Spectrum of WAS gene mutations in Vietnamese patients with Wiskott-Aldrich syndrome.

BACKGROUND: WAS gene mutational analysis is crucial to establish a definite diagnosis of Wiskott-Aldrich syndrome (WAS). Data on the genetic background of WAS in Vietnamese patients have not been reported. METHODS: We recruited 97 male, unrelated patients with WAS and analyzed WAS gene mutation using Sanger sequencing technology. RESULTS: We identified 36 distinct hemizygous pathogenic mutations, with 17 novel variants, from 38 patients in the entire cohort (39.2%). The mutational spectrum included 14 missense, 12 indel, five nonsense, four splicing, and one non-stop mutations. Most mutations appear only once, with the exception of c.37C>T (p.R13X) and c.374G>A (p.G125E) each of which occurs twice in unrelated patients. CONCLUSION: Our data enrich the mutational spectrum of the WAS gene and are crucial for understanding the genetic background of WAS and for supporting genetic counseling.

Adult-Onset Focal Segmental Glomerulosclerosis With Steroid-Dependent Nephrotic Syndrome Caused by a Novel TBC1D8B Variant: A Case Report and Literature Review.

Focal segmental glomerulosclerosis (FSGS) is a histological lesion with a variety of potential causes, including rare variants of podocyte-related genes. Recently, it has been found that variants in the TBC1D8B gene on the X chromosome can lead to early-onset focal segmental glomerulosclerosis and steroid-resistant nephrotic syndrome by affecting endocytosis and recycling of nephrin. Here, we report a 19-year-old Chinese patient with nephrotic syndrome and normal kidney function. He had a complete remission of nephrotic syndrome after full-dose prednisone and cyclosporine treatment. Unfortunately, a relapse of nephrotic syndrome occurred during prednisone tapering. Focal segmental glomerulosclerosis was proven by a kidney biopsy, and a hemizygous pathogenic variant located in the TBC (Tre-2-Bub2-Cdc16) domain of TBC1D8B was detected by whole-exome sequencing. By comparing our case with reports of other patients with TBC1D8B variants, we suggest possible genotype-phenotype correlations. To our knowledge, this is the first report identifying a pathogenetic variant in the TBC domain of TBC1D8B in an adult-onset focal segmental glomerulosclerosis patient with steroid-dependent NS. With this report, we broaden the clinical and genetic spectrum of X-linked genetic FSGS.

Clinical and genetic features of a case with juvenile onset sandhoff disease.

BACKGROUND: Sandhoff disease (SD) is a rare neurological disease with high clinical heterogeneity. SD in juvenile form is much rarer and it is often misdiagnosed in clinics. Therein, it is necessary to provide more cases and review the literature on juvenile onset SD. CASE PRESENTATION: A 14 years-old boy with eight years of walking difficulties, and was ever misdiagnosed as spinocerebellar ataxia. We found this patient after genetic testing carried rs201580118 and a novel gross deletion in HEXB (g.74012742_74052694del). Through review the literature, we found that was the first gross deletion identified at the 3'end of HEXB, associated with juvenile onset SD from China. CONCLUSION: This case expanded our knowledge about the genotype and phenotype correlations in SD. Comprehensive genetic testing is important for the diagnosis of unexplained ataxia.

Assessing the Carcinogenicity of Vadadustat, an Oral Hypoxia-Inducible Factor Prolyl-4-Hydroxylase Inhibitor, in Rodents.

Vadadustat is an investigational oral hypoxia-inducible factor (HIF) prolyl-4-hydroxylase inhibitor to treat anemia due to chronic kidney disease (CKD). Some studies suggest that HIF activation promotes tumorigenesis by activating angiogenesis downstream of vascular endothelial growth factor, while other studies suggest that elevated HIF activity may produce an antitumor phenotype. To evaluate the potential carcinogenicity of vadadustat in mice and rats, we dosed CByB6F1/Tg.rasH2 hemizygous (transgenic) mice orally by gavage with 5 to 50 mg/kg/d of vadadustat for 6 months and dosed Sprague-Dawley rats orally by gavage with 2 to 20 mg/kg/d for approximately 85 weeks. Doses were selected based on the maximally tolerated dose established for each species in previous studies. The tumors that were identified in the studies were not considered to be treatment-related for statistical reasons or within the historical control range. There was no carcinogenic effect attributed to vadadustat in mice or rats.

