Multinational experience with next-generation sequencing: opportunity to identify transthyretin cardiac amyloidosis and Fabry disease.

Background: Sarcomeric hypertrophic cardiomyopathy (HCM) must be differentiated from phenotypically similar conditions because clinical management and prognosis may greatly differ. Patients with unexplained left ventricular hypertrophy require an early, confirmed genetic diagnosis through diagnostic or predictive genetic testing. We tested the feasibility and practicality of the application of a 17-gene next-generation sequencing (NGS) panel to detect the most common genetic causes of HCM and HCM phenocopies, including treatable phenocopies, and report detection rates. Identification of transthyretin cardiac amyloidosis (ATTR-CA) and Fabry disease (FD) is essential because of the availability of disease-specific therapy. Early initiation of these treatments may lead to better clinical outcomes. Methods: In this international, multicenter, cross-sectional pilot study, peripheral dried blood spot samples from patients of cardiology clinics with an unexplained increased left ventricular wall thickness (LVWT) of ≥13 mm in one or more left ventricular myocardial segments (measured by imaging methods) were analyzed at a central laboratory. NGS included the detection of known splice regions and flanking regions of 17 genes using the Illumina NextSeq 500 and NovaSeq 6000 sequencing systems. Results: Samples for NGS screening were collected between May 2019 and October 2020 at cardiology clinics in Colombia, Brazil, Mexico, Turkey, Israel, and Saudi Arabia. Out of 535 samples, 128 (23.9%) samples tested positive for pathogenic/likely pathogenic genetic variants associated with HCM or HCM phenocopies with double pathogenic/likely pathogenic variants detected in four samples. Among the 132 (24.7%) detected variants, 115 (21.5%) variants were associated with HCM and 17 (3.2%) variants with HCM phenocopies. Variants in MYH7 (n=60, 11.2%) and MYBPC3 (n=41, 7.7%) were the most common HCM variants. The HCM phenocopy variants included variants in the TTR (n=7, 1.3%) and GLA (n=2, 0.4%) genes. The mean (standard deviation) ages of patients with HCM or HCM phenocopy variants, including TTR and GLA variants, were 42.8 (17.9), 54.6 (17.0), and 69.0 (1.4) years, respectively. Conclusions: The overall diagnostic yield of 24.7% indicates that the screening strategy effectively identified the most common forms of HCM and HCM phenocopies among geographically dispersed patients. The results underscore the importance of including ATTR-CA (TTR variants) and FD (GLA variants), which are treatable disorders, in the differential diagnosis of patients with increased LVWT of unknown etiology.

Profile of children assisted in a teaching outpatient clinic of developmental disabilities in São Paulo, Brazil.

OBJECTIVE: To analyze the epidemiological and clinical profile of patients with developmental disabilities followed in a university clinic in Brazil. METHODS: Descriptive, retrospective study, based on medical records. Children aged zero to 18 years with developmental problems, firstly evaluated between 2009 and 2018, were included. Patients with missing data or out of the age and time period established were excluded. There were nine losses and 374 patients constituted the final sample. Linear regression models were performed. RESULTS: The mean age at the first assessment was 52.2±39.7 months and the age when the parents perceived the symptoms was 20.9±23.8 months. The most common impairment was motor associated with language delay (28.3%). The interval between the parents' perception and the first consultation was associated with the mothers' education and number of pregnancies. The age at first assessment was associated with the disability type. The number of pregnancies was associated with the child's age when the parents noticed the symptoms and at the first consultation. CONCLUSIONS: Parents' recognition of the symptoms occurred early, however, there was a delay until the arrival at the clinic. Higher maternal education was associated with a shorter gap between perception of the developmental disability and consultation. A greater number of pregnancies was associated with a later perception of the developmental delay by the parents as well as a delay in the assessment and a wider interval between them. Motor problems were the most common in younger children, and language complaints in older ones.

Profile of children assisted in a teaching outpatient clinic of developmental disabilities in São Paulo, Brazil / Perfil das crianças atendidas em um ambulatório de ensino de alterações do desenvolvimento em São Paulo, Brasil

Abstract Objective: To analyze the epidemiological and clinical profile of patients with developmental disabilities followed in a university clinic in Brazil. Methods: Descriptive, retrospective study, based on medical records. Children aged zero to 18 years with developmental problems, firstly evaluated between 2009 and 2018, were included. Patients with missing data or out of the age and time period established were excluded. There were nine losses and 374 patients constituted the final sample. Linear regression models were performed. Results: The mean age at the first assessment was 52.2±39.7 months and the age when the parents perceived the symptoms was 20.9±23.8 months. The most common impairment was motor associated with language delay (28.3%). The interval between the parents' perception and the first consultation was associated with the mothers' education and number of pregnancies. The age at first assessment was associated with the disability type. The number of pregnancies was associated with the child's age when the parents noticed the symptoms and at the first consultation. Conclusions: Parents' recognition of the symptoms occurred early, however, there was a delay until the arrival at the clinic. Higher maternal education was associated with a shorter gap between perception of the developmental disability and consultation. A greater number of pregnancies was associated with a later perception of the developmental delay by the parents as well as a delay in the assessment and a wider interval between them. Motor problems were the most common in younger children, and language complaints in older ones.

