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Autism spectrum disorder (ASD) is a neurological condition that directly affects brain functions and can culminate in delayed intellectual development, problems in verbal communication, difficulties in social interaction, and stereotyped behaviors. Its etiology reveals a genetic basis that can be strongly influenced by socio-environmental factors. Ion channels controlled by ligand voltage-activated calcium, sodium, and potassium channels may play important roles in modulating sensory and cognitive responses, and their dysfunctions may be closely associated with neurodevelopmental disorders such as ASD. This is due to ionic flow, which is of paramount importance to maintaining physiological conditions in the central nervous system and triggers action potentials, gene expression, and cell signaling. However, since ASD is a multifactorial disease, treatment is directed only to secondary symptoms. Therefore, this research aims to gather evidence concerning the principal pathophysiological mechanisms involving ion channels in order to recognize their importance as therapeutic targets for the treatment of central and secondary ASD symptoms.

Background and aims GPIHBP1 is an accessory protein of lipoprotein lipase (LPL) essential for its functioning. Mutations in the GPIHBP1 gene cause a deficit in the action of LPL, leading to severe hypertriglyceridemia and increased risk for acute pancreatitis. Methods We describe twelve patients (nine women) with a novel homozygous mutation in intron 2 of the GPIHBP1 gene. Results All patients were from the Northeastern region of Brazil and presented the same homozygous variant located in a highly conserved 3′ splicing acceptor site of the GPIHBP1 gene. This new variant was named c.182-1G > T, according to HGVS recommendations. We verified this new GPIHBP1 variant's effect by using the Human Splicing Finder (HSF) tool. This mutation changes the GPIHBP1 pre-mRNA processing and possibly causes the skipping of the exon 3 of the GPIHBP1 gene, affecting almost 50% of the cysteine-rich Lys6 GPIHBP1 domain. Patients presented with severe hypertriglyceridemia (2351 mg/dl [885–20600]) and low HDL (18 mg/dl [5–41). Four patients (33%) had a previous history of acute pancreatitis. Conclusions We describe a novel GPIHBP1 pathogenic intronic mutation of patients from the Northeast region of Brazil, suggesting the occurrence of a founder effect.

10594 Background: As germline testing in BC is becoming more accessible, a large body of evidence from distinct populations is revealing different prevalence of affected genes or recurrent and founder mutations. We evaluated a series of Brazilian BC patients from diverse regions of the country that were studied in a single laboratory facility for likely pathogenic/pathogenic variants (PV) and variants of unknown significance (VUS) in BRCA1/2 and other BC susceptibility genes (ATM, BARD1, CDH1, CHEK2, PALB2, RAD51C, RAD51D and TP53). Methods: We used multi-gene NGS panels covering from 35 to 105 genes, including copy number alterations, to perform sequencing in patients with diagnosis of BC from 2016 to 2021. With patient consent, we extracted clinical and pathological data from curated Real-World Database of Oncoclínicas Group to classify tumors according to hormone receptor (HR) and HER2 status and assess family history of cancer. Primary endpoint was prevalence of PV and VUS in BRCA1/2 and other breast cancer risk genes. Results: In total, 1,520 patients with BC were included in the analysis, 99% were female, median age at genetic testing was 46 years and 84% had family history of cancer. BC subtype was available in 717 cases (43% HR+/HER2-, 26% HER2+, 31% triple negative). Median age at genetic testing in HR+/HER2- population was 49 years and 44 years in HER2+ and triple-negative cases. Overall, 11.7% (CI95% 10.1-13.4) of the population had at least one PV in any BC risk gene: 50 in BRCA1, 49 in BRCA2, 22 in TP53 (17 had Brazilian founder p.R337H haplotype), 19 in PALB2, 18 in CHEK2, 15 in ATM, 7 in other genes (BARD1, CDH1, RAD51C, RAD51D) and 4 patients had co-existing PV in 2 BC risk genes. BRCA1/2 PVs were found in 7% of BC patients and BRCA1/2 VUS in 3%, being higher in triple-negative cases (11% PVs) than HR+/HER2- (5% PVs) and HER2+ (3%). For other BC risk genes, 5% of the patients had a PV, without differences according to BC subtype, and the prevalence of VUS was 14%. The prevalence of TP53 Brazilian founder mutation in BC was 1.2%. Median age of genetic testing was younger in population with BRCA1 PV (43 years) than BRCA2 PV (47 years) and other genes PV (46 years). Conclusions: In this real-world cohort of BC patients enriched for high-risk features such as young age at diagnosis, positive family history and triple-negative disease, the prevalence of BRCA1 and BRCA2 PV was very similar and represented only 56% of all PV detected. Different from other studies, TP53 mutations are the third most common germline alteration in the Brazilian population, with close to 80% of the cases presenting the founder mutation p.R337H. BC with epidemiologic high-risk features should be offered a germline test in Brazilian patients due to the considerable chance of a PV detection.

Introduction: Pompe’s disease is a neuromuscular condition caused by a metabolic disorder of autosomal recessive inheritance. The deficit of acid alpha-glucosidase causes accumulation of glycogen in the lysosomes of the striated and cardiac muscle. It presents in childhood: hypotonia and cardiorespiratory impairment; but at late-onset: axial and waist muscle weakness. Case report: Patient, female, 20 years old, non-consanguineous parents, with good intra-uterus fetal mobility, was born by cesarean delivery weighing 3.7 kilograms and 51 centimeters. She first walked without support and spoke her first words at 13 months of age. By the age of 12, she started progressive thoracolumbar scoliosis and underwent posterior spinal arthrodesis two years later. During the follow-up, muscle weakness was found. Furthermore, she presented macrocephaly, high myopia, fusion of cervical vertebrae, progressive scoliosis, dolichostenomelia and joint hypermobility. Extensive investigation was carried out with laboratory tests that showed CPK elevation, imaging tests and mutation research for facio-scapular-humeral muscular dystrophy and type 2A waistband muscular dystrophy. The incisional biopsy found mixed muscle changes with deposit of amorphous material. Pompe’s disease was confirmed by a significant reduction in alpha-glucosidase activity. The patient evolved with weakness in the legs and fatigue on moderate efforts, but also weakness in the lower limbs, detachable on the right and hyporeflexia, on physical examination. Conclusions: Progressive thoracolumbar scoliosis, refractory to postural and surgical corrections, should be an alert for differential diagnoses. Changes in axial musculature can be suggested and Pompe’s disease, a potentially treatable condition, must become relevant.