT reference centre to further delineate the phenotype. METHODS: Observational study based on data collected from the Clinical Investigation for the Rendu-Osler Cohort database. RESULTS: Thirty-three participants from 15 families, out of 1114 patients with HHT, had an SMAD4 variant (3%).Regarding HHT, 26 out of 33 participants (88%) had a definite clinical diagnosis based on Curaçao criteria. Complication frequencies were as follows: epistaxis (n=27/33, 82%), cutaneous telangiectases (n=19/33, 58%), pulmonary arteriovenous malformations (n=17/32, 53%), hepatic arteriovenous malformations (AVMs) (n=7/18, 39%), digestive angiodysplasia (n=13/22, 59%). No cerebral AVMs were diagnosed.Regarding juvenile polyposis, 25 out of 31 participants (81%) met the criteria defined by Jass et al for juvenile polyposis syndrome. Seven patients (21%) had a prophylactic gastrectomy due to an extensive gastric polyposis incompatible with endoscopic follow-up, and four patients (13%) developed a digestive cancer.Regarding connective tissue disorders, 20 (61%) had at least one symptom, and 4 (15%) participants who underwent echocardiography had an aortic dilation. CONCLUSION: We describe a large cohort of SMAD4 variant carriers in the context of HHT. Digestive complications are frequent, early and diffuse, justifying endoscopy every 2 years. The HHT phenotype, associating pulmonary and hepatic AVMs, warrants systematic screening. Connective tissue disorders broaden the phenotype associated with SMAD4 gene variants and justify systematic cardiac ultrasound and skeletal complications screening.