Resumo Objetivo: Estabelecer o perfil clínico-epidemiológico de pacientes com alterações do desenvolvimento acompanhados em uma clínica universitária brasileira. Métodos: Estudo descritivo, retrospectivo, baseado em prontuários. Foram incluídas crianças de zero a 18 anos com alterações do desenvolvimento, primeiramente avaliadas entre 2009 e 2018. Foram excluídos pacientes com dados ausentes ou fora da idade e do período estabelecidos. Houve nove perdas, e 374 pacientes constituíram a amostra final. Modelos de regressão linear foram executados. Resultados: A média de idade na primeira avaliação foi de 52,2±39,7 meses, e a média de idade quando os pais perceberam os sintomas foi de 20,9±23,8 meses. O comprometimento mais comum foi o motor associado ao da linguagem (28,3%). O intervalo entre a percepção dos pais e a primeira consulta esteve associado à escolaridade materna e ao número de gestações. A idade da primeira avaliação foi relacionada ao tipo de comprometimento. O número de gestações foi associado à idade da criança quando os pais notaram os sintomas e na primeira consulta. Conclusões: O reconhecimento dos sintomas pelos pais foi pontual, porém houve demora até a chegada à clínica. Maior escolaridade materna foi associada a menor defasagem entre a percepção da deficiência e a consulta. Maior número de gestações foi associado a uma percepção tardia dos pais com relação aos sintomas e ao atraso na primeira avaliação, bem como ao maior intervalo entre elas. Os sintomas motores foram os mais comuns nas crianças mais novas, e as queixas de linguagem nas mais velhas.

A novel variant in the COX15 gene causing a fatal infantile cardioencephalomyopathy: A case report with clinical and molecular review.

The cytochrome c-oxidase (COX) enzyme, also known as mitochondrial complex IV (MT-C4D), is a transmembrane protein complex found in mitochondria. COX deficiency is one of the most frequent causes of electron transport chain defects in humans. Therefore, high energy demand organs and tissues are affected in patients with mutations in the COX15 gene, with variable phenotypic expressiveness. We describe the case of a male newborn with hypertrophic cardiomyopathy and serum and cerebrospinal fluid hyperlacticaemia, whose exome sequencing revealed two variants in a compound heterozygous state: c.232G > A; p.(Gly78Arg), classified as likely pathogenic, and c.452C > G; p.(Ser151Ter), as pathogenic; the former never previously described in the literature.

Leigh syndrome in a patient with a novel C12orf65 pathogenic variant: case report and literature review.

Leigh syndrome is an early onset progressive disorder caused by defects in mitochondrial oxidative phosphorylation. Pathogenic variants in nuclear and mitochondrial genes are associated with the syndrome. Homozygous pathogenic variants in the C12orf65 gene impair the mitochondrial oxidative phosphorylation system. We describe a new case of Leigh syndrome caused by a novel pathogenic variant of the C12orf65 gene resulting in the lack of the Gly-Gly-Gln (GGQ) domain in the predicted protein, and review clinical and molecular data from previously reported patients. Our study supports that the phenotype caused by C12orf65 gene variants is heterogeneous and varies from spastic paraparesis to Leigh syndrome. Loss-of-function variants are more likely to cause the disease, and variants affecting the GGQ domain tend to be associated with more severe phenotypes, reinforcing a possible genotype-phenotype correlation.

Congenital afibrinogenemia in a patient with vascular abnormalities and a novel variant: clinical-molecular description and literature review.

: The objective is to report a patient with congenital afibrinogenemia and vascular abnormalities and also review the clinical and molecular issues. The female proband, diagnosed with congenital afibrinogenemia, was admitted at a hospital due to a hemorrhagic shock. Angiotomography revealed ectasias from ascending branch to the abdominal aorta, with multiple calcifications and atheroma. Clinical exome identified a homozygous novel pathogenic variant in FGG gene. In our review the main symptom, at diagnosis, was umbilical cord bleeding and the degree of clinical involvement varied from asymptomatic to severe. The FGA gene was the most affected and possible hot spots were observed. Variants considered as loss of function were the most frequent. The association of vascular abnormalities in a patient with congenital afibrinogenemia alerts for a closer follow-up of vascular issues in these patients.

