Colorectal Cancer Archaeome: A Metagenomic Exploration, Tunisia.

Colorectal cancer (CRC) is a serious public health problem known to have a multifactorial etiology. The association between gut microbiota and CRC has been widely studied; however, the link between archaea and CRC has not been sufficiently studied. To investigate the involvement of archaea in colorectal carcinogenesis, we performed a metagenomic analysis of 68 formalin-embedded paraffin fixed tissues from tumoral (n = 33) and healthy mucosa (n = 35) collected from 35 CRC Tunisian patients. We used two DNA extraction methods: Generead DNA FFPE kit (Qiagen, Germantown, MD, USA) and Chelex. We then sequenced the samples using Illumina Miseq. Interestingly, DNA extraction exclusively using Chelex generated enough DNA for sequencing of all samples. After data filtering and processing, we reported the presence of archaeal sequences, which represented 0.33% of all the reads generated. In terms of abundance, we highlighted a depletion in methanogens and an enrichment in Halobacteria in the tumor tissues, while the correlation analysis revealed a significant association between the Halobacteria and the tumor mucosa (p < 0.05). We reported a strong correlation between Natrialba magadii, Sulfolobus acidocaldarius, and tumor tissues, and a weak correlation between Methanococcus voltae and healthy adjacent mucosa. Here, we demonstrated the feasibility of archaeome analysis from formol fixed paraffin-embedded (FFPE) tissues using simple protocols ranging from sampling to data analysis, and reported a significant association between Halobacteria and tumor tissues in Tunisian patients with CRC. The importance of our study is that it represents the first metagenomic analysis of Tunisian CRC patients' gut microbiome, which consists of sequencing DNA extracted from paired tumor-adjacent FFPE tissues collected from CRC patients. The detection of archaeal sequences in our samples confirms the feasibility of carrying out an archaeome analysis from FFPE tissues using a simple DNA extraction protocol. Our analysis revealed the enrichment of Halobacteria, especially Natrialba magadii, in tumor mucosa compared to the normal mucosa in CRC Tunisian patients. Other species were also associated with CRC, including Sulfolobus acidocaldarius and Methanococcus voltae, which is a methanogenic archaea; both species were found to be correlated with adjacent healthy tissues.

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.

Detection of a novel mutation in a Tunisian child with polycystic kidney disease.

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common monogenic disease that has an adverse impact on the patients' health and quality of life. ADPKD is usually known as "adult-type disease," but rare cases have been reported in pediatric patients. We present here a 2-year-old Tunisian girl with renal cyst formation and her mother with adult onset ADPKD. Disease-causing mutation has been searched in PKD1 and PKD2 using Long-Range and PCR followed by sequencing. Molecular sequencing displayed us to identify a novel likely pathogenic mutation (c.696 T > G; p.C232W, exon 5) in PKD1. The identified PKD1 mutation is inherited and unreported variant, which can alter the formation of intramolecular disulfide bonds essential for polycystin-1 function. We report here the first mutational study in pediatric patient with ADPKD in Tunisia.

First report of an unusual novel double mutation affecting the transcription repression domain of MeCP2 and causing a severe phenotype of Rett syndrome: Molecular analyses and computational investigation.

Rett syndrome is an X-linked neurodevelopmental disorder that develops a profound intellectual and motor disability and affects 1 from 10 000 to 15 000 live female births. This disease is characterized by a period of apparently normal development until 6-18 months of age when motor and communication abilities regress which is caused by mutations occurred in the X-linked MECP2 gene, encoding the methyl-CpG binding protein 2. This research study reports a molecular analysis via an exhaustive gene sequencing which reveals an unusual novel double mutation (c.695 G > T; c.880C > T) located in a highly conserved region in MECP2 gene affecting the transcription repression domain (TRD) of MeCP2 protein and leading for the first time to a severe phenotype of Rett syndrome. Moreover, a computational investigation of MECP2 mutations demonstrates that the novel mutation c.695 G > T is highly deleterious which affects the MeCP2 protein showing also an adverse impact on MECP2 gene expression and resulting in an affected folding and decreased stability of MECP2 structures. Thus, the altered TRD domain engenders a disrupted process of MECP2 functions. Therefore, this is the first study which highlights a novel double mutation among the transcription repression domain (TRD) of MeCP2 protein in Rett patient with a severe clinical phenotype in North Africa region.