Df(h22q11)/+ mouse model exhibits reduced binding levels of GABAA receptors and structural and functional dysregulation in the inhibitory and excitatory networks of hippocampus.

The 22q11.2 hemizygous deletion confers high risk for multiple neurodevelopmental disorders. Inhibitory signaling, largely regulated through GABAA receptors, is suggested to serve a multitude of brain functions that are disrupted in the 22q11.2 deletion syndrome. We investigated the putative deficit of GABAA receptors and the potential substrates contributing to the inhibitory and excitatory dysregulations in hippocampal networks of the Df(h22q11)/+ mouse model of the 22q11.2 hemizygous deletion. The Df(h22q11)/+ mice exhibited impairments in several hippocampus-related functional domains, represented by impaired spatial memory and sensory gating functions. Autoradiography using the [3H]muscimol tracer revealed a significant reduction in GABAA receptor binding in the CA1 and CA3 subregions, together with a loss of GAD67+ interneurons in CA1 of Df(h22q11)/+ mice. Furthermore, electrophysiology recordings exhibited significantly higher neuronal activity in CA3, in response to the GABAA receptor antagonist, bicuculline, as compared with wild type mice. Density and volume of dendritic spines in pyramidal neurons were reduced and Sholl analysis also showed a reduction in the complexity of basal dendritic tree in CA1 and CA3 subregions of Df(h22q11)/+ mice. Overall, our findings demonstrate that hemizygous deletion in the 22q11.2 locus leads to dysregulations in the inhibitory circuits, involving reduced binding levels of GABAA receptors, in addition to functional and structural modulations of the excitatory networks of hippocampus.

Genome Fractionation and Loss of Heterozygosity in Hybrids and Polyploids: Mechanisms, Consequences for Selection, and Link to Gene Function.

Hybridization and genome duplication have played crucial roles in the evolution of many animal and plant taxa. The subgenomes of parental species undergo considerable changes in hybrids and polyploids, which often selectively eliminate segments of one subgenome. However, the mechanisms underlying these changes are not well understood, particularly when the hybridization is linked with asexual reproduction that opens up unexpected evolutionary pathways. To elucidate this problem, we compared published cytogenetic and RNAseq data with exome sequences of asexual diploid and polyploid hybrids between three fish species; Cobitis elongatoides, C. taenia, and C. tanaitica. Clonal genomes remained generally static at chromosome-scale levels but their heterozygosity gradually deteriorated at the level of individual genes owing to allelic deletions and conversions. Interestingly, the impact of both processes varies among animals and genomic regions depending on ploidy level and the properties of affected genes. Namely, polyploids were more tolerant to deletions than diploid asexuals where conversions prevailed, and genomic restructuring events accumulated preferentially in genes characterized by high transcription levels and GC-content, strong purifying selection and specific functions like interacting with intracellular membranes. Although hybrids were phenotypically more similar to C. taenia, we found that they preferentially retained C. elongatoides alleles. This demonstrates that favored subgenome is not necessarily the transcriptionally dominant one. This study demonstrated that subgenomes in asexual hybrids and polyploids evolve under a complex interplay of selection and several molecular mechanisms whose efficiency depends on the organism's ploidy level, as well as functional properties and parental ancestry of the genomic region.

Df(h15q13)/+ Mouse Model Reveals Loss of Astrocytes and Synaptic-Related Changes of the Excitatory and Inhibitory Circuits in the Medial Prefrontal Cortex.

