Deletion of ACTRT1 is associated with male infertility as sperm acrosomal ultrastructural defects and fertilization failure in human.

STUDY QUESTION: Could actin-related protein T1 (ACTRT1) deficiency be a potential pathogenic factor of human male infertility? SUMMARY ANSWER: A 110-kb microdeletion of the X chromosome, only including the ACTRT1 gene, was identified as responsible for infertility in two Chinese males with sperm showing acrosomal ultrastructural defects and fertilization failure. WHAT IS KNOWN ALREADY: The actin-related proteins (e.g. ACTRT1, ACTRT2, ACTL7A, and ACTL9) interact with each other to form a multimeric complex in the subacrosomal region of spermatids, which is crucial for the acrosome-nucleus junction. Actrt1-knockout (KO) mice are severely subfertile owing to malformed sperm heads with detached acrosomes and partial fertilization failure. There are currently no reports on the association between ACTRT1 deletion and male infertility in humans. STUDY DESIGN, SIZE, DURATION: We recruited a cohort of 120 infertile males with sperm head deformations at a large tertiary hospital from August 2019 to August 2023. Genomic DNA extracted from the affected individuals underwent whole exome sequencing (WES), and in silico analyses were performed to identify genetic variants. Morphological analysis, functional assays, and ART were performed in 2022 and 2023. PARTICIPANTS/MATERIALS, SETTING, METHODS: The ACTRT1 deficiency was identified by WES and confirmed by whole genome sequencing, PCR, and quantitative PCR. Genomic DNA of all family members was collected to define the hereditary mode. Papanicolaou staining and electronic microscopy were performed to reveal sperm morphological changes. Western blotting and immunostaining were performed to explore the pathological mechanism of ACTRT1 deficiency. ICSI combined with artificial oocyte activation (AOA) was applied for one proband. MAIN RESULTS AND THE ROLE OF CHANCE: We identified a whole-gene deletion variant of ACTRT1 in two infertile males, which was inherited from their mothers, respectively. The probands exhibited sperm head deformations owing to acrosomal detachment, which is consistent with our previous observations on Actrt1-KO mice. Decreased expression and ectopic distribution of ACTL7A and phospholipase C zeta were observed in sperm samples from the probands. ICSI combined with AOA effectively solved the fertilization problem in Actrt1-KO mice and in one of the two probands. LIMITATIONS, REASONS FOR CAUTION: Additional cases are needed to further confirm the genetic contribution of ACTRT1 variants to male infertility. WIDER IMPLICATIONS OF THE FINDINGS: Our results reveal a gene-disease relation between the ACTRT1 deletion described here and human male infertility owing to acrosomal detachment and fertilization failure. This report also describes a good reproductive outcome of ART with ICSI-AOA for a proband. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Chongqing medical scientific research project (Joint project of Chongqing Health Commission and Science and Technology Bureau, 2023MSXM008 and 2023MSXM054). There are no competing interests to declare. TRIAL REGISTRATION NUMBER: N/A.

Novel biallelic variants in DNAH1 cause multiple morphological abnormalities of sperm flagella with favorable outcomes of fertility after ICSI in Han Chinese males.

BACKGROUND: Multiple morphological abnormalities of sperm flagella is an idiopathic asthenoteratozoospermia characterized by absent, short, coiled, angulation, and irregular-caliber flagella. Genetic variants of DNAH1 gene have been identified as a causative factor of multiple morphological abnormalities of sperm flagella and intracytoplasmic sperm injection is an available strategy for infertile males with dynein axonemal heavy chain 1 defects to conceive. OBJECTIVES: To identify novel variants and candidate mutant hotspots of DNAH1 gene related to multiple morphological abnormalities of sperm flagella and male infertility in humans. MATERIALS AND METHODS: The DNAH1 variants were identified by whole exome sequencing and confirmed with Sanger sequencing. Papanicolaou staining, scanning and transmission electron microscopy, and immunostaining were performed to investigate the morphological and ultrastructural characteristics of spermatozoa. Intracytoplasmic sperm injection was applied for the assisted reproductive therapy of males harboring biallelic DNAH1 variants. RESULTS: We identified 18 different DNAH1 variants in 11 unrelated families, including nine missense variants (p.A2564T, p.T3657R, p.G1862R, p.L2296P, p.T4041I, p.L611P, p.A913D, p.R1932Q, p.R2356W) and nine loss-of-function variants (c.2301-1G>T, p.Q1518*, p.R1702*, p.D2845Mfs*2, p.P3909Rfs*33, p.Q4040Dfs*33, p.Q4058*, p.E4060Pfs*61, p.V4071Cfs*54). A total of 66.7% (12/18) of the identified variants were novel. Morphological analysis based on Papanicolaou staining and scanning electron microscopy demonstrated the typical multiple morphological abnormalities of sperm flagella characteristics of dynein axonemal heavy chain 1-deficient spermatozoa. Immunostaining further revealed the absence of inner dynein arms but not outer dynein arms, which induced a general ultrastructural disorganization, such as the loss of central pair and mis-localization of the microtubule doublets and outer dense fibers. To date, seven affected couples have accepted the intracytoplasmic sperm injection treatment, and three of them have given birth to five healthy babies. DISCUSSION AND CONCLUSION: These findings further expand the variant spectrum of DNAH1 gene related to multiple morphological abnormalities of sperm flagella and male infertility in humans, thus providing new information for the molecular diagnosis of asthenoteratozoospermia. The favorable fertility outcomes of intracytoplasmic sperm injection will facilitate the genetic counseling and clinical treatment of infertile males with multiple morphological abnormalities of sperm flagella in the future.

