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: 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.

Background: Glucose 6 phosphate dehydrogenase (G6PD) is a rate-limiting enzyme of the pentose phosphate pathway. The loss of G6PD activity in red blood cells increases 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. A 41-year-old woman with a family history of favism coming from the Basilicata region (Italy) was evaluated at our hospital for G6PD abnormalities. Methods: DNA was extracted from a peripheral blood sample and genotyped for the most common G6PD pathogenic variants (PVs). Positive results obtained by Restriction Fragment Length Polymorphism (RFLP), as per practice in our laboratory, were then reconfirmed in Sanger sequencing. Results: RFLP analysis highlighted a variant compatible with the G6PD Cassano variant. Confirmatory testing by Sanger unexpectedly identified a novel variant: c.1357G>A, p.(Val453Met) (NM_001360016.2); the same variant was found in the patient’s mother. 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 patient’s regional origin. Conclusions: 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 misinterpreted by only using a “first-level” approach, such 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.