A Male Child with Infantile Epilepsy due to a Mosaic Missense Variant of PCDH19.

Background: Pathogenic variants of PCDH19, located on the X-chromosome (Xq22.1), cause a rare epileptic encephalopathy with speech and development delay, seizures, behavioral and psychiatric problems. The specific underlying pathogenic mechanism is known as "cellular interference" that results in affected heterozygous females, normal hemizygous males and affected mosaic males but its functioning is not yet clear. Objectives: Reporting new cases of affected males is considered useful to a deeper insight. Subject and Method: We present the case of a three-year-old boy with early-onset seizures at 3 months of age, mild cognitive impairment, partial control of seizures with levetiracetam, normal brain imaging. Results: The patient has a mosaic pathogenic variant c.698A>G (p.Asp233Gly) in PCDH19 assessed by Next Generation Sequencing analysis. We have compared his characteristics with the genotypes and phenotypes of 34 PCDH19 mosaic males earlier reported in the literature. Finally, we have summarized today's knowledge about phenotype-genotype correlation and pharmacological response in these patients. Conclusions: Our report confirms that the clinical picture of mosaic affected males, resembling that of females, can show a wide variability in severity of disease and underlines a stringent need to improve therapeutic approaches and to collect data on long-term follow-up.

Phenotypic Description of A Patient with ODLURO Syndrome and Functional Characterization of the Pathogenetic Role of A Synonymous Variant c.186G>A in KMT2E Gene.

O'Donnell-Luria-Rodan (ODLURO) syndrome is an autosomal dominant disorder caused by mutations in the KMT2E gene. The clinical phonotype of the affected individuals is typically characterized by global developmental delay, autism, epilepsy, hypotonia, macrocephaly, and very mild dysmorphic facial features. In this report, we describe the case of a 6-year-old boy with ODLURO syndrome who is a carrier of the synonymous mutation c.186G>A (p.Ala62=) in the KMT2E gene, predicted to alter splicing by in silico tools. Given the lack of functional studies on the c.186G>A variant, in order to assess its potential functional effect, we sequenced the patient's cDNA demonstrating its impact on the mechanism of splicing. To the best of our knowledge, our patient is the second to date reported carrying this synonymous mutation, but he is the first whose functional investigation has confirmed the deleterious consequence of the variant, resulting in exon 4 skipping. Additionally, we suggest a potential etiological mechanism that could be responsible for the aberrant splicing mechanism in KMT2E.

miRNA-221 and miRNA-483-3p Dysregulation in Esophageal Adenocarcinoma.

Alterations in microRNA (miRNA) expression have been reported in different cancers. We assessed the expression of 754 oncology-related miRNAs in esophageal adenocarcinoma (EAC) samples and evaluated their correlations with clinical parameters. We found that miR-221 and 483-3p were consistently upregulated in EAC patients vs. controls (Wilcoxon signed-rank test: miR-221 p < 0.0001; miR-483-3p p < 0.0001). Kaplan-Meier analysis showed worse cancer-related survival among all EAC patients expressing high miR-221 or miR-483-3p levels (log-rank p = 0.0025 and p = 0.0235, respectively). Higher miR-221 or miR-483-3p levels also correlated with advanced tumor stages (Mann-Whitney p = 0.0195 and p = 0.0085, respectively), and overexpression of miR-221 was associated with worse survival in low-risk EAC patients. Moreover, a significantly worse outcome was associated with the combined overexpression of miR-221 and miR-483-3p (log-rank p = 0.0410). To identify target genes affected by miRNA overexpression, we transfected the corresponding mimic RNA (miRVANA) for either miR-221 or miR-483-3p in a well-characterized esophageal adenocarcinoma cell line (OE19) and performed RNA-seq analysis. In the miRNA-overexpressing cells, we discovered a convergent dysregulation of genes linked to apoptosis, ATP synthesis, angiogenesis, and cancer progression, including a long non-coding RNA associated with oncogenesis, i.e., MALAT1. In conclusion, dysregulated miRNA expression, especially overexpression of miR-221 and 483-3p, was found in EAC samples. These alterations were connected with a lower cancer-specific patient survival, suggesting that these miRNAs could be useful for patient stratification and prognosis.