An unusual familial Xp22.12 microduplication including EIF1AX: A novel candidate dosage-sensitive gene for premature ovarian insufficiency.

We report on the results of array-CGH and Whole exome sequencing (WES) studies carried out in a Tunisian family with 46,XX premature ovarian insufficiency (POI). This study has led to the identification of a familial Xp22.12 tandem duplication with a size of 559.4 kb, encompassing only three OMIM genes (RPS6KA3, SH3KBP1and EIF1AX), and a new heterozygous variant in SPIDR gene: NM_001080394.3:c.1845_1853delTATAATTGA (p.Ile616_Asp618del) segregating with POI. Increased mRNA expression levels were detected for SH3KBP1 and EIF1AX, while a normal transcript level for RPS6KA3 was detected in the three affected family members, explaining the absence of intellectual disability (ID). To the best of our knowledge, this is the first duplication involving the Xp22.12 region, reported in a family without ID, but rather with secondary amenorrhea (SA) and female infertility. As EIF1AX is a regulatory gene escaping X-inactivation, which has an extreme dosage sensitivity and highly expressed in the ovary, we suggest that this gene might be a candidate gene for ovarian function. Homozygous nonsense pathogenic variants of SPIDR gene have been reported in familial cases in POI. It has been suggested that chromosomal instability associated with SPIDR molecular defects supports the role of SPIDR protein in double-stranded DNA damage repair in vivo in humans and its causal role in POI. In this family, the variant (p.Ile616_Asp618del), present in a heterozygous state, is located in the domain that interacts with BLM and might disrupt the BLM binding ability of SPIDR protein. These findings strengthen the hypothesis that the additional effect of this variant could lead to POI in this family. Although the work represents the first evidence that EIF1AX duplication might be responsible for POI through its over-expression, further functional studies are needed to clarify and prove EIF1AX involvement in POI phenotype.

Development of a simple genotyping method based on indel mutations to rapidly screen SARS-CoV-2 circulating variants: Delta, Omicron BA.1 and BA.2.

The high need of rapid and flexible tools that facilitate the identification of circulating SARS-CoV-2 Variants of Concern (VOCs) remains crucial for public health system monitoring. Here, we develop allele-specific (AS)-qPCR assays targeting three recurrent indel mutations, ΔEF156-157, Ins214EPE and ΔLPP24-26, in spike (S) gene to identify the Delta VOC and the Omicron sublineages BA.1 and BA.2, respectively. After verification of the analytical specificity of each primer set, two duplex qPCR assays with melting curve analysis were performed to screen 129 COVID-19 cases confirmed between December 31, 2021 and February 01, 2022 in Sfax, Tunisia. The first duplex assay targeting ΔEF156-157 and Ins214EPE mutations successfully detected the Delta VOC in 39 cases and Omicron BA.1 in 83 cases. All the remaining cases (n = 7) were identified as Omicron BA.2, by the second duplex assay targeting Ins214EPE and ΔLPP24-26 mutations. The results of the screening method were in perfect concordance with those of S gene partial sequencing. In conclusion, our findings provide a simple and flexible screening method for more rapid and reliable monitoring of circulating VOCs. We highly recommend its implementation to guide public health policies.

Can leukocytospermia predict prostate cancer via its effects on mitochondrial DNA?

Leukocytospermia was previously reported to affect sperm quality by the production of reactive oxygen species (ROS) leading to oxidative stress (OS). In turn, OS decreases sperm functional integrity, increases sperm DNA damage and ultimately alters fertility status. To elucidate the impact of leukocytospermia on sperm nuclear DNA integrity and mitochondrial DNA (mtDNA) structure, we conducted a study including 67 samples from infertile patients with low level of leucocytes (Group 1: n = 20) and with leukocytospermia (Group 2: n = 47). In addition to standard sperm parameters' assessment, we measured the levels of inflammation biomarkers [interleukin-6 (IL-6) and interleukin-8 (IL-8)] and evaluated the oxidative status [malondialdehyde (MDA) and enzymatic and non-enzymatic antioxidants]. In addition, we evaluated the level of sperm nuclear DNA fragmentation and analysed mitochondrial DNA (mtDNA) of sperm cells by sequencing of 5 genes [cytochrome oxidase I (COXI), cytochrome oxidase II (COXII), cytochrome oxidase III (COXIII), adenosine triphosphate synthase 6 (ATPase 6) and adenosine triphosphate synthase 8 (ATPase 8)]. As expected, patients with leukocytospermia had significantly higher MDA levels (32.56 ± 24.30 nmole/ml) than patients without leukocytospermia (17.59 ± 9.60 nmole/ml) (p < .018). Also, sperm DNA fragmentation index (DFI) was significantly higher in Group 2 (33.05 ± 18.14%) as compared to Group 1 (14.19 ± 9.50%) (p < .001). The sequencing of mtDNA revealed a high number of substitutions in Group 2 (n = 102) compared to Group 1 (n = 5). These substitutions were observed mainly in COXI. Among COXI substitutions found in Group 2, twelve changes were previously described in patients with prostate cancer and six of them were shown associated with this pathology. These findings suggest that leukocytospermia may predispose to the manifestation of prostate cancer through modification of mitochondrial DNA and this may be promoted by OS.

Relationship between nuclear DNA fragmentation, mitochondrial DNA damage and standard sperm parameters in spermatozoa of infertile patients with leukocytospermia.

The association of leukocytospermia with male fertility is still under debate. Our objective was to evaluate the association of leukocytospermia with sperm parameters, mitochondrial DNA (mtDNA) variations, and seminal concentration of several oxidative stress and inflammatory cytokines in Tunisian infertile men. The studied patients were divided into two groups: patients without leukocytospermia (Group 1) and patients with leukocytospermia (Group 2). DNA fragmentation significantly increased in group 2 (31.41 %) compared to group 1 (14.68 %) ; (p < 0.001). A total of 115 nucleotide substitutions in mitochondrial DNA were depicted, among which 113 were previously identified. The number of substitutions was more elevated in group 2. Leukocytospermic group had significantly higher MDA (nmole/mL) levels than patients without leukocytospermia (34±24.43 vs 18.94±15.96 ; p=0.001), GSH (µg/mL) levels were also higher compared to the control group (126.53±22.87 vs 79.4±19.38 ; p < 0.001), SOD (U/mg of protein) levels were higher but without reaching the statistical significance (89.74±74.85 vs 67.56±37.11 ; p = 0.25) ; whereas seminal CAT (µmole H2O2/min/mg of protein) levels were lower in this group (10.66±14.32 vs 27.35±25.28 ; p = 0.012). No statistically significant differences between the two groups of patients were found in the levels of inflammatory cytokines. However, IL-8 level was positively correlated with DNA fragmentation and negatively correlated with vitality. These findings confirm the association between leukocytospermia and sperm DNA damage.