Novel MYT1 variants expose the complexity of oculo-auriculo-vertebral spectrum genetic mechanisms.

Oculo-auriculo-vertebral spectrum (OAVS) is a developmental disorder characterized by anomalies mainly involving the structures derived from the first and second pharyngeal arches. The spectrum presents with heterogeneous clinical features and complex etiology with genetic factors not yet completely understood. To date, MYT1 is the most important gene unambiguously associated with the spectrum and with functional data confirmation. In this work, we aimed to identify new single nucleotide variants (SNVs) affecting MYT1 in a cohort of 73 Brazilian patients diagnosed with OAVS. In addition, we investigated copy number variations (CNVs) encompassing this gene or its cis-regulatory elements and compared the frequency of these events in patients versus a cohort of 455 Brazilian control individuals. A new SNV, predicted as likely deleterious, was identified in five unrelated patients with OAVS. All five patients presented hearing impairment and orbital asymmetry suggesting an association with the variant. CNVs near MYT1, located in its neighboring topologically associating domain (TAD), were found to be enriched in patients when compared to controls, indicating a possible involvement of this region with OAVS pathogenicity. Our findings highlight the genetic complexity of the spectrum that seems to involve more than one variant type and inheritance patterns.

Copy number variation (CNV) identification, interpretation, and database from Brazilian patients.

Copy number variations (CNVs) constitute an important class of variation in the human genome and the interpretation of their pathogenicity considering different frequencies across populations is still a challenge for geneticists. Since the CNV databases are predominantly composed of European and non-admixed individuals, and Brazilian genetic constitution is admixed and ethnically diverse, diagnostic screenings on Brazilian variants are greatly difficulted by the lack of populational references. We analyzed a clinical sample of 268 Brazilian individuals, including patients with neurodevelopment disorders and/or congenital malformations. The pathogenicity of CNVs was classified according to their gene content and overlap with known benign and pathogenic variants. A total of 1,504 autosomal CNVs (1,207 gains and 297 losses) were classified as benign (92.9%), likely benign (1.6%), VUS (2.6%), likely pathogenic (0.2%) and pathogenic (2.7%). Some of the CNVs were recurrent and with frequency increased in our sample, when compared to populational open resources of structural variants: 14q32.33, 22q11.22, 1q21.1, and 1p36.32 gains. Thus, these highly recurrent CNVs classified as likely benign or VUS were considered non-pathogenic in our Brazilian sample. This study shows the relevance of introducing CNV data from diverse cohorts to improve on the interpretation of clinical impact of genomic variations.

Atypical Prader-Willi and 15q13.3 Microdeletion Syndromes in a Patient with an Unbalanced Translocation.

Prader-Willi syndrome (PWS) and recurrent 15q13.3 microdeletion syndrome can be caused by genomic rearrangements in the complex 15q11q13 chromosomal region. Here, we describe the first female child with PWS and 15q13.3 microdeletion syndrome resulting from an unusual 10.7-Mb deletion from 15pter to 15q13.3 due to an unbalanced de novo 15;19 translocation. The patient presents with hypotonia, microcephaly, developmental delay with lack of speech, intellectual disability, happy demeanor, clinodactyly of the 4th and 5th fingers, and dysmorphic facial features discordant for PWS and consistent with an atypical phenotype.

Clinical and cytogenomic findings in OAV spectrum.

The oculoauriculovertebral spectrum (OAVS) is characterized by anomalies involving the development of the first and second pharyngeal arches during the embryonic period. The phenotype is highly heterogeneous, involving ears, eyes, face, neck, and other systems and organs. There is no agreement in the literature for the minimum phenotypic inclusion criteria, but the primary phenotype involves hemifacial microsomia with facial asymmetry and microtia. Most cases are sporadic and the etiology of this syndrome is not well known. Environmental factors, family cases that demonstrate Mendelian inheritance, such as preauricular appendages, microtia, mandibular hypoplasia, and facial asymmetry; chromosomal abnormalities and some candidate genes suggest a multifactorial inheritance model. We evaluated clinical, cytogenomic and molecularly 72 patients with OAVS, and compared our findings with patients from the literature. We found 15 CNVs (copy number variations) considered pathogenic or possibly pathogenic in 13 out of 72 patients. Our results did not indicated a single candidate genomic region, but recurrent chromosomal imbalances were observed in chromosome 4 and 22, in regions containing genes relevant to the OAVS phenotype or related to known OMIM diseases suggesting different pathogenic mechanisms involved in this genetically and phenotypic heterogeneous spectrum.