Identification of a novel m.9588G > a missense mutation in the mitochondrial COIII gene in asthenozoospermic Tunisian infertile men.

PURPOSE: Infertility affects 10-15 % of the population, of which, approximately 40 % is due to male etiology consisting primarily of low sperm count (oligozoospermia) and/or abnormal sperm motility (asthenozoospermia). It has been demonstrated that mtDNA base substitutions can greatly influence semen quality. METHODS: In the present study we performed a systematic sequence analysis of the mitochondrial cytochrome oxidase III (COIII) gene in 31 asthenozoospermic infertile men in comparaison to normozoospermic infertile men (n=33) and fertile men (n=150) from Tunisian population. RESULTS: A novel m.9588G>A mutation was found in the mtDNA sperm's in all asthenozoospermic patients and was absent in the normozoospermic and in fertile men. The m.9588G>A mutation substitutes a highly conserved Glutamate at position 128 to Lysine. In addition, PolyPhen-2 analysis predicted that this variant is "probably damaging".

Genetic insights into fetal kidney development: Variants in HNF1A and PKHD1 genes.

The orchestration of fetal kidney development involves the precise control of numerous genes, including HNF1A, HNF1B and PKHD1. Understanding the genetic factors influencing fetal kidney development is essential for unraveling the complexities of renal disorders. This study aimed to search for disease-causing variants in HNF1A, HNF1B, PKHD1 genes, among fetus and babies or via parental samples, using sanger sequencing, NGS technologie and MLPA. The study revealed an absence of gene deletions and disease-causing variants in the HNF1B gene. However, five previously SNPs in the HNF1A gene were identified in four patients (patients 1, 2, 3, and 4). These include c.51C > G (Exon1, p. Leu17=), c.79A > C (Exon1, p. Ile27Leu), c.1375C > T (Exon7, p. Leu459=), c.1460G > A (Exon7, p. Ser487Asn), and c.1501 + 7G > A (Intron7). Additionally, in addition to previously SNPs identified, a de novo heterozygous missense mutation (p.E508K) was detected in patient 4. Furthermore, a heterozygous mutation in exon 16 (p. Arg494*; c.1480C > T) was identified in both parents of patient 5, allowing predictions of fetal homozygosity. Bioinformatic analyses predicted the effects of the c.1522G > A mutation (p.E508K) on splicing processes, pre-mRNA structures, and protein instability and conformation. Similarly, the c.1480C > T mutation (p. Arg494*) was predicted to introduce a premature codon stop, leads to the production of a shorter protein with altered or impaired function. Identification of variants in the HNF1A and in PKHD1 genes provides valuable insights into the genetic landscape of renal abnormalities in affected patients. These findings underscore the heterogeneity of genetic variants contributing to renal disorders and emphasize the importance of genetic screening.

Pericentric inversion of chromosom 12 [Inv (12) (p12q12)] associated with idiopathic azoospermia in one infertile Tunisian man.

Chromosome aberrations are found in 2-7% of couples with fertility problems and pericentric inversions are structural chromosomal abnormalities, potentially associated with infertility or multiple miscarriages. In this study, we report the first case of pericentric inversion of chromosome 12 associated with non-obstructive azoospermia. A karyogram revealed pericentric inversion of chromosome 12 with breakpoints at 12p12 and 12q12. Testicular histopathology confirmed the Sertoli cell-only syndrome.

A novel m.6307A>G mutation in the mitochondrial COXI gene in asthenozoospermic infertile men.