Patients with MMAF induced by novel biallelic CFAP43 mutations have good fertility outcomes after intracytoplasmic sperm injection.

As a specific type of asthenoteratozoospermia, multiple morphological abnormalities of the sperm flagella (MMAF) is characterized by composite abnormalities, including absent, short, coiled, angulation, and irregular-caliber flagella. Mutations in cilia- and flagella-associated protein 43 ( CFAP43 ) are one of the main causative factors of MMAF established to date. To identify whether there are other CFAP43 mutations related to MMAF and to determine the clinical outcomes of assisted reproductive technology for patients with MMAF harboring different mutations, we recruited and screened 30 MMAF-affected Chinese men using a 22-gene next-generation sequencing panel. After systematic analysis, seven mutations in CFAP43 , including five novel mutations and two previously reported mutations, were identified from four families and related to MMAF in an autosomal recessive pattern. Papanicolaou staining, immunofluorescence, and electronic microscopy further clarified the semen characteristics and abnormal sperm morphologies, including disorganized axonemal and peri-axonemal structures, of the CFAP43 -deficient men. The female partners of two patients were pregnant after undergoing assisted reproductive technology through intracytoplasmic sperm injection, and one of them successfully gave birth to a healthy boy. This study significantly expands the mutant spectrum of CFAP43 , and together with the available information regarding male infertility and MMAF, provides new information for the genetic diagnosis and counseling of MMAF in the future.

Circadian Rhythm Sleep Disorders: Genetics, Mechanisms, and Adverse Effects on Health.

Nearly all living organisms, from cyanobacteria to humans, have an internal circadian oscillation with a periodicity of approximately 24 h. In mammals, circadian rhythms regulate diverse physiological processes including the body temperature, energy metabolism, immunity, hormone secretion, and daily sleep-wake cycle. Sleep is tightly regulated by circadian rhythms, whereas a misalignment between the circadian rhythms and external environment may lead to circadian rhythm sleep disorders (CRSD). CRSD includes four main kinds of disorders: the advanced sleep-wake phase disorder (ASPD), the delayed sleep-wake phase disorder (DSPD), the irregular sleep-wake rhythm disorder and the non-24-h sleep-wake rhythm disorder. Recent studies have begun to shed light on the genetic basis of CRSD. Deciphering the genetic codes for ASPD and DSPD has so far been more successful than the other CRSDs, which allow for the development of animal models and understanding of the pathological mechanisms for these disorders. And studies from humans or animal models implicate CRSDs are associated with adverse health consequences, such as cancer and mental disorders. In this review, we will summarize the recent advances in the genetics, underlying mechanisms and the adverse effects on health of ASPD and DSPD.

[Comparison of sensitivity of audiological tests to identify otitis media with effusion in newborn infants].

OBJECTIVE: To investigate the sensitive factors which were used in routine audiological tests to find out otitis media with effusion (OME) in newborn infants. METHODS: Subjects of this study were 48 infants, including 31 males and 17 females, who failed in the universal newborn hearing screening. The age ranged from 1.5 to 12 months with the average age of 4.3 months. All subjects accepted temporal bone CT and routine audiological assessments, including air-conduction and bone-conduction auditory brainstem response (ABR), 40 Hz-auditory event related potential (40 Hz-AERP), distortion-product otoacoustic emission (DPOAE), acoustic reflex, tympanometries using 226 Hz and 1000 Hz probe tone. Nine factors were statistically analyzed using Kappa test, Univariate chi(2) test and multivariate condition Logistic stepwise regression analysis, which included the results of acoustic immittance, the air-conduction and bone-conduction ABR thresholds, the difference between air-conduction and bone-conduction ABR thresholds, the latency of ABR wave I, duration between ABR wave I and V, 40 Hz-AERP thresholds, amplitudes and thresholds of DPOAE, and acoustic reflex thresholds (ART). RESULTS: Seventy-seven ears were diagnosed with OME, and 19 ears were normal. CT scan of temporal bone was set as a comparative standard. Kappa test indicated that the results of tympanometry with 1000 Hz probe tone (Kappa = 0.745, P < 0.001), the air-conduction ABR threshold (Kappa = 0.453, P < 0.001), the latency of ABR wave I (Kappa = 0.430, P < 0.001), the threshold of 40 Hz-AERP (Kappa = 0.582, P < 0.001), and DPOAE (Kappa = 0.495, P < 0.001) had agreement with the results of temporal bone CT on evaluating the function of middle ear. Univariate analysis indicated that sensitive factors of middle ear function in newborn infants were tympanometry with 1000 Hz probe tone (P < 0.001), ART (P < 0.001), the air-conduction ABR threshold (P < 0.001), the difference between air-conduction and bone-conduction ABR thresholds (P < 0.001), the latency of ABR wave I (P < 0.001), the threshold of 40 Hz-AERP (P < 0.001) and DPOAE (P < 0.001). And multivariate conditional Logistic stepwise regression model showed that tympanometry with 1000 Hz probe tone (P < 0.001) and 40 Hz-AERP threshold (P = 0.004) can be substituted into Logistic stepwise regression equation. CONCLUSIONS: Tympanometry with 1000 Hz probe tone and are sensitive factors to find out OME in newborn infants. The air conduction ABR threshold, ABR wave I latency, 40 Hz-AERP threshold and DPOAE could reflect the middle ear function of newborn infants effectively.