Miopatías RYR1 en la infancia: correlación fenotipo-genotipo e incidencia / RYR1 myopathies in childhood: phenotype-genotype correlation and incidence

Introducción: Las miopatías relacionadas con el receptor de rianodina de tipo 1 (RYR1-RM) constituyen la categoría más frecuente de miopatías congénitas. La introducción de técnicas genéticas ha cambiado el paradigma diagnóstico y sugiere la prioridad de estudios moleculares sobre biopsias. Este estudio busca explorar las características clinicoepidemiológicas de pacientes con variantes del gen RYR1 en un hospital pediátrico de tercer nivel con el objetivo de ampliar la comprensión de la correlación genotipo-fenotipo en las RYR1-RM. Pacientes y métodos: Estudio observacional, descriptivo y transversal, de pacientes menores de 14 años con síntomas miopáticos y variantes potencialmente patógenas del gen RYR1 entre enero de 2013 y diciembre de 2023, considerando variables como sexo, edad, desarrollo motor, variantes genéticas, patrón de herencia y otras manifestaciones. Todas las variables fueron tabuladas frente a la variante genética. Resultados: De los nueve pacientes incluidos, la incidencia estimada fue de aproximadamente 1/10.000 nacidos vivos. La mediana en el momento del diagnóstico fue de 6 años, con una variabilidad fenotípica significativa. Se observaron síntomas comunes, como debilidad y retraso del desarrollo motor. Las variantes genéticas afectaron al gen RYR1 de manera diversa, y hubo cinco variantes previamente no descritas. La biopsia muscular se realizó en cinco pacientes, en dos de ellos de tipo miopatía central core; en uno, multiminicore; en uno, desproporción congénita de fibras; y en otro, de patrón inespecífico. Conclusiones: Las RYR1-MR de nuestra serie ofrecieron variabilidad fenotípica y de afectación, con una incidencia en nuestra área de en torno a 1/10.000 recién nacidos. La mayoría de los casos fueron varones, de variantes missense dominantes. Aportamos cinco variantes genéticas no descritas con anterioridad.(AU)

Introduction: Ryanodine receptor type 1-related myopathies (RYR1-RM) represent the most prevalent category of congenital myopathies. The introduction of genetic techniques has shifted the diagnostic paradigm, suggesting the prioritization of molecular studies over biopsies. This study aims to explore the clinical and epidemiological characteristics of patients with RYR1 gene variants in a tertiary pediatric hospital, intending to enhance the understanding of the genotype-phenotype correlation in RYR1-RM. Patients and methods: An observational, descriptive, and cross-sectional study was conducted on patients under 14 years old with myopathic symptoms and potentially pathogenic RYR1 gene variants from January 2013 to December 2023. Variables such as gender, age, motor development, genetic variants, inheritance pattern, and other manifestations were considered. All variables were tabulated against the genetic variant. Results: Of the nine included patients, the estimated incidence was approximately 1 in 10,000 live births. The median age at diagnosis was six years, with significant phenotypic variability. Common symptoms such as weakness and delayed motor development were observed. Genetic variants affected the RYR1 gene diversely, including five previously undescribed variants. Muscle biopsy was performed in five patients, revealing central core myopathy in two, multiminicore in one, congenital fiber-type disproportion in one, and a nonspecific pattern in another.(AU)

FecB Was Associated with Litter Size and Follows Mendel's Laws of Inheritance When It Transited to Next Generation in Suhu Meat Sheep Breeding Population.

In order to investigate the effect of FecB on litter size and growth and development traits of Suhu meat sheep and the inheritance patterns of FecB between parents and offspring in the population. In this experiment, 2241 sheep from the Suhu meat sheep population were tested for FecB using capillary electrophoresis. We combined the lambing records of 473 ewes, the growth trait records of 881 sheep at both the birth and weaning (2-month-old) stages, and the complete genealogical records of 643 lambs to analysis the distribution of FecB in the Suhu meat sheep breeding population, its effect on litter size of ewes, growth and development of lambs, and the inheritance patterns of FecB. The results showed that there were three genotypes of FecB in the Suhu meat sheep population, namely the AA genotype, AG genotype, and GG genotype. FecB in this population has a moderate polymorphism (0.25 < PIC < 0.5), and deviates from Hardy-Weinberg disequilibrium (p < 0.05). The litter size of GG genotype ewes was significantly higher than that with the AG and AA genotypes (p < 0.01). A Chi-square test showed that the inheritance patterns of FecB follows Mendel's Laws of Inheritance (p > 0.05). An association analysis of different genotypes of FecB with body weight and body size of Suhu meat sheep at birth and weaning revealed that FecB adversely affects the early growth and development of Suhu meat sheep. In summary, FecB can improve the litter size of ewes but it has negative effects on the early growth and survival rate of lambs in sheep. Therefore, FecB test results and feeding management measures should be comprehensively applied to improve the reproductive performance of ewes, the survival rate and production performance of lambs in sheep production, and thus improve the economic benefits of sheep farms.