Infertility affects 10-15% of the population, of which approximately 40% is due to male etiology and consists primarily of low sperm count (oligozoospermia) and/or abnormal sperm motility (asthenozoospermia). Recently, it has been demonstrated that mtDNA substitutions can influence semen quality. In this study, we performed a sequence analysis of the mitochondrial cytochrome oxidase I (COXI) gene in 31 infertile men suffering from asthenozoospermia in comparison to 33 normozoospermic infertile men and 100 fertile men from the Tunisian population. A novel m.6307A>G mutation was found in sperm mitochondrial DNA (mtDNA). This mutation was found in six asthenozoospermic patients, and was absent in normozoospermic and fertile men. We also detected 21 known substitutions previously reported in the Human Mitochondrial Database. The m.6307A>G mutation substitutes a highly conserved asparagine at position 135 to serine. In addition, PolyPhen-2 analysis predicted that this variant is "probably damaging.

Mitochondrial DNA mutations and polymorphisms in asthenospermic infertile men.

In this study we performed a systematic sequence analysis of 6 mitochondrial genes (cytochrome oxidase I, cytochrome oxidase II, cytochrome oxidase III, adenosine triphosphate synthase6, ATP synthase8, and cytochrome b] in 66 infertile men suffering from asthenospermia (n=34) in comparison to normospermic infertile men (n=32) and fertile men (n=100) from Tunisian population. A total of 72 nucleotide substitutions in blood cells mitochondrial DNA were found; 63 of them were previously identified and reported in the human mitochondrial DNA database ( www.mitomap.org ) and 9 were novel. We also detected in 3 asthenospermic patients a novel heteroplasmic missense mitochondrial mutation (m.9387 G>A) in COXIII gene (8.8%) that was not found in any of normospermic infertile and fertile men. This mutation substituting the valine at position 61 to methionine in a conserved amino acid in the transmembrane functional domain of the polypeptide, induces a reduction of the hydropathy index (from +1.225 to +1.100) and a decrease of the protein 3D structures number (from 39 to 32) as shown by PolyPhen bioinformatic program.

Y-chromosome haplogroups and Azoospermia Factor (AZF) analysis in Tunisian infertile male.

The aim of the present study was to clarify the implication of Y chromosome genetic variations and haplogroups in Tunisian infertile men. A total of 27 Y-chromosomal binary markers partial microdeletions (gr/gr, b1/b3 and b2/b3) and copy number variation of DAZ and CDY genes in the AZFc region were analysed in 131 Tunisian infertile men with spermatogenic failure and severe reduced sperm concentrations and in 85 normospermic men as controls. Eleven different haplogroups in the overall population study (E3b2; J1J*, E1, E3b*, F, G, K, P/Q, R*, R1* and R1a1) were found. Interestingly, the J1J* haplogroup was significantly more frequent in azoo/oligospermic patients than in normospermic men (35.1% and 22.3%, respectively (p value = 0.04)). Results showed also that patients without DAZ/CDY1 copies loss and without partial microdeletions belonged to the R1 haplogroup. The relative high frequencies of two haplogroups, E3b2 (35.1%) and J (30%) was confirmed in Tunisia. We reported in the present study and for the first time, that J1J* haplogroup may confer a risk factor for infertility in the Tunisian population and we suggested that R1 haplogroup may ensure certain stability to Y-chromosome in Tunisian men.

The Archaeome's Role in Colorectal Cancer: Unveiling the DPANN Group and Investigating Archaeal Functional Signatures.