The 15q13.3 deletion is associated with multiple neurodevelopmental disorders including epilepsy, schizophrenia, and autism. The Df(h15q13)/+ mouse model was recently generated that recapitulates several phenotypic features of the human 15q13.3 deletion syndrome (DS). However, the biological substrates underlying these phenotypes in Df(h15q13)/+ mice have not yet been fully characterized. RNA sequencing followed by real-time quantitative PCR, western blotting, liquid chromatography-mass spectrometry, and stereological analysis were employed to dissect the molecular, structural, and neurochemical phenotypes of the medial prefrontal cortex (mPFC) circuits in Df(h15q13)/+ mouse model. Transcriptomic profiling revealed enrichment for astrocyte-specific genes among differentially expressed genes, translated by a decrease in the number of glial fibrillary acidic protein positive cells in mPFC of Df(h15q13)/+ mice compared with wild-type mice. mPFC in Df(h15q13)/+ mice also showed a deficit of the inhibitory presynaptic marker GAD65, in addition to a reduction in dendritic arborization and spine density of pyramidal neurons from layers II/III. mPFC levels of GABA and glutamate neurotransmitters were not different between genotypes. Our results suggest that the 15q13.3 deletion modulates nonneuronal circuits in mPFC and confers molecular and morphometric alterations in the inhibitory and excitatory neurocircuits, respectively. These alterations potentially contribute to the phenotypes accompanied with the 15q13.3DS.

Familial Clustering of Juvenile Psoriatic Arthritis Associated with a Hemizygous FOXP3 Mutation.

PURPOSE OF REVIEW: We describe the clinical and genetic findings in four patients from a single family who presented with refractory psoriatic arthritis and were hemizygous in the forkhead box protein 3 (FOXP3) gene (c.1222G>A). RECENT FINDINGS: We report four siblings with hemizygous mutation in the FOXP3 gene (c.1222G>A) who presented with type 1 diabetes mellitus and psoriatic arthritis poorly responsive to treatment. Our findings expand the phenotype spectrum of FOXP3 mutations. Immune dysregulation, polyendocrinopathy, and enteropathy, X-linked (IPEX) syndrome is a rare disorder caused by mutations in FOXP3 gene, which lead to early onset of constellation of autoimmune manifestations. This report highlights the influence of immune dysregulation in juvenile arthritis.

Ammonia and coma - a case report of late onset hemizygous ornithine carbamyltransferase deficiency in 68-year-old female.

BACKGROUND: Acute hyperammonemia without signs of common causes in the elderly might be challenging to identify. We report the oldest case known to date of a female patient with late onset ornithine carbamyltransferase deficiency (OTC), which was unmasked after a protein overload due to nutritional supplements. Our case illustrates how environmental factors (protein overload) in previously unknown OTC in the elderly leads to hyperammonemic encephalopathy and highlights that early treatment prevents persisting neurological deficits and should be considered in absence of common causes of hyperammonemic encephalopathy. CASE PRESENTATION: A 68-year-old woman presented with acute confusion, which progressed into a deep coma (Glasgow-Coma-Scale score 3) within a few hours. The only remarkable finding was a plasma ammonia (NH3) concentration of 697 µmmol/l (range 12-47 µmmol/). Third party history revealed that the patient disliked meat for most of her life (meat = protein, which needs to be metabolized) and had taken nutritional supplements (since supplements often have a high protein-ratio) 2 days before the symptoms started. Protein catabolism results in NH3, which is metabolized via the urea cycle. Consequently, the acute hyperammonemia in our patient was thought to be related to an inherited metabolic disorder, which only unmasked itself as a result of an overload of the corresponding metabolite (in this case protein). Since ornithine carbamyltransferase deficiency (OTC) is the most common inherited urea cycle disorder, this diagnosis became likely and was confirmed later via genetic and metabolic testing (amino acids, orotic acid, etc.). After 2 weeks of treatment (dialysis, low-protein-diet, nitrogen-lowering medication) the patient was discharged in a healthy condition without any neurological deficits. CONCLUSION: OTC is a x-chromosomal linked disorder, that usually manifests in newborn infants and children, but also rarely in adults and even rarer in the elderly (50- till 60-years-old), where it is probably underdiagnosed. In case of hyperammonemic encephalopathy - regardless of the underlying cause -, treatment should be started early to prevent persisting neurological deficits. OTC should be considered in absence of common causes of hyperammonemic encephalopathy.

A genetic linkage map for the salmon louse (Lepeophtheirus salmonis): evidence for high male:female and inter-familial recombination rate differences.