Macular dystrophies associated with Stargardt-like phenotypes / Distrofias maculares associadas a fenótipos Stargardt-like

ABSTRACT Purpose: Stargardt-like phenotype has been described as associated with pathogenic variants besides the ABCA4 gene. This study aimed to describe four cases with retinal appearance of Stargardt disease phenotypes and unexpected molecular findings. Methods: This report reviewed medical records of four patients with macular dystrophy and clinical features of Stargardt disease. Ophthalmic examination, fundus imaging, and next-generation sequencing were performed to evaluate pathogenic variants related to the phenotypes. Results: Patients presented macular atrophy and pigmentary changes suggesting Stargardt disease. The phenotypes of the two patients were associated with autosomal dominant inheritance pattern genes (RIMS1 and CRX) and in the other two patients were associated with recessive dominant inheritance pattern genes (CRB1 and RDH12) with variants predicted to be pathogenic. Conclusion: Macular dystrophies may have phenotypic similarities to Stargardt-like phenotype associated with other genes besides the classic ones.

RESUMO Objetivo: Fenótipos Stargardt-like já foram asso-ciados a variantes patogênicas no gene ABCA4. O propósito desse estudo é descrever quatro pacientes com achados retinianos semelhantes a doença de Stargardt com resultados moleculares diferentes do esperado. Métodos: Esse relato fez a revisão de prontuários médicos de quatro pacientes com distrofia macular e achados clínicos sugestivos de doença de Stargardt. Foram realizados avaliação oftalmológica, exames de imagens e testes usando next generation sequencing para avaliar variantes patogênicas associadas aos fenótipos dos pacientes. Resultados: Os pacientes apresentavam atrofia macular e alterações pigmentares sugerindo achados clínicos de doença de Stargardt. Dois pacientes foram associados a genes com herança autossômica dominante (RIMS1 e CRX) e dois pacientes foram associados a genes com herança autossômica recessiva (CRB1 e RDH12) com variantes preditoras de serem patogênicas. Conclusão: Distrofias maculares podem ter similaridades fenotípicas com fenótipo de Stargardt-like associados a outros genes além dos classicamente já descritos.

Association of Catechol-O-Methyl-Transferase and Estrogen Receptors polymorphism with Severity of Temporomandibular Disorder in Iranian Patients.

Background: There are many studies which strongly suggest that the pathophysiology of Temporomandibular joint Disorder (TMD) may also be influenced by genetic conditions. The current study was aimed to evaluate the hypothesis that the polymorphism of estrogen receptor genes, estrogen receptor 1 and 2 (ESR1 and ESR2), and the gene Catechol-O-Methyl-Transferase (COMT) could be Predisposing factor for TMD. Methods: In this case-control study, blood sample were taken from 100 TMD diagnosed patients based on Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and 103 healthy individuals as the control group. Tetra ARMS-PCR method was used to amplify and identify COMT rs4680, ESR1 rs1643821, and ESR2 rs1676303 gene polymorphism. Results: ESR1 genotype AA and GA showed significantly increase probability (OR= 4.80, OR=2.98, respectively) of TMD. ESR2 T/T homozygosity was associated with decreased risk for TMD (OR=0.41). The relationship between COMT and TMD was not statistically significant (p>00.05). The relationship between the severity of TMD and ESR1 was significant (p=0.003). According to the inheritance pattern the COMT and ESR1 gene, in the dominant pattern can be susceptible to TMD and in ESR2 gene, in the recessive pattern can be protective to TMD. Conclusion: It seems that SNPs of ESR1 rs1643821 has a susceptible role and ESR2 rs1676303 has a protective role against TMD. Also, we add evidences that various genotype of COMT rs4680 were not statistically different between case and control, but allele A in the dominant inherence pattern can be susceptible to TMD.

Clinical, genetic and biochemical signatures of RBP4-related ocular malformations.