Mutational and oxidative stress analysis in patients with mucopolysaccharidosis type I undergoing enzyme replacement therapy.

BACKGROUND: Mucopolysaccharidosis type I (MPS I) patients present a wide range of clinical manifestations, which could be due to the high molecular heterogeneity of the IDUA gene and to pathological events besides the enzyme deficiency. The aim of this study was to identify the most common MPS I causing mutations and to evaluate some oxidative stress markers in Brazilian patients. METHODS: 3 common mutations in the IDUA gene were searched in 11 MPS I patients by PCR-RFLP. Activities of antioxidant enzymes catalase and superoxide dismutase, and levels of total glutathione and thiobarbituric acid reactive substances were evaluated by spectrophotometric and colorimetric methods, during different periods of enzyme replacement therapy. RESULTS: The most common mutations were P533R and W402X, with allelic frequencies of 33.33% and 27.8% respectively. MPS I patients presented high levels of lipid peroxidation and enzyme replacement therapy led to an increase of catalase and a decrease of superoxide dismutase activities. CONCLUSIONS: P533R and W402X accounted for more than 60% of the alleles, but no genotype-phenotype correlation could be established. The alterations in antioxidant enzyme activities suggest that oxidative stress may be an important event among MPS I patients, which could contribute to the physiopathology of the disease.

Blood oxidative stress markers in Gaucher disease patients.

BACKGROUND: Gaucher disease (GD) is the most common glycosphingolipidosis resulting in accumulation of glucoceramide. The most effective treatment for this disease is enzyme replacement therapy (ERT) which involves recombinant enzyme infusion. Enzymatic deficiency in GD patients may induce a cascade of events culminating in secondary effects such as the production of reactive oxygen species (ROS). We investigated the relationship between ROS and GD by analyzing blood oxidative stress markers in GD patients submitted to ERT at different stages during the treatment. METHODS: Blood were collected before and just after enzyme infusion. Red blood cell catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) and total glutathione (tGSH), and plasma thiobarbituric acid reactive substances (TBARS) were assayed by spectrophotometry. Homocysteine concentrations and related polymorphisms were also studied. Control individuals matched for sex and age were also analyzed. RESULTS: Concentrations of homocysteine and TBARS, and GPx enzyme activity were not different in ERT-treated GD patients. CAT activity was higher while SOD was lower in patients compared to controls. No variations in any of these parameters were found before and just after ERT. Regarding tGSH, a significant increase was observed in GD patients after infusion. Genotypic frequencies studied did not differ from controls or other Brazilian samples. CONCLUSION: ERT-treated GD patients show an improvement in antioxidant capacity, which is further increased just after recombinant enzyme infusion.

Molecular analysis of homocystinuria in Brazilian patients.

BACKGROUND: Cystathionine beta-synthase (CBS) deficiency is the most common cause of homocystinuria. However, no data are available concerning the molecular basis of this disease in Brazilian populations. METHODS: We studied 14 Brazilian patients from 11 unrelated families using a combined screening approach, involving restriction analysis, single-strand conformational polymorphism (SSCP) scanning, and sequencing. RESULTS: All patients presented homocysteine levels higher than 200 mumol/l before the beginning of treatment. The most common CBS gene mutations, p.G307S (c.919G > A) and p.I278T (c.833T > C), were evaluated and the allele c.919A was not found. One allele with the c.844 ins68 (4.5%) in the CBS gene was found. Three families (6 patients) presented the allele c.833 C (13.6%), without the insertion in the heterozygous state. SSCP scanning and sequencing showed 3 alleles p.T191M (13.64%) in 2 families. One allele with a novel mutation was found in exon 4 (c.168T > A) of the CBS gene (4.5%). We also analyzed c.677C > T and c.1298A > C polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and the 2756A > G polymorphism in the methionine synthase (MTR) gene. The frequencies of mutated alleles were: 50% c.677T and 18.2% c.1298C for MTHFR, and 27.3% c.2756G for MTR. CONCLUSION: In spite of the high level of racial mixing in the country, Brazilian homocystinuric patients did not present a high prevalence of the most common mutations described in the literature.

Menkes disease: case report of an uncommon presentation with white matter lesions

Menkes disease is a rare X-linked disorder related to a defect in the copper metabolism. According to the current literature, the most frequent neuroimaging findings are cortical atrophy, chronic subdural effusion or hygroma, and vascular abnormalities. White matter lesions may be present before other features of the disease and may evolve into atrophy. We hereby report a case of Menkes disease with typical history and progression, and an early phase imaging study with important white matter abnormalities, which could have lead to diagnostic difficulties