Miller-Dieker Syndrome due to a 5.5-Mb 17p Deletion in a 17;Y Pseudodicentric Chromosome.

Miller-Dieker syndrome (MDS) is a contiguous gene deletion syndrome in which almost all patients present de novo 17p13.3 deletions. We report on a male infant with MDS and an unusual unbalanced translocation involving chromosomes Y and 17 that resulted in a large 5.5-Mb 17pterp13.2 deletion and a karyotype with 45 chromosomes. Apart from the deletion of the MDS critical region, the deletion of additional distal genes seemed to have no major influence on the patient's phenotype, since he did not show any unusual clinical findings that are not commonly described in MDS patients.

Deletion 21pterq22.11: Report of a Patient with Dysmorphic Features, Hypertonia, and Café-au-Lait Macules and Review of the Literature.

Partial monosomy 21 results in a great variability of clinical features that may be associated with the size and location of the deletion. In this study, we report a 22-month-old girl who showed a 45,XX,add(12)(p13)dn,-21 karyotype. The final cytogenomic result was 45,XX,der(12)t(12;21)(p13;q22.11) dn,-21.arr[hg19] 21q11.2q22.11(14824453_33868129)×1 revealing a deletion from 21pter to 21q22.11. Clinical manifestation of the patient included hypertonia, a long philtrum, epicanthic folds, low-set ears, and café-au-lait macules - a phenotype considered as mild despite the relatively large size of the deletion compared to patients from the literature.

Wolf-Hirschhorn Syndrome with Epibulbar Dermoid: An Unusual Association in a Patient with 4p Deletion and Functional Xp Disomy.

Wolf-Hirschhorn syndrome (WHS) is a contiguous gene and multiple malformation syndrome that results from a deletion in the 4p16.3 region. We describe here a 6-month-old girl that presented with WHS features but also displayed unusual findings, such as epibulbar dermoid in the left eye, ear tags, and left microtia. Although on G-banding her karyotype appeared to be normal, chromosomal microarray analysis revealed an ∼13-Mb 4p16.3p15.33 deletion and an ∼9-Mb Xp22.33p22.31 duplication, resulting from a balanced maternal t(X;4)(p22.31;p15.33) translocation. The patient presented with functional Xp disomy due to an unbalanced X-autosome translocation, a rare cytogenetic finding in females with unbalanced rearrangements. Sequencing of both chromosome breakpoints detected no gene disruption. To the best of our knowledge, this is the first patient described in the literature with WHS and epibulbar dermoid, a typical characteristic of the oculoauriculovertebral spectrum (OAVS). Our data suggest that possible candidate genes for OAVS may have been deleted along with the WHS critical region.

Unusual Duplication in the Pericentromeric Region of Chromosome 9 in a Patient with Phenotypic Alterations.

Several alterations involving the pericentromeric region of chromosome 9 are considered as normal population variants. These heterochromatic variants or heteromorphisms can include 9qh+, 9cen+, 9ph+, 9ph-, inv(9)(p11q13), and other patterns which can only be defined by FISH studies. However, some heteromorphisms have been found more frequently in patients with several clinical disorders. Here, we report on a patient with intellectual disability, language and neurodevelopmental delay, as well as facial dysmorphism and an unusual chromosome 9. While the banding karyotype was indicative of a simple pericentric inversion of one chromosome 9 [46,XX,inv(9)(p12q13)], array comparative genomic hybridization showed a 6-Mb duplication, including 22 genes: arr[hg19] 9p13.1p11.2(38,869,901- 44,870,714)×3 dn. Molecular cytogenetics using a panel of probes specific for the pericentromeric region of chromosome 9 showed an unusual, rearranged chromosome 9, der(9)(pter→p11.2::q21.11→q12::p11.2→p13.2::q12→p11.2::q21.11→qter), that has not been described before. The patient's phenotypic alterations are probably due to the de novo 6-Mb 9p duplication, although a review of similar cases showed some reports considering this duplication in the euchromatic region as a benign variant. Interestingly, this is the first report of a possible adverse inversion loop formation due to a known heteromorphic pericentric inversion present in the phenotypically normal father of the patient.

Atypical 581-kb 22q11.21 Deletion in a Patient with Oculo-Auriculo-Vertebral Spectrum Phenotype.