BACKGROUND: The retinoic acid (RA) pathway plays a crucial role in both eye morphogenesis and the visual cycle. Individuals with monoallelic and biallelic pathogenic variants in retinol-binding protein 4 (RBP4), encoding a serum retinol-specific transporter, display variable ocular phenotypes. Although few families have been reported worldwide, recessive inherited variants appear to be associated with retinal degeneration, while individuals with dominantly inherited variants manifest ocular development anomalies, mainly microphthalmia, anophthalmia and coloboma (MAC). METHODS: We report here seven new families (13 patients) with isolated and syndromic MAC harbouring heterozygous RBP4 variants, of whom we performed biochemical analyses. RESULTS: For the first time, malformations that overlap the clinical spectrum of vitamin A deficiency are reported, providing a link with other RA disorders. Our data support two distinct phenotypes, depending on the nature and mode of inheritance of the variants: dominantly inherited, almost exclusively missense, associated with ocular malformations, in contrast to recessive, mainly truncating, associated with retinal degeneration. Moreover, we also confirm the skewed inheritance and impact of maternal RBP4 genotypes on phenotypical expression in dominant forms, suggesting that maternal RBP4 genetic status and content of diet during pregnancy may modify MAC occurrence and severity. Furthermore, we demonstrate that retinol-binding protein blood dosage in patients could provide a biological signature crucial for classifying RBP4 variants. Finally, we propose a novel hypothesis to explain the mechanisms underlying the observed genotype-phenotype correlations in RBP4 mutational spectrum. CONCLUSION: Dominant missense variants in RBP4 are associated with MAC of incomplete penetrance with maternal inheritance through a likely dominant-negative mechanism.

Clinical Characteristics and Genetic Variants of a Large Cohort of Patients with Retinitis Pigmentosa Using Multimodal Imaging and Next Generation Sequencing.

This retrospective study identifies patients with RP at the Inherited Retinal Disease Clinic at the University of Minnesota (UMN)/M Health System who had genetic testing via next generation sequencing. A database was curated to record history and examination, genetic findings, and ocular imaging. Causative pathogenic and likely pathogenic variants were recorded. Disease status was further characterized by ocular coherence tomography (OCT) and fundus autofluorescence (AF). Our study cohort included a total of 199 patients evaluated between 1 May 2015-5 August 2022. The cohort included 151 patients with non-syndromic RP and 48 with syndromic RP. Presenting symptoms included nyctalopia (85.4%) photosensitivity/hemeralopia (60.5%), and decreased color vision (55.8%). On average, 38.9% had visual acuity of worse than 20/80. Ellipsoid zone band width on OCT scan of less than 1500 µm was noted in 73.6%. Ninety-nine percent had fundus autofluorescence (AF) findings of a hypo- or hyper-fluorescent ring within the macula and/or peripheral hypo-AF. Of the 127 subjects who underwent genetic testing, a diagnostic pathogenic and/or likely pathogenic variant was identified in 67 (52.8%) patients-33.3% of syndromic RP and 66.6% of non-syndromic RP patients had a diagnostic gene variant identified. It was found that 23.6% of the cohort had negative genetic testing results or only variants of uncertain significance identified, which were deemed as non-diagnostic. We concluded that patients with RP often present with advanced disease. In our population, next generation sequencing panels identified a genotype consistent with the exam in just over half the patients. Additional work will be needed to identify the underlying genetic etiology for the remainder.

Genetic features and kidney morphological changes in women with X-linked Alport syndrome.

BACKGROUND: X-linked Alport syndrome (XLAS) caused by COL4A5 pathogenic variants usually has heterogeneous phenotypes in female patients. The genetic characteristics and glomerular basement membrane (GBM) morphological changes in women with XLAS need to been further investigated. METHODS: A total of 83 women and 187 men with causative COL4A5 variants were enrolled for comparative analysis. RESULTS: Women were more frequently carrying de novo COL4A5 variants compared with men (47% vs 8%, p=0.001). The clinical manifestations in women were variable, and no genotype-phenotype correlation was observed. Coinherited podocyte-related genes, including TRPC6, TBC1D8B, INF2 and MYH9, were identified in two women and five men, and the modifying effects of coinherited genes contributed to the heterogeneous phenotypes in these patients. X-chromosome inactivation (XCI) analysis of 16 women showed that 25% were skewed XCI. One patient preferentially expressing the mutant COL4A5 gene developed moderate proteinuria, and two patients preferentially expressing the wild-type COL4A5 gene presented with haematuria only. GBM ultrastructural evaluation demonstrated that the degree of GBM lesions was associated with the decline in kidney function for both genders, but more severe GBM changes were found in men compared with women. CONCLUSIONS: The high frequency of de novo variants carried by women indicates that the lack of family history tends to make them susceptible to be underdiagnosed. Coinherited podocyte-related genes are potential contributors to the heterogeneous phenotype of some women. Furthermore, the association between the degree of GBM lesions and decline in kidney function is valuable in evaluating the prognosis for patients with XLAS.

Heritability of temperature-mediated flower size plasticity in Arabidopsis thaliana.

