Background/Objectives: The RET (Rearranged during Transfection) gene encodes a receptor tyrosine kinase. RET plays a critical role in embryonic development and postnatal physiology. This review provides a comprehensive overview of RET-associated disorders, focusing on the molecular mechanisms of RET activation, associated clinical phenotypes and therapeutic implications. In addition, we present an updated RET mutation database. Methods: RET mutation database is built through the integration and curation of data from two major RET mutation repositories: the Leiden Open Variation Database (LOVD) and the Cancer Knowledge Base (CKB) as well as information derived from the ClinVar database. Results: To date, 78 pathogenic RET mutations have been identified, among these, 71 (91.0%) are single nucleotide substitutions (missense variants), 2 (2.6%) are deletions, 1 (1.3%) are indels, 2 (2.6%) are nonsense mutations and 1 (1.3%) mutation affecting the introns. A pronounced clustering was observed in exons 10–11, accounting for ~60% of cases, suggesting a potential mutational hotspot with structural or functional relevance. Conclusions: Aberrant RET activation, resulting from activating missense variants, gene fusions, or overexpression, underlies a wide spectrum of human diseases. These include multiple endocrine neoplasia type 2A (MEN2A), medullary thyroid carcinoma (MTC), Hirschsprung disease, and pheochromocytoma. The existence and use of a database classifying variants in the RET gene plays a fundamental role in molecular diagnostics and personalized medicine.

Background: Copy number variations (CNVs), also referred to as large genomic rearrangements (LGRs), represent a crucial component of BRCA1/2 (BRCA) testing. Next-generation sequencing (NGS) has become an established approach for detecting LGRs by combining sequencing data with dedicated bioinformatics pipelines. However, CNV detection in formalin-fixed paraffin-embedded (FFPE) samples remains technically challenging, and there is the need to implement a robust and optimized analysis strategy for routine clinical practice. Methods: This study evaluated 40 FFPE ovarian cancer (OC) samples from patients undergoing BRCA testing. The performance of the amplicon-based NGS Diatech Myriapod^® NGS BRCA1/2 panel (Diatech Pharmacogenetics, Jesi, Italy) was assessed for its ability to detect BRCA CNVs and results were compared to two hybrid capture-based reference assays. Results: Among the 40 analyzed samples (17 CNV-positive and 23 CNV-negative for BRCA genes), the Diatech pipeline showed a good concordance with the reference method—all CNVs were correctly identified in 16 cases with good enough sequencing quality. Only one result was inconclusive due to low sequencing quality. Conclusions: These findings support the clinical utility of NGS-based CNV analysis in FFPE samples when combined with appropriate bioinformatics tools. Integrating visual inspection of CNV plots with automated CNV calling improves the reliability of CNV detection and enhances the interpretation of results from tumor tissue. Accurate CNV detection directly from tumor tissue may reduce the need for additional germline testing, thus shortening turnaround times. Nevertheless, blood-based testing remains mandatory to determine whether detected BRCA CNVs are of hereditary or somatic origin, particularly in cases with a strong clinical suspicion of inherited predisposition due to young age and a personal and/or family history of OC.

