Publications by authors named "Lazhar Halouani"
Article Synopsis
- * Researchers discovered homozygous variants linked to the condition in four unrelated patients, which disrupted the localization of certain proteins essential for sperm flagellum function.
- * The study identified ZMYND12 as a new gene associated with asthenoteratozoospermia, which forms a complex with other proteins critical for sperm motility, affecting male fertility.
Article Synopsis
- The COVID-19 pandemic presents a challenge for Reproductive Medicine, which is typically considered a non-emergency activity, except for cases involving cancer-related fertility preservation.
- Leading fertility organizations like ASRM and ESHRE advised halting new patient intakes and suggested continuing only existing IVF cycles with a preference for Freeze-all strategies.
- Recent developments and new data have emerged, prompting a need to revise previously established recommendations in Tunisia, reflecting the changes in the situation.
Article Synopsis
- Structural defects in sperm flagella lead to asthenozoospermia, a common issue in infertile men, particularly seen as "short tails" (MMAF).
- Research on 167 individuals with MMAF revealed that over 30% had harmful mutations, notably in the TTC29 gene, which is crucial for sperm flagellar function.
- Further studies in model organisms confirmed that TTC29 is vital for maintaining proper sperm flagellum structure and movement, linking its mutations to male infertility.
Article Synopsis
- - Men with non-obstructive azoospermia (NOA) can potentially have viable sperm in their testes, and advanced sperm retrieval techniques like microdissection testicular sperm extraction (mTESE) are essential for improving fertility, with a sperm retrieval rate (SRR) of 60%.
- - A study conducted on 1,050 NOA patients using a modified mTESE technique with 6-fold magnifying loupes resulted in finding sperm in 61% of cases on the first testis and increased the overall SRR from 43% to 51.8%.
- - This modified mTESE technique is effective and reliable for institutions lacking an operating microscope, making it particularly beneficial for patients with
Article Synopsis
- Male infertility is a significant health issue, with multiple morphological abnormalities of the flagella (MMAF) being a severe form that causes asthenozoospermia due to irregular sperm flagella.
- Six genes linked to MMAF have been identified; however, many cases remain unexplained, indicating more undiscovered gene defects.
- Whole-exome sequencing revealed that mutations in the ARMC2 gene cause the MMAF phenotype in both humans and mice, highlighting its crucial role in sperm flagellum structure and assembly.
Article Synopsis
- Multiple morphological abnormalities of the sperm flagellum (MMAF) is a serious male infertility issue characterized by various sperm flagella defects, linked to genetic mutations affecting axonemal proteins.
- Researchers analyzed whole-exome sequencing data from 78 affected individuals and discovered a homozygous deletion in the WDR66 gene in 7 cases, indicating a new genetic contributor to MMAF.
- Further experiments, including studies on a related protein in Trypanosoma, demonstrated that this gene deletion impairs flagellar movement, thus confirming WDR66's role in male infertility related to MMAF.
Article Synopsis
- The genetic basis of oocyte meiotic deficiency (OMD), a primary infertility issue linked to immature egg production, is under-researched.
- A study using whole exome sequencing revealed that 26% of individuals with OMD carried the same harmful mutation in the PATL2 gene, which is thought to be crucial for RNA regulation.
- Experiments with knockout mice indicated that the absence of PATL2 disrupts oocyte development and maturation by affecting key gene expressions, establishing PATL2 as an important factor in mammalian fertility.
Article Synopsis
- Spermatogenesis issues affect millions of men globally, but many remain undiagnosed.
- The research identified 22 men with primary infertility linked to mutations in genes DNAH1, CFAP43, and CFAP44, confirmed through genetic sequencing.
- CRISPR/Cas9 experiments on mice demonstrated that CFAP43 and CFAP44 are crucial for producing functional sperm flagella, underscoring their importance across different species.
Patients with multiple morphological abnormalities of the sperm flagella due to DNAH1 mutations have a good prognosis following intracytoplasmic sperm injection.
Clémentine Wambergue Raoudha Zouari Selima Fourati Ben Mustapha Guillaume Martinez Françoise Devillard Lazhar Halouani
Hum Reprod
June 2016
Article Synopsis
- The study investigates whether mutations in the DNAH1 gene affect outcomes of intracytoplasmic sperm injection (ICSI) in patients with multiple morphological abnormalities of the sperm flagella (MMAF).
- Findings indicate that despite significant sperm abnormalities, MMAF patients with DNAH1 mutations exhibit low aneuploidy rates and good nuclear quality, resulting in high embryonic development success and pregnancy rates after ICSI.
- This retrospective cohort study analyzed data from 6 MMAF patients with DNAH1 mutations compared to two control groups, demonstrating that genetic factors can influence ICSI efficacy in men with sperm morphology defects.
Article Synopsis
- - In mammals, sperm-oocyte fusion triggers calcium (Ca(2+)) oscillations that are essential for oocyte activation, a crucial step for embryo development, primarily mediated by sperm-specific proteins like PLCZ1 and potentially PAWP.
- - A study of two infertile brothers revealed a harmful mutation in PLCZ1 that disrupted its function in sperm, leading to fertilization failure by causing abnormal Ca(2+) activity and early embryonic development issues.
- - The findings underscore that the absence of PLCZ1 is enough to impede oocyte activation, highlighting its critical role in fertilization, and indicate opportunities for further research on the protein’s structure and function relating to fertility.
Article Synopsis
- Researchers found that nearly all sperm from certain infertile males exhibit a rare condition with large heads and multiple tails, which is linked to a mutation in the AURKC gene.
- In a study involving two brothers with this sperm defect, a new mutation (c.436-2A>G) was discovered, causing abnormal protein production and skipping of a crucial gene segment.
- The findings emphasize the need for thorough genetic testing in similar cases, as identifying AURKC mutations indicates that any resultant sperm will be chromosomally abnormal, suggesting that intracytoplasmic sperm injection (ICSI) should not be performed.
Article Synopsis
- Many couples in Western countries rely on medical help for pregnancy, with over 2% of births resulting from assisted reproductive technologies.
- A study focused on a specific infertility condition, total globozoospermia, found that 75% of the patients had a deletion in a gene called DPY19L2, which is important for sperm development.
- This discovery allows for a molecular diagnosis in men with globozoospermia, confirming the condition and indicating a lower chance of success with in vitro fertilization.