P485Re-interpretation of variants of uncertain significance in inherited cardiovascular diseases-A pilot study

Background- Identification of variants of uncertain significance (VUSs) poses relevant challenges in counseling and managing patients. They have an unknown impact on health, making the genetic tests clinically irrelevant. Recent studies demonstrate that a routine reclassification analysis enables to reclassify from 20% to 80% of this type of variant, improving risk stratification.

Purpose- We investigated whether, in the context of inherited cardiac conditions, a review of the updated literature, including new functional data, allele frequency (GnomAD) and segregation analysis may help in the variant reclassification.

Methods- Retrospective review of all VUSs in genes associated with inherited cardiac conditions identified in our cardiogenetic clinic between 2016 and 2018.

Results- Thirty-one VUSs, classified using ACMG guidelines, were identified in 26 cases with a confirmed or suspected diagnosis of inherited cardiovascular diseases, including Long QT syndrome, Brugada syndrome, Arrhythmogenic Cardiomyopathy and Hypertrophic Cardiomyopathy). Twentyfour variants were identified in well-defined causative genes (SCN5A, KCNQ1, KCNH2, KCNE1, DSP, DSG2, MYH7, TPM1, TNNI3, TNNT2, CACNA1C, MYL3) while the remaining variants were identified in minor genes with limited evidence to support their disease causation as, ANK2 and AKAP9 gene. Preliminary results of the reclassification analysis showed that two variants were downgraded to likely benign (LB) applying the BS1 criterion (allele frequency) and 4 variants were upgraded to likely pathogenic (LP) according to novel published data and family segregation studies. Moreover, further studies to assess cosegregation in other variants are still ongoing.

Conclusion- Based on our experience, 25% of variants of uncertain significance in well-defined causative genes, identified in patients with a confirmed or suspected diagnosis of inherited cardiovascular disease, were reclassified. These findings suggest that re-evaluation of genetic test results should be performed routinely in all diagnostic labs, in order to improve risk stratification and identification of family members at high risk.

Are optical indices good proxies of seasonal changes in carbon fluxes and stress-related physiological status in a beech forest?

This study investigates the functionality of a Mediterranean-mountain beech forest in Central Italy using simultaneous determinations of optical measurements, carbon (C) fluxes, leaf eco-physiological and biochemical traits during two growing seasons (2014-2015). Meteorological variables showed significant differences between the two growing seasons, highlighting a heat stress coupled with a reduced water availability in mid-summer 2015. As a result, a different C sink capacity of the forest was observed between the two years of study, due to the differences in stressful conditions and the related plant physiological status. Spectral indices related to vegetation (VIs, classified in structural, chlorophyll and carotenoid indices) were computed at top canopy level and used to track CO₂ fluxes and physiological changes. Optical indices related to structure (EVI 2, RDVI, DVI and MCARI 1) were found to better track Net Ecosystem Exchange (NEE) variations for 2014, while indices related to chlorophylls (SR red edge, CL red edge, MTCI and DR) provided better results for 2015. This suggests that when environmental conditions are not limiting for forest sink capacity, structural parameters are more strictly connected to C uptake, while under stress conditions indices related to functional features (e.g., chlorophyll content) become more relevant. Chlorophyll indices calculated with red edge bands (SR red edge, NDVI red edge, DR, CL red edge) resulted to be highly correlated with leaf nitrogen content (R²>0.70), while weaker, although significant, correlations were found with chlorophyll content. Carotenoid indices (PRI and PSRI) were strongly correlated with both chlorophylls and carotenoids content, suggesting that these indices are good proxies of the shifting pigment composition related to changes in soil moisture, heat stress and senescence. Our work suggests the importance of integrating different methods as a successful approach to understand how changing climatic conditions in the Mediterranean mountain region will impact on forest conditions and functionality.

Estrogens as antioxidant modulators in human fertility

Among treatments proposed for idiopathic male infertility, antiestrogens, like tamoxifen, play a possible role. On the other hand, oxidative stress is a mechanism well recognized for deleterious effects on spermatozoa function. After reviewing the literature on the effects of estrogens in modulation of antioxidant systems, in both sexes, and in different in vivo and in vitro models, we suggest, also on the basis of personal data, that a tamoxifen treatment could be active via an increase in seminal antioxidants.