BACKGROUND AND AIMS: Gut microbial imbalances are linked to colorectal cancer (CRC), but archaea's role remains underexplored. Here, using previously published metagenomic data from different populations including Austria, Germany, Italy, Japan, China, and India, we performed bioinformatic and statistical analysis to identify archaeal taxonomic and functional signatures related to CRC. METHODS: We analyzed published fecal metagenomic data from 390 subjects, comparing the archaeomes of CRC and healthy individuals. We conducted a biostatistical analysis to investigate the relationship between Candidatus Mancarchaeum acidiphilum (DPANN superphylum) and other archaeal species associated with CRC. Using the Prokka tool, we annotated the data focusing on archaeal genes, subsequently linking them to CRC and mapping them against UniprotKB and GO databases for specific archaeal gene functions. RESULTS: Our analysis identified enrichment of methanogenic archaea in healthy subjects, with an exception for Methanobrevibacter smithii, which correlated with CRC. Notably, CRC showed a strong association with archaeal species, particularly Natrinema sp. J7-2, Ferroglobus placidus, and Candidatus Mancarchaeum acidiphilum. Furthermore, the DPANN archaeon exhibited a significant correlation with other CRC-associated archaea (p < 0.001). Functionally, we found a marked association between MvhB-type polyferredoxin and colorectal cancer. We also highlighted the association of archaeal proteins involved in the biosynthesis of leucine and the galactose metabolism process with the healthy phenotype. CONCLUSIONS: The archaeomes of CRC patients show identifiable alterations, including a decline in methanogens and an increase in Halobacteria species. MvhB-type polyferredoxin, linked with CRC and species like Candidatus Mancarchaeum acidiphilum, Natrinema sp. J7-2, and Ferroglobus placidus emerge as potential archaeal biomarkers. Archaeal proteins may also offer gut protection, underscoring archaea's role in CRC dynamics.

Chromosomal defects in infertile men with poor semen quality.

PURPOSE: To assess the incidence and the type of chromosomal aberrations in males with infertility we reviewed cytogenetic results in 76 Tunisian infertile men (54 nonobstructive azoospermia and 22 oligo-asthenospermia). METHODS: Karyotyping was performed on peripheral blood lymphocytes according to the standard methods. Molecular diagnosis of classical and partial Y-chromosomal microdeletions was performed by amplifying Y-specific STSs markers. RESULTS: Various numerical and structural chromosome abnormalities were identified in 15 patients (19.48%). The occurrence of chromosomal abnormality in the azoospermics and severe oligo-asthnospermic was 21.7% and 13.5%, respectively. The most common was Klinefelter syndrome, accounting for 10 of the 15 cytogenetic defects. The total frequency of Y chromosomal microdeletions was 17.1%, with respective frequencies in azoospermic and severe oligospermic groups, 11.1% and 31.8%. The most frequent of Y chromosomal deletions were the partial ones (11.1% in azoospermic and 27.2% in oligospermic). CONCLUSION: The occurrence of chromosomal abnormalities among infertile males strongly suggests the need for routine genetic testing and counseling prior to the employment of assisted reproduction techniques.

Autosomal dominant polycystic kidney disease (ADPKD) in Tunisia: From molecular genetics to the development of prognostic tools.

A high prevalence of genetic kidney disease in Tunisia has been detected, and their study provides very important clinical and genetic information. Autosomal dominant polycystic kidney disease (ADPKD) is one of the main causes of morbidity and mortality associated with the kidneys in Tunisia. We present here clinical and genetic characteristics of a cohort of Tunisian patients with ADPKD. Nineteen Tunisian patients with ADPKD, among 4 familial cases and 11 sporadic cases, and 50 Healthy individuals were included in this cohort. Genetic studies of PKD1/2 were carried on using Sanger sequencing and MLPA. In our study, the mean age at diagnosis was 47 ± 18 years. In addition, 84.21% of cases present a family history of ADPKD. Overall, 57.89% of the affected individuals had HTA and 26.31% patients had hematuria. 15.78 % of the patient has extra-renal cysts i.e. one patient with splenic cysts and two patients had liver cysts. 57.89 % of patients were diagnosed with various extra-renal clinical presentations i.e. myopia, hernia, deafness, intracranial aneurysm, respiratory distress, hyperthyroidism, urinary tract infection and lower back pains. The PKD1 genotype showed earlier onset of ESRD compared to PKD2 genotype (43 vs. 55 years old). Six mutations have been detected in PKD1 gene. Among them, three were novels e.g. c.688 T>G, p.C230G and c.690C>G, p.C230W among exon 5 and c.8522A>G, p.N2841S among exon 23. In addition, thirteen single nucleotides polymorphisms have been reported in PKD1 gene. Among them, eleven previously reported in heterozygous state and two novel single nucleotides polymorphisms in heterozygous and homozygous state and predicted to be probable polymorphisms by computational tools: c.496C>T, p.L166= among the exon 4, and c.10165G>C and p.E3389Gln among the exon 31. Only three single nucleotides polymorphisms previously reported in ADPKD database have been identified in PKD2 gene. The description and analysis of our cohort can help in rapid and reliable diagnosis for early management of patients in Tunisia. Indeed, predictive genetic testing can facilitate donor evaluation and increase living related kidney transplantation.