Phenotypic plasticity is a heritable trait that provides sessile organisms a strategy to rapidly mitigate negative effects of environmental change. Yet, we have little understanding of the mode of inheritance and genetic architecture of plasticity in different focal traits relevant to agricultural applications. This study builds on our recent discovery of genes controlling temperature-mediated flower size plasticity in Arabidopsis thaliana and focuses on dissecting the mode of inheritance and combining ability of plasticity in the context of plant breeding. We created a full diallel cross using 12 A. thaliana accessions displaying different temperature-mediated flower size plasticities, scored as the fold change between two temperatures. Griffing's analysis of variance in flower size plasticity indicated that non-additive genetic action shapes this trait and pointed at challenges and opportunities when breeding for reduced plasticity. Our findings provide an outlook of flower size plasticity that is important for developing resilient crops for future climates.

Genomic technologies to improve variation identification in undiagnosed diseases.

Human genome variation has increasingly posed challenges and opportunities for patients, medical providers, and an increasing group of stakeholders including advocacy groups, disadvantaged communities, public health experts, and scientists. Here, advances in genomic sequencing and mapping technologies are discussed with particular attention to the increasing ability to detect personal and population genome variation and the potential for accurate integration of variation into health and disease-related care. Genome mapping, one technique used to create genome map scaffolds, has now been combined with long read sequencing. New technologies have led to improved variation detection, including cryptic structural variation and diverse variants with different degrees of disease association. Combined with advances in automated and medical interpretations, variation detection is increasingly being applied in healthcare. These advances promise to make disease diagnostics more rapid, and potentially more accessible, to those with medical needs. Consequentially, the need for medical genetics and genomics experts is increasing. Here, the opportunities and potential challenges for application of genome-scale variation detection in disease are examined. (<300 words).

Cronología de la erupción dentaria en adolescentes de 13 años del municipio Sancti Spíritus

Introducción: La erupción dentaria es un proceso fisiológico que puede ser alterado por múltiples causas congénitas o ambientales. Objetivo: Determinar la cronología de la erupción dentaria permanente y su relación con factores influyentes en adolescentes de 13 años del municipio Sancti Spíritus. Métodos: Se realizó un estudio descriptivo, transversal en el municipio Sancti Spíritus entre septiembre 2017 y junio de 2019. La población estuvo constituida por 1 355 adolescentes de 13 años pertenecientes a todas las escuelas secundarias básicas urbanas de este municipio y por muestreo estratificado en dos etapas se seleccionó una muestra de 406 adolescentes. Se utilizaron métodos del nivel teórico, empírico y estadístico-matemático. Resultados: Se constató que el 22,9 % de los adolescentes presentaron la cronología de la erupción dentaria atrasada respecto a las medidas de Mayoral con predominio del sexo masculino (57 %) y el grupo étnico europoide (83,9 %). Los factores que más influyeron fueron la retención de dientes temporales con 72 %, el sexo con 57 % y los antecedentes hereditarios con 49,5 %, los tres con gran significación estadística. Conclusiones: Casi la cuarta parte de los adolescentes de 13 años estudiados del municipio Sancti Spíritus presentan atraso en la cronología de la erupción dentaria permanente respecto a los valores de Mayoral. Los del sexo masculino presentaron el doble de riesgo para una cronología atrasada y no existieron diferencias en cuanto al grupo étnico. Los factores que más influyeron fueron la herencia, el sexo y la retención de dientes temporales.

Introduction: Tooth eruption is a physiological process that can be altered by multiple congenital or environmental causes. Objective: To determine the chronology of permanent dental eruption and its relationship with influencing factors in 13-year-old adolescents from the Sancti Spíritus municipality. Methods: A cross-sectional descriptive study was carried out in the Sancti Spíritus municipality from September 2017 to June 2019. The population consisted of 1 355 13-year-old adolescents belonging to all the urban basic secondary schools of this municipality and by stratified sampling in two stages. A sample of 406 adolescents was selected. Theoretical, empirical and statistical-mathematical level methods were used. Results: It was found that 22.9% of the adolescents presented delayed dental eruption chronology with respect to the Mayoral measures, with a predominance of males (57%) and the Europoid ethnic group (83.9%). The factors that most influenced were the retention of temporary teeth with 72%, sex with 57% and hereditary history with 49.5%, the three variables with great statistical significance. Conclusions: Almost a quarter of the 13-year-old adolescents studied in the municipality of Sancti Spíritus presents a delay in the chronology of permanent dental eruption with respect to the Mayoral values. Those of the masculine sex presented double the risk for a delayed chronology and there were no differences regarding the ethnic group. The factors that most influenced were heredity, sex and retention of temporary teeth.