The oculo-auriculo-vertebral spectrum (OAVS) is defined as a group of malformations involving the ears, mouth, mandible, eyes, and cervical spine. Establishing an accurate clinical diagnosis of OAVS is a challenge for clinical geneticists, not only because these patients display heterogeneous phenotypes, but also because its etiology encompasses environmental factors, unknown genetic factors and different chromosome aberrations. To date, several chromosomal abnormalities have been associated with the syndrome, most frequently involving chromosome 22. In the literature, six 22q11.2 microdeletions have been described within the same region, suggesting possible OAVS candidate genes in this segment. Here, we report on a patient with an ∼581-kb 22q11.21 deletion, detected by genomic array and MLPA. This is the 7th case described with OAVS and 22q deletion, suggesting that the 22q11.2 region may be related to the regulation of body symmetry and facial development.

Quality of systematic reviews on the treatment of vesiculobullous skin diseases. A meta-epidemiological study.

BACKGROUND: Systematic reviews of Randomized Controlled Trials (RCTs) are considered high-level evidence to support a decision on therapeutic interventions, and their methodological quality is essential to provide reliable and applicable results. OBJECTIVE: This meta-epidemiological study aimed to map and critically appraise systematic reviews assessing treatments for vesiculobullous skin diseases. METHODS: We conducted a comprehensive search strategy on MEDLINE (via Pubmed) in December 2022 without restrictions to find systematic reviews evaluating pharmacological interventions for vesiculobullous skin diseases. The methodological quality was assessed using the AMSTAR-2 tool, and additional information was extracted. We identified nine systematic reviews published between 2002 and 2021, seven assessing pemphigus. RESULTS: According to the AMSTAR-2 tool, 55.6% were classified as critically low quality, 22.2% as moderate quality, 11.1% as low and 11.1% as high quality. No review assessed the certainty of the evidence (GRADE); 86% of pemphigus reviews had at least two overlapping RCTs. There were some limitations regarding methodological flaws and the AMSTAR-2 tool use CONCLUSIONS: These findings reveal a frail methodological quality of systematic reviews about vesiculobullous diseases treatment that may impact the results. Therefore, methodological rigor is mandatory for future systematic reviews to avoid duplication of effort and increase the certainty of the evidence supporting decision-making.

Resistance training for postmenopausal women: systematic review and meta-analysis.

IMPORTANCE: Numerous studies have been published assessing the effects of resistance muscle training to mitigate menopausal symptoms, given the endocrine muscle function and its metabolic regulation. Therefore, mapping and synthesizing high-quality studies are necessary to help clinical decisions. OBJECTIVE: The aim of this study was to assess the effects (benefits and harms) of resistance muscle training for postmenopausal women. EVIDENCE REVIEW: Electronic searches were conducted in MEDLINE (via PubMed), EMBASE, CENTRAL, PEDro, LILACS, and SPORTDiscus up to December 2021. Two independent reviewers selected the retrieved references and extracted relevant data from included studies. The methodological quality (risk of bias) using the Cochrane Risk of Bias table and the certainty of the evidence (GRADE approach) were assessed. FINDINGS: Twelve randomized clinical trials (n = 452) with unclear to high risk of bias were identified. Compared with no exercise, resistance training (up to 16 weeks) seems to promote an improvement in functional capacity (mean difference [MD], 2.90 points; 95% CI, 0.60-5.20) and bone mineral density (MD, 0.10; 95% CI, 0.10-0.10) and a reduction in the hot flash frequency (13/29 vs 1/29; risk ratio, 13.0; 95% CI, 1.82-93.01) and fat mass (MD, -3.15; 95% CI, -6.68 to 0.38), and no differences were observed between groups regarding abdominal circumference and body mass index. When compared with aerobic exercises, resistance training may result in a reduction of hot flash frequency (7/18 vs 14/18; risk ratio, 0.50; 95% CI, 0.27-0.94) and fat mass (MD, -7.80; 95% CI, -14.02 to -1.58) and no difference in the quality of life and body mass index. Regarding safety, no serious adverse events were reported. Based on the GRADE approach, the certainty of this evidence was graded as very low to low, leading to imprecisely estimated effects. CONCLUSIONS AND RELEVANCE: Resistance muscle training seems to improve postmenopausal symptoms and functional capacity. Given the low to very low certainty of the evidence, further randomized clinical trials with higher methodological quality and better reports are still needed. As an implication for clinical practice, health professionals should consider individualized aspects such as the previous history of exercise practice, physical capacity, and adaptation period.

