Novel Genomic Variants, Atypical Phenotypes and Evidence of a Digenic/Oligogenic Contribution to Disorders/Differences of Sex Development in a Large North African Cohort.

In a majority of individuals with disorders/differences of sex development (DSD) a genetic etiology is often elusive. However, new genes causing DSD are routinely reported and using the unbiased genomic approaches, such as whole exome sequencing (WES) should result in an increased diagnostic yield. Here, we performed WES on a large cohort of 125 individuals all of Algerian origin, who presented with a wide range of DSD phenotypes. The study excluded individuals with congenital adrenal hypoplasia (CAH) or chromosomal DSD. Parental consanguinity was reported in 36% of individuals. The genetic etiology was established in 49.6% (62/125) individuals of the total cohort, which includes 42.2% (35/83) of 46, XY non-syndromic DSD and 69.2% (27/39) of 46, XY syndromic DSD. No pathogenic variants were identified in the 46, XX DSD cases (0/3). Variants in the AR, HSD17B3, NR5A1 and SRD5A2 genes were the most common causes of DSD. Other variants were identified in genes associated with congenital hypogonadotropic hypogonadism (CHH), including the CHD7 and PROKR2. Previously unreported pathogenic/likely pathogenic variants (n = 30) involving 25 different genes were identified in 22.4% of the cohort. Remarkably 11.5% of the 46, XY DSD group carried variants classified as pathogenic/likely pathogenic variant in more than one gene known to cause DSD. The data indicates that variants in PLXNA3, a candidate CHH gene, is unlikely to be involved in CHH. The data also suggest that NR2F2 variants may cause 46, XY DSD.

Expanding DSD Phenotypes Associated with Variants in the DEAH-Box RNA Helicase DHX37.

Missense variants in the RNA-helicase DHX37 are associated with either 46,XY gonadal dysgenesis or 46,XY testicular regression syndrome (TRS). DHX37 is required for ribosome biogenesis, and this subgroup of XY DSD is a new human ribosomopathy. In a cohort of 140 individuals with 46,XY DSD, we identified 7 children with either 46,XY complete gonadal dysgenesis or 46,XY TRS carrying rare or novel DHX37 variants. A novel p.R390H variant within the RecA1 domain was identified in a girl with complete gonadal dysgenesis. A paternally inherited p.R487H variant, previously associated with a recessive congenital developmental syndrome, was carried by a boy with a syndromic form of 46,XY DSD. His phenotype may be explained in part by a novel homozygous loss-of-function variant in the NGLY1 gene, which causes a congenital disorder of deglycosylation. Remarkably, a homozygous p.T477H variant was identified in a boy with TRS. His fertile father had unilateral testicular regression with typical male genital development. This expands the DSD phenotypes associated with DHX37. Structural analysis of all variants predicted deleterious effects on helicase function. Similar to all other known ribosomopathies, the mechanism of pathogenesis is unknown.

Association of the CAG repeat polymorphism in mitochondrial polymerase gamma (POLG1) with male infertility: a case-control study in an Algerian population.

Polymorphisms in the have been speculated to be associated with male infertility. The main objective of our study was to CAG repeat polymorphism in POLG1 gene and male mitochondrial DNA polymerase gamma (POLG) assess the possible association of infertility in Algerian population. Genomic DNA from 89 infertile men and 84 controls was extracted using salting-out method. CAG repeat polymorphism was analyzed by the automated direct sequencing protocol. Statistical analysis was performed by Epi-info(r) (v6.0) software. A significant association with male infertility was found for CAG repeat polymorphism in heterozygous genotypes (10/≠10 vs 10/10: OR = 2.00 [0.99 - 4.05], p=0.03; "infertile vs control groups"; 10/≠10 vs 10/10: OR = 3.75[1.20-11.96], p=0.01 "oligoasthenoteratospermic group"). ALso, the results showed a significant association between the mordib allele (≠10) and male infertility (2.07 [01.07 - 04.02], p=0.01). Our results showed that POLG1 CAG repeat polymorphism might be a risk factor for male infertility in Algerian population. Investigations with larger sample sizes and representative population-based cases and matched controls are needed to validate our results.