A salmon louse (Lepeophtheirus salmonis salmonis) genetic linkage map was constructed to serve as a genomic resource for future investigations into the biology of this important marine parasitic copepod species, and to provide insights into the inheritance patterns of genetic markers in this species. SNP genotyping of 8 families confirmed the presence of 15 linkage groups based upon the assignment of 93,773 markers. Progeny sample size weight adjusted map sizes in males (with the exception of SL12 and SL15) ranged in size from 96.50 cM (SL11) to 134.61 cM (SL06), and total combined map steps or bins ranged from 143 (SL09) to 203 (SL13). The SL12 male map was the smallest linkage group with a weight-averaged size of 3.05 cM with 6 recombination bins. Male:female specific recombination rate differences are 10.49:1 and represent one of the largest reported sex-specific differences for any animal species. Recombination ratio differences (M:F) ranged from 1.0 (SL12) to 29:1 (SL15). The number of markers exhibiting normal Mendelian segregation within the sex linkage group SL15 was extremely low (N = 80) in comparison to other linkage groups genotyped [range: 1459 (SL12)-10206 markers (SL05)]. Re-evaluation of Mendelian inheritance patterns of markers unassigned to any mapping parent according to hemizygous segregation patterns (models presented) identified matches for many of these markers to hemizygous patterns. The greatest proportion of these markers assigned to SL15 (N increased to 574). Inclusion of the hemizygous markers revised SL15 sex-specific recombination rate differences to 28:1. Recombination hot- and coldspots were identified across all linkage groups with all linkage groups possessing multiple peaks. Nine of 13 linkage groups evaluated possessed adjacent domains with hot-coldspot transitional zones. The most common pattern was for one end of the linkage to show elevated recombination in addition to internal regions. For SL01 and SL06, however, a terminal region with high recombination was not evident while a central domain possessing extremely high-recombination levels was present. High levels of recombination were weakly coupled to higher levels of SNP variation within domains, but this association was very strong for the central domains of SL01 and SL06. From the pooled paternal half-sib lots (several virgin females placed with 1 male), only 1 or two surviving family lots were obtained. Surviving families possessed parents where both the male and female possessed either inherently low or high recombination rates. This study provides insight into the organization of the sea louse genome, and describes large differences in recombination rate that exist among individuals of the same sex, and between the sexes. These differences in recombination rate may be coupled to the capabilities of this species to adapt to environmental and pharmaceutical treatments, given that family survivorship appears to be enhanced when parents have similar recombination levels.

The long and short of the S-locus in Turnera (Passifloraceae).

Distyly is an intriguing floral adaptation that increases pollen transfer precision and restricts inbreeding. It has been a model system in evolutionary biology since Darwin. Although the S-locus determines the long- and short-styled morphs, the genes were unknown in Turnera. We have now identified these genes. We used deletion mapping to identify, and then sequence, BAC clones and genome scaffolds to construct S/s haplotypes. We investigated candidate gene expression, hemizygosity, and used mutants, to explore gene function. The s-haplotype possessed 21 genes collinear with a region of chromosome 7 of grape. The S-haplotype possessed three additional genes and two inversions. TsSPH1 was expressed in filaments and anthers, TsYUC6 in anthers and TsBAHD in pistils. Long-homostyle mutants did not possess TsBAHD and a short-homostyle mutant did not express TsSPH1. Three hemizygous genes appear to determine S-morph characteristics in T. subulata. Hemizygosity is common to all distylous species investigated, yet the genes differ. The pistil candidate gene, TsBAHD, differs from that of Primula, but both may inactivate brassinosteroids causing short styles. TsYUC6 is involved in auxin synthesis and likely determines pollen characteristics. TsSPH1 is likely involved in filament elongation. We propose an incompatibility mechanism involving TsYUC6 and TsBAHD.

Exome sequencing of sporadic childhood-onset schizophrenia suggests the contribution of X-linked genes in males.

