Predominant monomorphism of the RIT2 and GPM6B exceptionally long GA blocks in human and enriched divergent alleles in the disease compartment

Across human protein-coding genes, the human neuron-specific genes, RIT2 and GPM6B, contain the two longest GA short tandem repeats (STRs) of 11 and 9-repeats, respectively, the length ranges of which are functional, and result in gene expression alteration. Here we sequenced the RIT2 and GPM6B STRs in 600 human subjects, consisting of late-onset neurocognitive disorder (n = 200), multiple sclerosis (n = 200), and controls (n = 200). Furthermore, we selected two large human databases, including the general-population-based gnomAD ( https://gnomad.broadinstitute.org ) and a mainly disease-phenotype-archiving database, TOPMed ( https://www.nhlbiwgs.org ), to compare allele frequencies in the general populations vs. the disease compartment. The RIT2 and GPM6B GA-repeats were monomorphic in the human subjects studied, at lengths of 11 and 9-repeats, respectively, and were predominantly human-specific in formula. Exception included a 9/11 genotype of the RIT2 GA-STR in an isolate case of female multiple sclerosis. Exceedingly rare alleles of the two GA repeats were significantly enriched in TOPMed vs. the gnomAD. We report prime instances of predominant monomorphism for specific lengths of STRs in human, and possible enrichment of rare divergent alleles in the disease phenotype compartment. While STRs are most attended because of their high polymorphic nature, STR monomorphism is an underappreciated feature, which may have a link with natural selection and disease.

A Review on Translucent Zirconia

INTRODUCTION

Zirconia is suggested in many clinical situations due to acceptable biocompatibility, lower price compared with gold restorations, and better appearance than traditional metal ceramic restorations. New translucent monolithic zirconia has been developed to merge strength with improved tooth-colour matching. This work aims to review relevant articles on new translucent zirconia restorative materials.

METHODS

The published articles on translucent zirconia were searched through PubMed, Medline, Google scholar, and indexed journals using the following keywords: translucent zirconia, transparent zirconia, and tooth colored zirconia. The most relevant articles were selected and reviewed.

RESULT

Introduction of translucent zirconia, has brought the advantages such as less tooth preparation, biological compatibility, high strength, good mechanical properties, and less antagonist wear. However, the effects of altering material constituents to increase translucency on properties such as phase transformation and low temperature degradation may warrant further investigations.

CONCLUSION

Translucent zirconia can be prescribed in many clinical situations and may provide less complicated procedures compared with the production of multilayer restorations of opaque zirconia cores and translucent feldspathic veneers. This may otherwise decrease fabrication time and defects, improve biological properties, reduce abutment tooth reduction, and result in less antagonist tooth attrition.