Background: Copy number variations (CNVs), also referred to as large genomic rearrangements (LGRs), represent a crucial component of BRCA1/2 (BRCA) testing. Next-generation sequencing (NGS) has become an established approach for detecting LGRs by combining sequencing data with dedicated bioinformatics pipelines. However, CNV detection in formalin-fixed paraffin-embedded (FFPE) samples remains technically challenging, and it cannot always be guaranteed that such in-formation will be reliably obtained. Therefore, optimization is needed, and implementing a robust analysis strategy for routine clinical practice could provide significant advantages. Methods: This study evaluated 40 FFPE ovarian cancer (OC) samples from patients undergoing BRCA testing. The performance of the amplicon-based NGS Diatech Myriapod® NGS BRCA1/2 panel (Diatech Pharmacogenetics, Jesi, Italy) was assessed for its ability to detect BRCA CNVs, and results were compared to two hybrid capture-based reference assays. Results: Among the 40 analyzed samples (17 CNV-positive and 23 CNV-negative for BRCA genes), the Diatech pipeline showed high concordance with the reference methods. In a clinical di-agnostic setting, the evaluated method achieved an overall accuracy of about 96%, with a sensitivity of 94% and specificity of 96%. Despite one inconclusive result due to low sequencing quality and one sample with a somatic CNV in BRCA1 that was not detected, the Diatech Myriapod® NGS BRCA1/2 panel kit demonstrated strong potential for routine clinical application in CNV detection from FFPE tissue. Conclusions: These findings support the clinical utility of NGS-based CNV analysis in FFPE sam-ples when combined with appropriate bioinformatics tools. Integrating visual inspection of CNV plots with automated CNV calling improves the reliability of CNV detection and enhances the in-terpretation of results from tumor tissue. Accurate CNV detection directly from tumor tissue may reduce the need for reflex germline testing and improve turnaround times. Nevertheless, blood-based testing remains essential to determine whether detected BRCA CNVs are of germline or so-matic origin, particularly in cases with a strong clinical suspicion of a germline CNV.

Keywords: Cystic fibrosis, Cystic Fibrosis Transmembrane Conductance Regulator gene, CFTR, Next Generation Sequencing, Cystic fibrosis carriers

Next Generation Sequencing (NGS), now widely used in the clinical setting, offers an efficient and comprehensive molecular approach for patients with Familial hypercholesterolemia (FH). Although the dominant form of disease is mostly due to low-density lipoprotein receptor (LDLR) small-scale pathogenic variants, approximately 10% of molecularly defined FH cases are due to Copy Number Variations (CNVs). Here, we report a novel large deletion of the LDLR gene involving exons 4–18, identified by bioinformatic analysis of NGS data in an Italian family. A long PCR strategy was employed for breakpoint region analysis where an insertion of 6 nucleotides (TTCACT) was found. Two Alu sequences, identified within intron 3 and exon 18, could underlie the identified rearrangement by a Nonallelic Homologous Recombination (NAHR) mechanism. NGS proves to be a powerful tool used to precisely identify CNVs, in addition to small-scale variants in FH-related genes. At this purpose, the use and implementation of this cost-effective, efficient molecular approach meets the clinical need for personalized diagnosis in FH cases.

Background: G6PD is a rate-limiting enzyme of the pentose phosphate pathway. The loss of G6PD activity in red blood cells exposes to the risk of acute haemolytic anaemia under oxidative stress, induced by infections, some medications, or fava beans. More than 200 single missense mutations are known in the G6PD gene. This study reports a 41-year-old woman coming from Basilicata region (Italy) that carried out the G6PD status in our hospital for prenatal investiga-tions. Methods: DNA was extracted from peripheral blood sample and genotyped for common-est G6PD pathogenic variants (PVs). Positive results obtained by Restriction Fragment Length Polymorphism (RFLP), as per practice in our laboratory, are then re-confirmed in Sanger se-quencing. Results: RFLP analysis highlighted a variant compatible with G6PD Cassano variant. Confirmatory testing by Sanger unexpectedly identified a novel variant: c.1357G>A, p.(Val453Met) (NM_001360016.2). In silico models predicted a deleterious effect of this variant at the protein level. The novel G6PD variant was named "G6PD Potenza", on the basis of the pa-tient's regional origin. Conclusion: This case describes a novel G6PD variant. It also highlights how the Sanger sequencing technique still represents an indispensable confirmatory standard method for variants that could be miss-interpreted by using of “first-level” approached, as the RFLP. We stress that the evaluation of clinical manifestations in G6PD deficient patients is of primary importance for the classification of each new G6PD mutation, in agreement with the new WHO guidelines.