Childhood-onset schizophrenia (COS) is a rare and severe form of schizophrenia, defined as having an onset before the age of 13. The male COS cases have a slightly younger age of onset than female cases. They also present with a higher rate of comorbid developmental disorders. These sex differences are not explained by the frequency of chromosomal abnormalities, and the contribution of other forms of genetic variations remains unestablished. Using a whole-exome sequencing approach, we examined 12 COS trios where the unaffected parents had an affected male child. The sequencing data enabled us to test if the hemizygous variants, transmitted from the unaffected carrying mother, could mediate the phenotype (X-linked recessive inheritance model). Our results revealed that affected children have a significantly greater number of X-linked rare variants than their unaffected fathers. The variants identified in the male probands were mostly found in genes previously linked to other neuropsychiatric diseases like autism, intellectual disability, and epilepsy, including LUZP4, PCDH19, RPS6KA3, and OPHN1. The level of expression of the genes was assessed at different developmental periods in normal brain using the BrainSpan database. This approach revealed that some of them were expressed earlier in males than in females, consistent with the younger age of onset in male COS. In conclusion, this article suggests that X-linked genes might play a role in the pathophysiology of COS. Candidate genes detailed here could explain the higher level of comorbidities and the earlier age of onset observed in a subset of the male COS cases.

Genome-wide characterization and expression analysis of genetic variants in sweet orange.

Heterozyosity is an important feature of many plant genomes, and is related to heterosis. Sweet orange, a highly heterozygous species, is thought to have originated from an inter-species hybrid between pummelo and mandarin. To investigate the heterozygosity of the sweet orange genome and examine how this heterozygosity affects gene expression, we characterized the genome of Valencia orange for single nucleotide variations (SNVs), small insertions and deletions (InDels) and structural variations (SVs), and determined their functional effects on protein-coding genes and non-coding sequences. Almost half of the genes containing large-effect SNVs and InDels were expressed in a tissue-specific manner. We identified 3542 large SVs (>50 bp), including deletions, insertions and inversions. Most of the 296 genes located in large-deletion regions showed low expression levels. RNA-Seq reads and DNA sequencing reads revealed that the alleles of 1062 genes were differentially expressed. In addition, we detected approximately 42 Mb of contigs that were not found in the reference genome of a haploid sweet orange by de novo assembly of unmapped reads, and annotated 134 protein-coding genes within these contigs. We discuss how this heterozygosity affects the quality of genome assembly. This study advances our understanding of the genome architecture of sweet orange, and provides a global view of gene expression at heterozygous loci.

Hemizygous deletion of cyclin-dependent kinase inhibitor 2A/B with p16 immuno-negative and methylthioadenosine phosphorylase retention predicts poor prognosis in IDH-mutant adult glioma.

Background: Homozygous deletion of the tumor suppression genes cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) is a strong adverse prognostic factor in IDH-mutant gliomas, particularly astrocytoma. However, the impact of hemizygous deletion of CDKN2A/B is unknown. Furthermore, the influence of CDKN2A/B status in IDH-mutant and 1p/19q-codeleted oligodendroglioma remains controversial. We examined the impact of CDKN2A/B status classification, including hemizygous deletions, on the prognosis of IDH-mutant gliomas. Methods: We enrolled 101 adults with IDH-mutant glioma between December 2002 and November 2021. CDKN2A/B deletion was evaluated with multiplex ligation-dependent probe amplification (MLPA). Immunohistochemical analysis of p16/MTAP and promoter methylation analysis with methylation-specific MLPA was performed for cases with CDKN2A/B deletion. Kaplan - Meier plots and Cox proportion hazards model analyses were performed to evaluate the impact on overall (OS) and progression-free survival. Results: Of 101 cases, 12 and 4 were classified as hemizygous and homozygous deletion, respectively. Immunohistochemistry revealed p16-negative and MTAP retention in cases with hemizygous deletion, whereas homozygous deletions had p16-negative and MTAP loss. In astrocytoma, OS was shorter in the order of homozygous deletion, hemizygous deletion, and copy-neutral groups (median OS: 38.5, 59.5, and 93.1 months, respectively). Multivariate analysis revealed hazard ratios of 9.30 (P = .0191) and 2.44 (P = .0943) for homozygous and hemizygous deletions, respectively. Conclusions: CDKN2A/B hemizygous deletions exerted a negative impact on OS in astrocytoma. Immunohistochemistry of p16/MTAP can be utilized to validate hemizygous or homozygous deletions in combination with conventional molecular diagnosis.

A novel grading system combining histological grade and CDKN2A homozygous and hemizygous deletion to predict prognosis in IDH-mutant astrocytoma.