The Differential Effect of Schooling and Physical Activity on Dementia in Older Women and Men from Brazil: Implications for Policymaking.

BACKGROUND: Modifiable risk factors exert crucial impact on dementia. OBJECTIVE: We sought to answer the question: do two modifiable risk factors, schooling level and physical activity (PA), affect cognitive function similarly in each sex? METHODS: This cross-sectional study was conducted in 2019 and 2021, and the survey was applied to the residents of the metropolitan area of Santos, a seashore of Sao Paulo State. Four hundred and twenty-two participants (women = 254 and men = 168) were eligible. Baecke questionnaire for the elderly was applied for the classification as physically inactive (PI) or active (PA). Cognitive function was assessed by the Mini-Mental State Examination (MMSE) and the Clinical Dementia Rating (CDR). Participants were also stratified by schooling status for both sexes. RESULTS: Higher education had a sex-independent positive influence on MMSE and CDR (p < 0.001). PA influences positively MMSE in older women (PI: 25±5 and PA: 27±3, p < 0.03), but has no effect in older men (26±5 and 25±5, p > 0.05). Concordantly, older women who were PA (1.7 and 0 %) showed a lower prevalence of dementia compared with PI (6.2 and 2.1%), for mild and moderate respectively. Active older women had higher odds of improving the MMSE score (OR: 1.093; 95% CI: 1.008-1.186) than men (OR: 0.97 (95% CI: 0.896-1.051). CONCLUSION: Education affects cognitive function equally in Brazilian elderly whereas older women are more responsive to the beneficial effects of PA for dementia than men.

Association between genetic polymorphisms and osteoarthritis development. Overview of systematic reviews.

OBJECTIVE: To identify, critically evaluate and synthesize the evidence obtained from systematic reviews on the association between genetic polymorphisms and osteoarthritis (OA) development. METHODS: Considering gene polymorphisms associated with OA susceptibility (risk or protection), a comprehensive search was conducted in the following databases, without date or language restrictions: MEDLINE, via Pubmed; Embase, via Elsevier; Cochrane Database of Systematic Reviews, via Wiley; Biblioteca Virtual em Saúde. Gray literature was also searched through the OpenGrey database. The AMSTAR-2 (Assessing the Methodological Quality of Systematic Reviews) was used to assess the methodological quality of the included systematic reviews. RESULTS: We included 14 systematic reviews of case-control studies comparing individuals with a radiographic diagnosis of all OA types and healthy controls, all submitted to the genetic examination of different polymorphisms in candidate genes. Meta-analyses showed a protective effect against knee and hand OA associated with GDF-5 gene (odds ratio [OR] 0.90, 95% confidence interval (CI) 0.85-0.95), and knee OA with ESRα gene (OR 0.63, 95% CI 1.26-1.97). SMAD3 gene was associated with knee and hip OA risk (OR 1.21. 95% CI 1.07-1.38) and MMP-1 gene was associated with temporomandibular OA (OR 1.58. 95% CI 1.26-1.97). CONCLUSION: Based on low-quality to critically-low-quality systematic reviews, some gene polymorphisms seem to be associated with risk or protection for OA. Further high-quality studies are needed to validate these hypotheses, contribute to disease understanding, and possibly help the decision-making related to early diagnosis and treatment options for OA. PROSPERO register CRD42021234231.

INTERVENTIONS FOR THE TREATMENT OF IRRITABLE BOWEL SYNDROME: A REVIEW OF COCHRANE SYSTEMATIC REVIEWS.