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.

Dimethoate-induced oxidative stress in human erythrocytes and the protective effect of vitamins C and E in vitro.

Organophosphorus insecticides may induce oxidative stress leading to the generation of free radicals and alteration in the antioxidant system. The aim of this study was to examine the potency of Dimethoate (Dim) to induce oxidative stress response in human erythrocyte in vitro and the role of Vitamins C (Vit C) and E (Vit E) in alleviating the cytotoxic effects. Erythrocytes were divided into three groups. The first group, erythrocytes were incubated for 4 h at 37 °C with different concentrations (0, 20, 40, 60, 80, and 100 mM) of Dim. The second and third groups were preincubated with Vit C or Vit E, respectively, for 30 min and followed by Dim incubation for 4 h at 37 °C. Following in vitro exposure, Dim caused a significant increase in malondialdehyde (MDA) levels, superoxide dismutase (SOD), and catalase (CAT) in erythrocytes at different concentrations. Vit E or Vit C pretreated erythrocytes showed a significant protection against the cytotoxic effects inducted by Dim on the studied parameters. In conclusion, antioxidant Vit E and C could protect against Dim-induced oxidative stress by decreasing lipid peroxidation and hyperactivity of SOD and CAT in human erythrocytes.

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.

Genetic association between AZF region polymorphism and Klinefelter syndrome.

Because of conflicting results about the association between azoospermic patients with Klinefelter syndrome (KFS) and azoospermia factor (AZF) polymorphism, and because nothing is known about the association of KFS with partial AZFc deletions, an association study was performed in Tunisian KFS patients. A total of 29 azoospermic patients and 13 fertile men were enrolled in this study. The classical microdeletions were found in six out of nine KFS patients (67%). Gr/Gr deletions and b2/b3 deletions are partial AZFc deletions. One KFS patient without classical microdeletions had a gr/gr deletion. This deletion (gr/gr) was observed in four out of 18 azoospermic patients without chromosomal abnormalities. In addition, two b2/b3 and one AZFc deletion were identified in this group. All KFS patients had elevated plasma FSH and LH concentrations, but normal plasma testosterone concentration. The testis biopsy of three samples with Y microdeletions revealed Sertoli cell-only syndrome. No Y microdeletions or partial AZFc deletions were found in the fertile group. It is concluded that in the patient population KFS patients may harbour Y microdeletions, and screening for these should be part of the diagnostic work-up, particularly in those considering assisted reproductive techniques. However, partial AZFc deletions might not play a role in predisposing genetic background for the phenotype of azoospermic KFS subjects.

Lipid peroxidation and antioxidant enzyme activities in infertile men: correlation with semen parameter.