Investigation of ALPL variant states and clinical outcomes: An analysis of adults and adolescents with hypophosphatasia treated with asfotase alfa.

BACKGROUND: Hypophosphatasia (HPP), a rare metabolic disease, can be inherited in an autosomal recessive (biallelic) or an autosomal dominant (monoallelic) manner. Most of the severe, early-onset, frequently lethal HPP in infants is acquired through recessive inheritance; less severe, later-onset, typically nonlethal HPP phenotypes are acquired through either dominant or recessive inheritance. HPP's variable clinical presentation arises from >400 identified ALPL pathogenic variants with likely variable penetrance, especially with autosomal dominant inheritance. This post hoc analysis investigated the relationship between ALPL variant state (biallelic and monoallelic) and clinical outcomes with asfotase alfa in HPP. METHODS: Data were pooled from two phase 2, randomized, open-label studies in adolescents and adults with HPP; one study evaluated the efficacy and safety of different doses of asfotase alfa (n = 25), and the other assessed the pharmacodynamics and safety of asfotase alfa (n = 19). Patients were grouped by ALPL variant state (biallelic or monoallelic). Available data from both studies included ALPL pathogenic variant state, Baseline characteristics, HPP-specific medical history, and Baseline TNSALP substrate levels (inorganic pyrophosphate [PPi] and pyridoxal 5'-phosphate [PLP]) concentrations). Clinical outcomes over 5 years of treatment were available from only the efficacy and safety study. RESULTS: In total, 44 patients with known variant status were included in the pooled analysis (biallelic, n = 30; monoallelic, n = 14). The most common pathogenic variant was c.571G > A (p.Glu191Lys) in biallelic patients (allele frequency: 19/60) and c.1133A > T (p.Asp378Val) in monoallelic patients (allele frequency: 7/28). Median (min, max) Baseline PPi concentrations were significantly higher in patients with a biallelic vs monoallelic variant state (5.3 [2.2, 12.1] vs 4.3 [3.5, 7.4] µM; P = 0.0113), as were Baseline PLP concentrations (221.4 [62.4, 1590.0] vs 75.1 [28.8, 577.0] ng/mL; P= 0.0022). HPP-specific medical history was generally similar between biallelic and monoallelic patients in terms of incidence and type of manifestations; notable exceptions included fractures, which were more common among monoallelic patients, and delayed walking and bone deformities such as abnormally shaped chest and head and bowing of arms or legs, which were more common among biallelic patients. Data from the efficacy and safety study (n = 19) showed that median PPi and PLP concentrations were normalized over 5 years of treatment in patients with both variant states. Median % predicted distance walked on the 6-Minute Walk Test remained within the normal range for monoallelic patients over 4 years of treatment, and improved from below normal (<84%) to normal in biallelic patients. CONCLUSIONS: Although patients with biallelic variants had significantly higher Baseline PPi and PLP levels than monoallelic variants, both groups generally showed similar pretreatment Baseline clinical characteristics. Treatment with asfotase alfa for up to 5 years normalized TNSALP substrate concentrations and improved functional outcomes, with no clear differences between biallelic and monoallelic variant states. This study suggests that patients with HPP have significant disease burden, regardless of ALPL variant state.

Heritability of sleep duration and quality: A systematic review and meta-analysis.

Epidemiological and interventional research has highlighted sleep as a potentially modifiable risk factor associated with poor physical and mental health. Emerging evidence from (behavioral) genetic research also shows that sleep characteristics are under strong genetic control. With this study we aimed to meta-analyze the literature in this area to quantify the heritability of sleep duration and sleep quality in the general population. We conducted a systematic literature search in five online databases on January 24th 2020. Two authors independently screened 5644 abstracts, and 160 complete articles for the inclusion criteria of twin studies from the general population reporting heritability statistics on sleep duration and/or quality, and written in English. We ultimately included 23 papers (19 independent samples: 45,328 twins between 6 mo and 88 y) for sleep duration, and 13 papers (10 independent samples: 39,020 twins between 16 and 95 y) for sleep quality. Collectively, we showed that 46% of the variability in sleep duration and 44% of the variability in sleep quality is genetically determined. The remaining variation in the sleep characteristics can mostly be attributed to the unique environment the twins experience, although the shared environment seemed to play a role for the variability of childhood sleep duration. Meta-analyzed heritability estimates for sleep duration, however, varied substantially with age (17% infancy, 20-52% childhood, 69% adolescence and 42-45% adulthood) and reporter (8% parent-report, 38-52% self-report). Heritability estimates for actigraphic and Polysomnography (PSG)-estimated sleep were based on few small samples, warranting more research. Our findings highlight the importance of considering genetic influences when aiming to understand the underlying mechanisms contributing to the trajectories of sleep patterns across the lifespan.