BACKGROUND: Irritable bowel syndrome (IBS) is a complex gastrointestinal disorder, whose understanding is relatively uncertain, and the treatment guidance decision still represents a challenge. OBJECTIVE: To identify and critically appraise systematic reviews (SRs) published in the Cochrane Database of SRs (CDSR) on the effects of interventions (pharmacological and non-pharmacological) for the treatment of IBS. METHODS: The search was conducted at the Cochrane Library in May 2020. The methodological quality of the SRs was evaluated by the AMSTAR-2 tool. RESULTS: Eight SRs with moderate to high quality were included, which addressed the treatments: (a) pharmacological: volume agents, antispasmodics, antidepressants and tegaserod; and (b) non-pharmacological: homeopathy, acupuncture, phytotherapy, biofeedback, psychological interventions and hypnotherapy. The results were favorable to antispasmodic drugs and antidepressants regarding the improvement of clinical symptoms. There was no difference between volume agents or tegaserod when compared to placebo. Acupuncture and homeopathy showed a little improvement in symptoms compared to placebo, but the certainty of this evidence was considered low to very low. Psychological interventions seem to improve the overall assessment of the patient and relief symptoms such as abdominal pain. However, there was no long-term follow-up of these patients. The results of the other treatments were considered uncertain due to the high risk of bias. CONCLUSION: Considering the low quality of the studies included in the SRs, pharmacological treatment with antispasmodics and antidepressants seems to be beneficial for patients with IBS. Among non-pharmacological interventions, psychological interventions seem to be beneficial. However, further clinical trials are recommended with greater methodological rigor to prove these findings.

Rare single-nucleotide variants in oculo-auriculo-vertebral spectrum (OAVS).

BACKGROUND: Oculo-auriculo-vertebral spectrum (OAVS) is a craniofacial developmental disorder that affects structures derived from the first and second pharyngeal arches. The clinically heterogeneous phenotype involves mandibular, oral, and ear development anomalies. Etiology is complex and poorly understood. Genetic factors have been associated, evidenced by chromosomal abnormalities affecting different genomic regions and genes. However, known pathogenic single-nucleotide variants (SNVs) have only been identified in MYT1 in a restricted number of patients. Therefore, investigations of SNVs on candidate genes may reveal other pathogenic mechanisms. METHODS: In a cohort of 73 patients, coding and untranslated regions (UTR) of 10 candidate genes (CRKL, YPEL1, MAPK1, NKX3-2, HMX1, MYT1, OTX2, GSC, PUF60, HOXA2) were sequenced. Rare SNVs were selected and in silico predictions were performed to ascertain pathogenicity. Likely pathogenic variants were validated by Sanger sequencing and heritability was assessed when possible. RESULTS: Four likely pathogenic variants in heterozygous state were identified in different patients. Two SNVs were located in the 5'UTR of YPEL1; one in the 3'UTR of CRKL and one in the 3'UTR of OTX2. CONCLUSION: Our work described variants in candidate genes for OAVS and supported the genetic heterogeneity of the spectrum.

Quality of systematic reviews on the treatment of vesiculobullous skin diseases. A meta-epidemiological study

Abstract Background Systematic reviews of Randomized Controlled Trials (RCTs) are considered high-level evidence to support a decision on therapeutic interventions, and their methodological quality is essential to provide reliable and applicable results. Objective This meta-epidemiological study aimed to map and critically appraise systematic reviews assessing treatments for vesiculobullous skin diseases. Methods We conducted a comprehensive search strategy on MEDLINE (via Pubmed) in December 2022 without restrictions to find systematic reviews evaluating pharmacological interventions for vesiculobullous skin diseases. The methodological quality was assessed using the AMSTAR-2 tool, and additional information was extracted. We identified nine systematic reviews published between 2002 and 2021, seven assessing pemphigus. Results According to the AMSTAR-2 tool, 55.6% were classified as critically low quality, 22.2% as moderate quality, 11.1% as low and 11.1% as high quality. No review assessed the certainty of the evidence (GRADE); 86% of pemphigus reviews had at least two overlapping RCTs. There were some limitations regarding methodological flaws and the AMSTAR-2 tool use Conclusions These findings reveal a frail methodological quality of systematic reviews about vesiculobullous diseases treatment that may impact the results. Therefore, methodological rigor is mandatory for future systematic reviews to avoid duplication of effort and increase the certainty of the evidence supporting decision-making.

A novel de novo mutation in MYT1, the unique OAVS gene identified so far.

Oculo-auriculo-vertebral spectrum (OAVS) is a developmental disorder characterized by hemifacial microsomia associated with ear, eyes and vertebrae malformations showing highly variable expressivity. Recently, MYT1, encoding the myelin transcription factor 1, was reported as the first gene involved in OAVS, within the retinoic acid (RA) pathway. Fifty-seven OAVS patients originating from Brazil were screened for MYT1 variants. A novel de novo missense variant affecting function, c.323C>T (p.(Ser108Leu)), was identified in MYT1, in a patient presenting with a severe form of OAVS. Functional studies showed that MYT1 overexpression downregulated all RA receptors genes (RARA, RARB, RARG), involved in RA-mediated transcription, whereas no effect was observed on CYP26A1 expression, the major enzyme involved in RA degradation, Moreover, MYT1 variants impacted significantly the expression of these genes, further supporting their pathogenicity. In conclusion, a third variant affecting function in MYT1 was identified as a cause of OAVS. Furthermore, we confirmed MYT1 connection to RA signaling pathway.

