# Genetic Variants in Patients with Premature Ovarian Insufficiency in a Mexican Cohort
## 4 Discussion  
The present study revealed 13 single-nucleotide variants (SNVs), and to the best of our knowledge, seven of them are reported for the first time (_WT1_ (c.609T>C, c.873A>G, c.1122G>A), _NR0B1_ (c.353C>T, c.425G>A), _NR5A1_ (c.437G>C: rs1110061, IVS4-20C>T), _LHX9_ (IVS2-12G>C: rs12122995, IVS3+13C>T: rs13376365, c.741T>C: rs12046958), _ZNF275_ (c.969C>T), and _NRIP1_ (c.3403C>T: rs61750207)). Five were novel synonymous SNVs (sSNVs), one was a novel non-synonymous SNV (nsSNV), and one a novel non-coding SNV (ncSNV) (Table 1); these sSNVs were not found in the catalogue of common human genetic variations (1000 Genomes Project: [[https://www.ncbi.nlm.nih.gov/variation/tools/1000](https://www.ncbi.nlm.nih.gov/variation/tools/1000) genomes/]([https://www.ncbi.nlm.nih.gov/variation/tools/1000](https://www.ncbi.nlm.nih.gov/variation/tools/1000) genomes/), accessed on 1 March 2022 and Genome Aggregation Database: [[https://gnomad.broadinstitute.org/](https://gnomad.broadinstitute.org/)]([https://gnomad.broadinstitute.org/](https://gnomad.broadinstitute.org/)), accessed on 1 March 2022). Theoretical and experimental evidence supports the non-neutrality of synonymous alleles or sSNVs in animals and the human population [35; 36]. Examples of functionality associated with synonymous sites include maximized translational efficiency, optimized mRNA stability, and efficient splicing control. In pigs, the c.258G>A synonymous mutation alters _IGF1_ gene expression and affects IGF1 folding and its interactions with the IGF1R [37]. [PERSON] et al. [38] reported that the c.2562T>G; p.7854 = sSNV induced local changes in translation velocity, giving rise to more stable channels with a greatly reduced single-channel conductance. A synonymous coding variant c.1437G>C/p.Arg479 = was reported in patients with X-linked sideroblastic anemia (XLSA), where the _ALAS2_ mRNA transcribed from the c.1437C allele is spliced less efficiently and/or degraded via nonsense-mediated decay [39]. A synonymous coding base change was identified in the mRNA splicing site of the _CYP21A2_ gene. The novel pathogenic variant c.116C>T; p.Ser372 = is associated with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency [40]. Moreover, a pathogenic synonymous variant p.Ser324 = (c.972G>A) in the _SLC2A1_ gene is associated with paroxysmal exercise-induced dyskinesia [41]. Despite these findings, no relationship was found between the seven genotypic synonymous variants identified in this study (sSNVs in the _WT1_ ((c.213G>T; p.P71=), (c.609T>C; p.N203=), (c.873A>G; p.R291=), and (c.1122 G>A; p.R374=)), _NR0B1_ (c.498G>A; p.R166=), and _ZNF275_ (c.969C>T; p.C323=) genes; sSNV reported in the _LHX9_ (c.741T>C; p.N247=) only reported in 1000 Genomes Project and Genome Aggregation Database) and POI; rather, these findings suggest that the identified synonymous genotypes are more likely involved in the genomic variability of the Mexican population. Future studies should attempt to determine the possible impact of these synonymous variants on mRNA splicing, translation, or stability using software and tools such as ESEFinder or MMSplice. Genomic analysis identified three nsSNVs in _NR0B1_ (c.353C>T; p.A118V), _NR5A1_ (c.437G>C; p.G146A), and _NRIP1_ (c.3403C>T; p.R1135C; only reported in the 1000 Genomes Project and Genome Aggregation Database) genes from patients with POI. It is suggested that the novel coding variant p.A118V in _NR0B1_ gene identified from patients with POI and healthy subjects could only be enriching the genetic diversity; however, future functional studies should examine the role of non-coding variants in RNA biogenesis.