Association of TERT, OGG1, and CHRNA5 Polymorphisms and the Predisposition to Lung Cancer in Eastern Algeria.

Lung cancer remains the most common cancer in the world. The genetic polymorphisms (rs2853669 in TERT, rs1052133 in OGG1, and rs16969968 in CHRNA5 genes) were shown to be strongly associated with the risk of lung cancer. Our study's aim is to elucidate whether these polymorphisms predispose Eastern Algerian population to non-small-cell lung cancer (NSCLC). To date, no study has considered this association in the Algerian population. This study included 211 healthy individuals and 144 NSCLC cases. Genotyping was performed using TaqMan probes and Sanger sequencing, and the data were analyzed using multivariate logistic regression adjusted for covariates. The minor allele frequencies (MAFs) of TERT rs2853669, CHRNA5 rs16969968, and OGG1 rs1052133 polymorphisms in controls were C: 20%, A: 31%, and G: 29%, respectively. Of the three polymorphisms, none shows a significant association, but stratified analysis rs16969968 showed that persons carrying the AA genotype are significantly associated with adenocarcinoma risk (pAdj = 0.03, ORAdj = 2.55). Smokers with an AA allele have a larger risk of lung cancer than smokers with GG or GA genotype (pAdj = 0.03, ORAdj = 3.91), which is not the case of nonsmokers. Our study suggests that CHRNA5 rs16969968 polymorphism is associated with a significant increase of lung adenocarcinoma risk and with a nicotinic addiction.

Angiotensin-converting enzyme insertion/deletion gene polymorphisms and the risk of glioma in an Algerian population.

INTRODUCTION: Just recently, it has been established that the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism is linked to the pathogenesis and to the evolution of human cancers. Therefore, the present study was concerned with the investigation of an eventual association between glioma and I/D polymorphism of the ACE gene. METHODS: The expression of ACE gene was detected by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis in 36 Algerian patients with glioma and 195 healthy controls. RESULTS: In glioma cases, allelic frequencies and genotypes distribution of the ACE I/D polymorphism were different from controls cases. ACE DD genotype were highly presented in glioma cases (63.9%) than controls (33.8%) and conferred 3.64-fold risk for predisposition in glioma cases (vs ID genotype, p<0.001). Recessive model (ACE II + ID genotypes vs DD) was associated with a 72% reduced risk of glioma (OR = 0.28, 95% CI: 0.13-0.60, p <0.001). Per copy D allele frequency was found higher in glioma cases (79.2%) than in controls (63.3 %), OR = 2.20, 95% CI: 1.20 - 4.03, p = 0.009. CONCLUSION: The obtained data showed that the presence of the D allele might be a risk factor for the development of glioma. Further studies considering different ethnic groups with large samples are required to confirm this finding.

γ-sarcoglycan and dystrophin mutation spectrum in an Algerian cohort.

INTRODUCTION: We report the genetic analysis of a large series of 76 Algerian patients from 65 unrelated families who presented with early onset severe muscular dystrophy and a clinical phenotype resembling limb-girdle muscular dystrophy type 2C. METHODS: To define the genetic basis of the diseases in these families, we undertook a series of analyses of the γ-sarcoglycan (SGCG) and DMD genes. RESULTS: Fifteen families were shown to carry SGCG variants. Only 2 kinds of causative mutations were identified in the population, mostly in the homozygous state: the well-known c.525delT and the previously described c.87dupT. In the DMD gene, 12 distinctive patterns of deletion were identified, mostly affecting the dystrophin central region. CONCLUSIONS: Our data suggest that a simple molecular screen consisting of 2 allele-specific polymerase chain reactions (PCRs) and a set of 3 multiplex PCRs can diagnose half of the patients who present with progressive muscular dystrophy in the developing nation of Algeria. Muscle Nerve 56: 129-135, 2017.

First study of microdeletions in the Y chromosome of Algerian infertile men with idiopathic oligo- or azoospermia.