Evidence from Cochrane systematic reviews on pharmacological treatment compared to placebo for panic disorder / Evidências das revisões sistemáticas cochrane sobre o tratamento farmacológico comparado ao placebo para transtorno de pânico

ABSTRACT. Panic disorder is an anxiety condition characterized by recurrent and unexpected panic attacks. The comparison between active treatment and placebo is essential to analyze an intervention's efficacy and safety. It is important to identify and summarize the studies with higher evidence to assist health professionals and public policy managers in clinical decision-making. Objective: The aim of this study was to identify and summarize all Cochrane systematic reviews (SRs) that compared the efficacy and safety of any drug treatment compared to placebo for panic disorder patients. Methods: SRs published in the Cochrane Library were included without date restriction. All outcomes presented were analyzed. The methodological quality of the SRs was evaluated using the AMSTAR-2 tool. Results: We included three Cochrane SRs of high methodological quality on the effects of antidepressants, benzodiazepines, and azapirones for panic disorder. All medications showed benefits in response to treatment, symptom improvement, and reduced panic attacks. Dropouts were lower with tricyclic antidepressants and benzodiazepines and higher with azapirones. The occurrence of adverse events was higher for drug groups. Conclusions: Very low to moderate certainty evidence (GRADE) showed that antidepressants and benzodiazepines seem to improve clinical symptoms in individuals with short-term panic disorder compared to placebo. In addition, the use of azapirones seems to have greater adherence by patients than placebo. However, there is insufficient evidence to support its clinical efficacy.

RESUMO. O transtorno de pânico é uma condição de ansiedade caracterizada por ataques de pânico recorrentes e inesperados. A comparação entre tratamento ativo e placebo é essencial para analisar a eficácia e a segurança de uma intervenção. É importante identificar os estudos com maiores evidências para auxiliar os profissionais de saúde e gestores de políticas públicas nas decisões clínicas. Objetivo: Identificar e sumarizar todas as revisões sistemáticas (RS) publicadas na Cochrane que relatam a eficácia e a segurança de qualquer tratamento medicamentoso comparado ao placebo para pacientes com transtorno de pânico. Métodos: Foram selecionadas e analisadas todas as RS publicadas na base de dados Cochrane, sem restrição de data. A qualidade metodológica das RS foi avaliada utilizando a ferramenta AMSTAR-2. Resultados: Foram incluídas três RS Cochrane com alta qualidade metodológica que avaliaram os efeitos de antidepressivos, benzodiazepínicos e azapironas para transtorno de pânico. Todos os medicamentos mostraram benefícios na resposta ao tratamento, melhora dos sintomas e redução das crises de pânico. O número de desistências do tratamento foi baixo com antidepressivos tricíclicos e benzodiazepínicos e alto com azapironas. A ocorrência de eventos adversos foi elevada para os grupos das medicações analisadas Conclusões: Evidências de certeza muito baixa a moderada (pela Classificação de Recomendações, Avaliação, Desenvolvimento e Análises - GRADE) mostraram que antidepressivos e benzodiazepínicos parecem melhorar os sintomas clínicos em indivíduos com transtorno de pânico em menor prazo, em comparação ao placebo. Além disso, o uso de azapironas parece ter maior adesão por parte dos pacientes do que o placebo. No entanto, não há evidências suficientes para comprovar sua eficácia clínica.

Position effect modifying gene expression in a patient with ring chromosome 14.

