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Background: Isoleucinyl‐tRNA synthetase (IARS) is encoded by the IARS1 gene and catalyzes the binding of isoleucine to specific tRNA. Objective: This study aims to investigate the pathogenicity of novel IARS1 variants and the genotype–phenotype association, in order to expand the spectrum of pathogenic variants and phenotypes of IARS1‐related disease and provide new evidence for the phenotypic spectrum of IARS1 variants. Methods: Clinical data of the proband were collected, and trio whole‐exome sequencing (WES) was performed on the proband and the parents. Candidate variants were validated using Sanger sequencing. Bioinformatics software was utilized to analyze the functional consequences of identified variants and predict their potential deleteriousness. Results: A 17‐month‐old female patient presented with microcephaly, left external ear malformation, decreased muscle strength and tone in all limbs, epileptic seizures, global developmental delay, and developmental regression. Trio WES identified compound heterozygous variants in the IARS1 gene, c.120‐1G>A and c.2164C>A, which were novel pathogenic and likely pathogenic variants, respectively. The phenotype of developmental regression has not been reported before. Only one patient with IARS1 compound heterozygous variants has been reported in the world to have an epileptic phenotype, and this is the second patient with an epileptic phenotype. Bioinformatics analysis revealed that the splicing variant disrupted the canonical splice donor site, while the missense variant altered the local electrostatics of the IARS1 protein surface, potentially leading to functional abnormalities. Conclusion: This study identified novel IARS1 variants and the phenotype of developmental regression, expanding the spectrum of pathogenic variants and phenotypes of IARS1‐related diseases and providing new evidence for the rare phenotype of epileptic seizures caused by IARS1 variants. [ABSTRACT FROM AUTHOR]

Background The association between different phenotypes and genotypes of circulating tumor cells (CTCs) and efficacy of neoadjuvant chemotherapy (NAC) remains uncertain. This study was conducted to evaluate the relationship of FTH1 gene-associated CTCs (F-CTC) with/without epithelial-mesenchymal transition (EMT) markers, or their dynamic changes with the efficacy of NAC in patients with non-metastatic breast cancer. Patients and Methods This study enrolled 120 patients with non-metastatic breast cancer who planned to undergo NAC. The FTH1 gene and EMT markers in CTCs were detected before NAC (T0), after 2 cycles of chemotherapy (T1), and before surgery (T2). The associations of these different types of CTCs with rates of pathological complete response (pCR) and breast-conserving surgery (BCS) were evaluated using the binary logistic regression analysis. Results F-CTC in peripheral blood ≥1 at T0 was an independent factor for pCR rate in patients with HER2-positive (odds ratio [OR]=0.08, 95% confidence interval [CI], 0.01-0.98, P =.048). The reduction in the number of F-CTC at T2 was an independent factor for BCS rate (OR = 4.54, 95% CI, 1.14-18.08, P =.03). Conclusions The number of F-CTC prior to NAC was related to poor response to NAC. Monitoring of F-CTC may help clinicians formulate personalized NAC regimens and implement BCS for patients with non-metastatic breast cancer. [ABSTRACT FROM AUTHOR]