The heritability of insomnia: A meta-analysis of twin studies.

Twin studies of insomnia exhibit heterogeneity in estimates of heritability. This heterogeneity is likely because of sex differences, age of the sample, the reporter and the definition of insomnia. The aim of the present study was to systematically search the literature for twin studies investigating insomnia disorder and insomnia symptoms and to meta-analyse the estimates of heritability derived from these studies to generate an overall estimate of heritability. We further examined whether heritability was moderated by sex, age, reporter and insomnia symptom. A systematic literature search of five online databases was completed on 24 January 2020. Two authors independently screened 5644 abstracts, and 160 complete papers for the inclusion criteria of twin studies from the general population reporting heritability statistics on insomnia or insomnia symptoms, written in English, reporting data from independent studies. We ultimately included 12 papers in the meta-analysis. The meta-analysis focussed on twin intra-class correlations for monozygotic and dizygotic twins. Based on these intra-class correlations, the meta-analytic estimate of heritability was estimated at 40%. Moderator analyses showed stronger heritability in females than males; and for parent-reported insomnia symptoms compared with self-reported insomnia symptoms. There were no other significant moderator effects, although this is likely because of the small number of studies that were comparable across levels of the moderators. Our meta-analysis provides a robust estimate of the heritability of insomnia, which can inform future research aiming to uncover molecular genetic factors involved in insomnia vulnerability.

Inheritance pattern of molar-incisor hypomineralization

Abstract The aim of this study was to investigate the segregation patterns of molar incisor hypomineralization (MIH) in families, given the evidence that its etiology is influenced by genetics. Clinically, MIH may be detected in parents and/or siblings of MIH-affected children. Our study included children with at least one first permanent molar affected by MIH (proband) and their first-degree relatives (parents and siblings). The participants were examined clinically to detect MIH, according to the European Academy of Paediatric Dentistry criteria (2003). A total of 101 nuclear families (391 individuals) were studied. Proband diagnosis was followed by MIH classification of the subject, his parents and siblings, as affected, unaffected, or unknown. Segregation analysis was performed using the multivariate logistic regression model of the Statistical Analysis for Genetic Epidemiology package, and segregation models (general transmission, environmental, major gene, dominant, codominant and recessive models). The Akaike information criterion (AIC) was used to evaluate the most parsimonious model. In all, 130 affected individuals, 165 unaffected individuals, and 96 unknown individuals were studied. Severe MIH was found in 50.7% of the cases. A segregation analysis performed for MIH revealed the following different models: environmental and dominance (p = 0.05), major gene (p = 0.04), codominant (p = 0.15) and recessive models (p = 0.03). According to the AIC values, the codominant model was the most parsimonious (AIC = 308.36). Our results suggest that the codominant model could be the most likely for inheriting MIH. This result strengthens the evidence that genetic factors, such as multifactorial complex defect, influence MIH.

Inherited epidermolysis bullosa: update on the clinical and genetic aspects

Abstract Inherited epidermolysis bullosa is a group of genetic diseases characterized by skin fragility and blistering on the skin and mucous membranes in response to minimal trauma. Epidermolysis bullosa is clinically and genetically very heterogeneous, being classified into four main types according to the layer of skin in which blistering occurs: epidermolysis bullosa simplex (intraepidermal), junctional epidermolysis bullosa (within the lamina lucida of the basement membrane), dystrophic epidermolysis bullosa (below the basement membrane), and Kindler epidermolysis bullosa (mixed skin cleavage pattern). Furthermore, epidermolysis bullosa is stratified into several subtypes, which consider the clinical characteristics, the distribution of the blisters, and the severity of cutaneous and extracutaneous signs. Pathogenic variants in at least 16 genes that encode proteins essential for the integrity and adhesion of skin layers have already been associated with different subtypes of epidermolysis bullosa. The marked heterogeneity of the disease, which includes phenotypes with a broad spectrum of severity and many causal genes, hinders its classification and diagnosis. For this reason, dermatologists and geneticists regularly review and update the classification criteria. This review aimed to update the state of the art on inherited epidermolysis bullosa, with a special focus on the associated clinical and genetic aspects, presenting data from the most recent reclassification consensus, published in 2020.

Educational Case: Autosomal Dominant Polycystic Kidney Disease.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.1.

Inherited epidermolysis bullosa: update on the clinical and genetic aspects.