The human Y chromosome is essential for human sex determination and spermatogenesis. The long arm contains the azoospermia factor (AZF) region. Microdeletions in this region are responsible for male infertility. The objective of this study was to determine the frequency of Y microdeletions in Algerian infertile males with azoospermia and oligoasthenoteratozoospermia syndrome (OATS) and to compare the prevalence of these abnormalities with other countries and regions worldwide. A sample of 80 Algerian infertile males with a low sperm count (1-20 × 10(6) sperms/ml) as well as 20 fertile male controls was screened for Y chromosome microdeletions. 49 men were azoospermic and 31 men had OATS. Genomic DNA was isolated from blood and polymerase chain reaction was carried out with a set of 6 AZFa, AZFb and AZFc STS markers to detect the microdeletions as recommended by the European Academy of Andrology. Among the 80 infertile men screened for microdeletion, 1 subject was found to have microdeletions in the AZFc (sY254 and sY255) region. The deletion was found in azoospermic subjects (1/49, 2%). The overall AZF deletion frequency was low (1/80, 1.3%). AZF microdeletions were observed neither in the OATS group nor in the control group. The frequency of AZF microdeletions in infertile men from Algeria was comparable to those reported in the literature. We suggest analyzing 6 STS in the first step to detect Y microdeletions in our population.

[Apolipoprotein E polymorphism and cerebral stroke]. / Polymorphisme de l'apolipoprotéine E et les accidents vasculaires cérébraux.

UNLABELLED: Our study is the type case-control realized at the Hospital of Constantine, discusses the relationship between polymorphism of apolipoprotein E and stroke. METHODS: The determination of the polymorphism of apolipoprotein E was carried out by PCR- digestion (polymerase chain reaction) using the enzyme of restriction HhaI. The study population consisted of 218 Algerian patients with stroke (divided into 63% ischemic and 37% hemorrhagic), and 509 control subjects. RESULTS: Three isoforms of apolipoprotéin E have been identified. The allelic distribution of apo E in the general population showed a predominance of the allele ɛ3 (84.3%) followed distantly by allele ɛ4 (10.7%) and ɛ2 (5%) respectively. ɛ3/ɛ4 genotype was significantly more represented among subjects with ischemic stroke (29.5%) compared with control subjects (18.8%). The odds ratio is 1.72 compared to carriers of the genotype ɛ3/ɛ3 (CI is 95% and p <0.05). CONCLUSIONS: The distribution of allelic frequencies of apolipoprotein E in the population of Constantine is similar to that of Southern Europe. Our results imply a role of the genotype of apolipoprotein E (ɛ4 allele) in the pathogenesis of stroke and are limited to the accidents of the ischemic type. The ɛ2 allele does not appear to be implied in occurred of this affection; however, large additional studies are necessary to confirm this result.

Influence of methylenetetrahydrofolate reductase C677T gene polymorphisms in Algerian infertile men with azoospermia or severe oligozoospermia.

AIMS: The C677T allele of the methylenetetrahydrofolate reductase (MTHFR) gene has been suggested to represent a risk factor for male infertility. To confirm this association, the distribution of the single-nucleotide polymorphism C677T was investigated in idiopathic infertile Algerian patients with nonobstructive azoospermia (NOA) or severe oligoasthenoteratozoospermia (OAT). A case-control study was carried out, including 74 idiopathic infertile Algerian patients with NOA (n=46) or severe OAT (n=28) and 84 fertile men as controls. Polymorphism C677T was studied by polymerase chain reaction-restriction fragment length polymorphism, and the results were statistically analyzed. RESULTS: The frequency of genotypes MTHFR 677CC, 677CT, and 677TT in idiopathic infertile men with NOA was 43.48%, 41.30%, and 15.22%; 39.29%, 50%, and 10.71% regarding the severe oligozoospermic men; and 42.86%, 45.24%, and 11.90% in the control group. CONCLUSIONS: The data suggest that the C677T MTHFR polymorphism is not a risk factor for idiopathic male subfertility in an Algerian population.