The clinical phenotype of patients with ring chromosomes usually reflects the loss of genomic material during ring formation. However, phenotypic alterations can also be found in the presence of complete ring chromosomes, in which the breakage and rejoining in terminal regions of both chromosome arms result in no gene loss. Here, we present a patient with a ring chromosome 14 that lost nothing but the telomeres. Since he and other patients with a similar chromosome abnormality present certain abnormal characteristics, we investigated the gene expression of eight chromosome 14 genes to find out whether the configuration of the ring had changed it, possibly producing some of these clinical features. The expression of these eight genes was studied by quantitative real-time polymerase chain reaction (qPCR) in the patient and in seven controls matched for gender and age. Two of them were found to be downregulated in the patient compared to the controls, indicating that his phenotype might be related to alterations in the expression of genes located in the abnormal chromosome, even when the copy number is normal. Thus, the phenotypic alterations found in the presence of complete ring chromosomes may be related to changes in the chromatin architecture, bringing about a change of expression by position effect. These results may explain some of the characteristics presented by our patient.

Intervenções para o tratamento da síndrome do intestino irritável: revisão de revisões sistemáticas Cochrane / Interventions for the treatment of irritable bowel syndrome: a review of cochrane systematic reviews

ABSTRACT BACKGROUND: Irritable bowel syndrome (IBS) is a complex gastrointestinal disorder, whose understanding is relatively uncertain, and the treatment guidance decision still represents a challenge. OBJECTIVE: To identify and critically appraise systematic reviews (SRs) published in the Cochrane Database of SRs (CDSR) on the effects of interventions (pharmacological and non-pharmacological) for the treatment of IBS. METHODS: The search was conducted at the Cochrane Library in May 2020. The methodological quality of the SRs was evaluated by the AMSTAR-2 tool. RESULTS: Eight SRs with moderate to high quality were included, which addressed the treatments: (a) pharmacological: volume agents, antispasmodics, antidepressants and tegaserod; and (b) non-pharmacological: homeopathy, acupuncture, phytotherapy, biofeedback, psychological interventions and hypnotherapy. The results were favorable to antispasmodic drugs and antidepressants regarding the improvement of clinical symptoms. There was no difference between volume agents or tegaserod when compared to placebo. Acupuncture and homeopathy showed a little improvement in symptoms compared to placebo, but the certainty of this evidence was considered low to very low. Psychological interventions seem to improve the overall assessment of the patient and relief symptoms such as abdominal pain. However, there was no long-term follow-up of these patients. The results of the other treatments were considered uncertain due to the high risk of bias. CONCLUSION: Considering the low quality of the studies included in the SRs, pharmacological treatment with antispasmodics and antidepressants seems to be beneficial for patients with IBS. Among non-pharmacological interventions, psychological interventions seem to be beneficial. However, further clinical trials are recommended with greater methodological rigor to prove these findings.

RESUMO CONTEXTO: A síndrome do intestino irritável (SII) é um distúrbio gastrointestinal complexo, cujo entendimento é relativamente incerto e a decisão de orientação do tratamento ainda representa um desafio. OBJETIVO: Identificar e avaliar criticamente as revisões sistemáticas (RSs) publicadas na base de dados de RSs Cochrane (CDSR) sobre os efeitos das intervenções (farmacológicas e não farmacológicas) para o tratamento da SII. MÉTODOS: A busca foi realizada na Biblioteca Cochrane em maio de 2020. A qualidade metodológica das RSs foi avaliada pela ferramenta AMSTAR-2. RESULTADOS: Foram incluídas oito RSs com qualidade moderada a alta, as quais abordaram os tratamentos: (a) farmacológico - agentes de volume, antiespasmódicos, antidepressivos e o tegaserod; e (b) não farmacológico - homeopatia, acupuntura, fitoterapia, biofeedback, intervenções psicológicas e hipnoterapia. Os resultados foram favoráveis aos medicamentos antiespasmódicos e antidepressivos em relação à melhora dos sintomas clínicos. Não houve diferença entre os agentes de volume ou tegaserod quando comparados ao placebo. Acupuntura e homeopatia apresentaram pequena melhora dos sintomas em comparação ao placebo, porém a qualidade da evidência foi considerada baixa a muito baixa. As intervenções psicológicas parecem melhorar a avaliação global do paciente e alívio de sintomas como dor abdominal. Contudo, não houve acompanhamento desses pacientes a longo prazo. Os resultados dos demais tratamentos foram considerados incertos devido ao alto risco de viés. CONCLUSÃO: Considerando a baixa qualidade dos estudos incluídos nas RSs, o tratamento farmacológico com antiespasmódicos e antidepressivos parece ser benéfico para os pacientes com SII. Entre os não-farmacológicos, as intervenções psicológicas parecem obter benefícios. Entretanto, novos ensaios clínicos são recomendados com maior rigor metodológico para comprovar estes achados.