Inherited epidermolysis bullosa is a group of genetic diseases characterized by skin fragility and blistering on the skin and mucous membranes in response to minimal trauma. Epidermolysis bullosa is clinically and genetically very heterogeneous, being classified into four main types according to the layer of skin in which blistering occurs: epidermolysis bullosa simplex (intraepidermal), junctional epidermolysis bullosa (within the lamina lucida of the basement membrane), dystrophic epidermolysis bullosa (below the basement membrane), and Kindler epidermolysis bullosa (mixed skin cleavage pattern). Furthermore, epidermolysis bullosa is stratified into several subtypes, which consider the clinical characteristics, the distribution of the blisters, and the severity of cutaneous and extracutaneous signs. Pathogenic variants in at least 16 genes that encode proteins essential for the integrity and adhesion of skin layers have already been associated with different subtypes of epidermolysis bullosa. The marked heterogeneity of the disease, which includes phenotypes with a broad spectrum of severity and many causal genes, hinders its classification and diagnosis. For this reason, dermatologists and geneticists regularly review and update the classification criteria. This review aimed to update the state of the art on inherited epidermolysis bullosa, with a special focus on the associated clinical and genetic aspects, presenting data from the most recent reclassification consensus, published in 2020.

Caracterización clínico-epidemiológica en pacientes discapacitados visuales por retinosis pigmentaria. Sancti Spíritus. 2009-2019 / Clinical and epidemiological characterization in visual impaired patients due to retinitis pigmentosa. Sancti Spíritus. 2009-2019

RESUMEN Fundamento: La retinosis pigmentaria constituye una causa de discapacidad visual que provoca alteraciones psicológicas y sociales al paciente. Objetivo: Describir las características clínicas y epidemiológicas en pacientes discapacitados visuales por retinosis pigmentaria de la provincia Sancti Spíritus. Metodología: Se realizó un estudio descriptivo, que incluyó 140 pacientes discapacitados visuales afectados por retinosis pigmentaria. Resultados: El grupo etario entre los 29 y 56 años fue el más afectado (78.1 %), el 65 % era del sexo masculino, predominó el color blanco de la piel (87.1 %), sobresalió la catarata como la afección ocular (13.6 %), el 16.4 % presentó hipertensión arterial; la mayoría de los discapacitados no presentó hábitos tóxicos (55 %), prevaleció el debut precoz en el 70 % de los casos. La forma típica de la enfermedad se observó en el 98.5 % de los enfermos, el 67 % manifestó un estadio clínico de la enfermedad grado IV, así como la herencia autosómica recesiva en el 36.4 %. Conclusiones: Predominio de los enfermos en los grupos etario entre 29 y 56 años, masculino, color blanco de la piel; la catarata como patología ocular más frecuente junto a la hipertensión arterial dentro las enfermedades sistémicas; la mayoría de los discapacitados no presentó hábitos tóxicos. El debut precoz, la forma típica, el estadio IV de la enfermedad, así como la herencia autosómica dominante prevalecieron en el estudio.

ABSTRACT Background: Retinitis pigmentosa is a cause of visual impairment that causes psychological and social alterations to the patient. Objective: To describe the clinical and epidemiological characteristics in visual impaired patients due to retinitis pigmentosa in Sancti Spíritus province. Methodology: A descriptive study was carried out, which included 140 visual impaired patients affected by retinitis pigmentosa. Results: The age group between 29 and 56 years old was the most affected (78.1 %), 65 % were male, white skin predominated (87.1 %), cataract stood out as an eye condition (13.6 %), 16.4 % presented arterial hypertension; most of the disabled did not present toxic habits (55 %), early debut prevailed in 70 % of cases. The typical form of the disease was observed in 98.5 % of patients, 67 % showed a clinical stage of grade IV disease, as well as autosomal recessive inheritance in 36.4 %. Conclusions: Prevalence of patients in the age groups between 29 and 56 years, male, white skin color; cataract as the most frequent ocular pathology together with arterial hypertension within systemic diseases; the majority of the disabled patients did not show toxic habits. Early debut, typical form, stage IV disease, and autosomal dominant inheritance prevailed in the study.