The aim of this study was to investigate the oxidative stress status and antioxidant enzyme activities in infertile men's semen and to determine their relationship with spermatozoa characteristics. Four groups of infertile men, normozoospermic (n=9), azoospermic (n=13), oligoasthenozoospermic (n=38), and asthenozoospermic (n=42), were tested for malonaldialdehyde (MDA) concentration and catalase (CAT) and superoxide dismutase (SOD) activities in semen using spectrophotometric methods. We found that MDA levels in semen and SOD activity in seminal plasma (SP) were significantly higher in oligoasthenozoospermic and asthenozoospermic groups compared with normozoospermic group. In contrast, the mean values of CAT activity were not significantly different in all groups. We found positive correlations between semen MDA concentration and SOD activity (P<0.01). MDA levels in sperm pellet and in SP were also positively correlated with mobility grade b (P<0.01), acrosome anomalies (P<0.01), and residual cytoplasmic droplets (P<0.05). In contrast, SOD activity in SP was negatively correlated with sperm concentration and normal morphology (P<0.05). Similarly, CAT activity in SP was negatively correlated with sperm and leukocyte concentrations (P<0.05). In conclusion, our results suggest that the evaluation of oxidative status and antioxidant defenses may be taken as an important tool for diagnosis and treatment of male infertility.

A novel disease-causing mutation in the Renin gene in a Tunisian family with autosomal dominant tubulointerstitial kidney disease.

Autosomal dominant tubulointerstitial kidney disease (ADTKD) is a rare group of disease that affect the tubules of the kidney. There are 4 known subtypes of ADTKD classified based on causative genes and clinical features. In our study, we aimed to identify the causative subtypes of ADTKD in a Tunisian ADTKD family (3 affected members), in whom standard nephrological diagnosis did not provide clear subtype of ADTKD, until genetic testing was performed. Sanger sequencing was performed for UMOD, HNF1ß and REN genes. Mutational analysis allowed us to detect a heterozygous mutation in the REN gene: c.1172C > G, (p.T391R) in exon 10. In silico analyses predicted that the novel likely pathogenic mutation affect protein stability and 3D structure. Our study highlights the importance of establishing a genetic diagnosis to identify the subtype of ADTKD for better patient care. To the best of our knowledge, we report here a first Tunisian ADTKD-REN family.

A novel C-terminal truncated mutation in hCDKL5 protein causing a severe West syndrome: Comparison with previous truncated mutations and genotype/phenotype correlation.

INTRODUCTION: West Syndrome is a severe epileptic encephalopathy characterized by epileptic spasms, hypsarrhythmia, and regression of psychomotor acquisitions beginning in the first year of life. ARX and CDKL5 genes were identified as linked to the most frequent genetic causes of West Syndrome. METHODS: The present study reports the clinical, molecular and bioinformatic investigation of the patient with severe West syndrome. RESULTS: Molecular analysis of the two candidate genes, i.e. ARX and CDKL5 showed the presence of a novel insertion c.2788insG in exon 19 of CDKL5 gene. This mutation causes changes in cis regulation elements of exon 19 splicing and in secondary pre-mRNA structure leading probably to inclusion of alternative exon 19 in hCDKL5_5 isoform for which foetal brain expression was recently confirmed. This insertion led also to a frameshift mutation and generated a premature stop codon (p.E930Gfs9X) in the C- terminal domain and causing the lack of a part of the signal recognized by proteasome as well as the lack of peptidase I serine active site. Moreover, we review previously described, truncated mutations occurring in different regions of the C- terminal domain, and we compared the subcellular mutated protein localization and their resulting patients' phenotypes. CONCLUSIONS: The impairment of alternative splicing of exon 19 and the lack of a part of the proteasome signal due to c.2788insG mutation could disrupt the dynamic regulation of isoform levels especially hCDKL5_5 and hCDKL5_1 during pre and postnatal neurodevelopment and then could cause pathogenic phenotype. Signal peptidase I serine active site seems to modulate hCDKL5_5 movements between nucleus and cytoplasm. We noticed that the resulting phenotypes from truncated mutations among the C-terminal domain of hCDKL5 are almost similar and are always severe.