Caracterización clínico-epidemiológica en pacientes discapacitados visuales por retinosis pigmentaria. Sancti Spíritus. 2009-2019 / Clinical and epidemiological characterization in visual impaired patients due to retinitis pigmentosa. Sancti Spíritus. 2009-2019

RESUMEN Fundamento: La retinosis pigmentaria constituye una causa de discapacidad visual que provoca alteraciones psicológicas y sociales al paciente. Objetivo: Describir las características clínicas y epidemiológicas en pacientes discapacitados visuales por retinosis pigmentaria de la provincia Sancti Spíritus. Metodología: Se realizó un estudio descriptivo, que incluyó 140 pacientes discapacitados visuales afectados por retinosis pigmentaria. Resultados: El grupo etario entre los 29 y 56 años fue el más afectado (78.1 %), el 65 % era del sexo masculino, predominó el color blanco de la piel (87.1 %), sobresalió la catarata como la afección ocular (13.6 %), el 16.4 % presentó hipertensión arterial; la mayoría de los discapacitados no presentó hábitos tóxicos (55 %), prevaleció el debut precoz en el 70 % de los casos. La forma típica de la enfermedad se observó en el 98.5 % de los enfermos, el 67 % manifestó un estadio clínico de la enfermedad grado IV, así como la herencia autosómica recesiva en el 36.4 %. Conclusiones: Predominio de los enfermos en los grupos etario entre 29 y 56 años, masculino, color blanco de la piel; la catarata como patología ocular más frecuente junto a la hipertensión arterial dentro las enfermedades sistémicas; la mayoría de los discapacitados no presentó hábitos tóxicos. El debut precoz, la forma típica, el estadio IV de la enfermedad, así como la herencia autosómica dominante prevalecieron en el estudio.

ABSTRACT Background: Retinitis pigmentosa is a cause of visual impairment that causes psychological and social alterations to the patient. Objective: To describe the clinical and epidemiological characteristics in visual impaired patients due to retinitis pigmentosa in Sancti Spíritus province. Methodology: A descriptive study was carried out, which included 140 visual impaired patients affected by retinitis pigmentosa. Results: The age group between 29 and 56 years old was the most affected (78.1 %), 65 % were male, white skin predominated (87.1 %), cataract stood out as an eye condition (13.6 %), 16.4 % presented arterial hypertension; most of the disabled did not present toxic habits (55 %), early debut prevailed in 70 % of cases. The typical form of the disease was observed in 98.5 % of patients, 67 % showed a clinical stage of grade IV disease, as well as autosomal recessive inheritance in 36.4 %. Conclusions: Prevalence of patients in the age groups between 29 and 56 years, male, white skin color; cataract as the most frequent ocular pathology together with arterial hypertension within systemic diseases; the majority of the disabled patients did not show toxic habits. Early debut, typical form, stage IV disease, and autosomal dominant inheritance prevailed in the study.

Transethnic Genome-Wide Association Study Provides Insights in the Genetic Architecture and Heritability of Long QT Syndrome.

BACKGROUND: Long QT syndrome (LQTS) is a rare genetic disorder and a major preventable cause of sudden cardiac death in the young. A causal rare genetic variant with large effect size is identified in up to 80% of probands (genotype positive) and cascade family screening shows incomplete penetrance of genetic variants. Furthermore, a proportion of cases meeting diagnostic criteria for LQTS remain genetically elusive despite genetic testing of established genes (genotype negative). These observations raise the possibility that common genetic variants with small effect size contribute to the clinical picture of LQTS. This study aimed to characterize and quantify the contribution of common genetic variation to LQTS disease susceptibility. METHODS: We conducted genome-wide association studies followed by transethnic meta-analysis in 1656 unrelated patients with LQTS of European or Japanese ancestry and 9890 controls to identify susceptibility single nucleotide polymorphisms. We estimated the common variant heritability of LQTS and tested the genetic correlation between LQTS susceptibility and other cardiac traits. Furthermore, we tested the aggregate effect of the 68 single nucleotide polymorphisms previously associated with the QT-interval in the general population using a polygenic risk score. RESULTS: Genome-wide association analysis identified 3 loci associated with LQTS at genome-wide statistical significance (P<5×10-8) near NOS1AP, KCNQ1, and KLF12, and 1 missense variant in KCNE1(p.Asp85Asn) at the suggestive threshold (P<10-6). Heritability analyses showed that ≈15% of variance in overall LQTS susceptibility was attributable to common genetic variation (h2SNP 0.148; standard error 0.019). LQTS susceptibility showed a strong genome-wide genetic correlation with the QT-interval in the general population (rg=0.40; P=3.2×10-3). The polygenic risk score comprising common variants previously associated with the QT-interval in the general population was greater in LQTS cases compared with controls (P<10-13), and it is notable that, among patients with LQTS, this polygenic risk score was greater in patients who were genotype negative compared with those who were genotype positive (P<0.005). CONCLUSIONS: This work establishes an important role for common genetic variation in susceptibility to LQTS. We demonstrate overlap between genetic control of the QT-interval in the general population and genetic factors contributing to LQTS susceptibility. Using polygenic risk score analyses aggregating common genetic variants that modulate the QT-interval in the general population, we provide evidence for a polygenic architecture in genotype negative LQTS.