Isocitrate dehydrogenase (IDH)-mutant astrocytoma with microvascular proliferation, necrosis, CDKN2A/B homozygous deletion, or any combination of these features corresponds to World Health Organization grade 4 according to current criteria. However, the prognostic significance of CDKN2A hemizygous deletion in IDH-mutant astrocytoma is not well established. We undertook a comprehensive study that included assessments of histological and genetic approaches to prognosis for these tumors. Samples from a cohort of 114 patients with extended observation were subjected to histological review and molecular analysis. CDKN2A (9p21) deletion was detected by fluorescence in situ hybridization. Overall survival (OS) was calculated via Kaplan-Meier estimation using the log-rank test. Histological grade, Ki-67 index, and the extent of surgical resection correlated with the OS of IDH-mutant astrocytoma patients. Both CDKN2A homozygous deletion and hemizygous deletion were detectable. Patients with CDKN2A homozygous-deletion tumors had the poorest OS; those with CDKN2A hemizygous-deletion tumors had an intermediate OS (p < .001). We then established a novel grading system that combined CDKN2A homozygous and hemizygous deletions with histological grade; the combined grading system was an independent prognostic factor for IDH-mutant astrocytomas. We conclude that CDKN2A homozygous and hemizygous deletion should be combined in a grading system for IDH-mutant astrocytomas.

A novel mutation in CFAP47 causes male infertility due to multiple morphological abnormalities of the sperm flagella.

Introduction: A previous study suggested that loss of CFAP47 function is involved in multiple morphological abnormalities of the sperm flagella (MMAF) in humans and mice. However, the comprehensive role of CFAP47 in spermatogenesis is largely unknown. Methods: Whole-exome sequencing (WES) was conducted to identify pathogenic variant in two patients with MMAF. The functional effect of the identified mutations was investigated by immunofluorescence staining and western blotting. Intracytoplasmic sperm injection (ICSI) was used to assist fertilization for the patient with MMAF. Results: In this study, we identified a novel missense mutation (c.1414G>A; p.V472M) in CFAP47 in two unrelated patients with oligoasthenoteratozoospermia. Intriguingly, in addition to the MMAF phenotype very analogous to the previous report, the two patients notably presented abnormal morphology of sperm heads, the sperm mitochondrial sheath was obviously disorganized, and the sperm annulus were almost defective. Further functional experiments confirmed that the expression of CFAP47 was markedly reduced in the spermatozoa of the patients. Mechanism analysis suggested that CFAP47 might regulate the expression of CFAP65, CFAP69 and SEPTIN4 through their physical interactions and thus modulating sperm morphogenesis. Conclusion: we revealed a novel mutation in CFAP47 and further expanded the phenotype and mutation spectrum of CFAP47, as well as the potential mechanism of CFAP47 manipulating spermatogenesis, finally providing important guidance for genetic counseling and targeted treatment for CFAP47 mutation-related male infertility.

STS and PUDP Deletion Identified by Targeted Panel Sequencing with CNV Analysis in X-Linked Ichthyosis: A Case Report and Literature Review.

X-linked recessive ichthyosis (XLI) is clinically characterized by dark brown, widespread dryness with polygonal scales. We describe the identification of STS and PUDP deletions using targeted panel sequencing combined with copy-number variation (CNV) analysis in XLI. A 9-month-old infant was admitted for genetic counseling. Since the second day after birth, the infant's skin tended to be dry and polygonal scales had accumulated over the abdomen and upper extremities. The infant's maternal uncle and brother (who had also exhibited similar skin symptoms from birth) presented with polygonal scales on their trunks. CNV analysis revealed a hemizygous deletion spanning 719.3 Kb on chromosome Xp22 (chrX:7,108,996-7,828,312), which included a segment of the STS gene and exhibited a Z ratio of -2 in the proband. Multiplex ligation-dependent probe amplification (MLPA) confirmed this interstitial Xp22.31 deletion. Our report underscores the importance of implementing CNV screening techniques, including sequencing data analysis and gene dosage assays such as MLPA, to detect substantial deletions that encompass the STS gene region of Xq22 in individuals suspected of having XLI.

Novel TLR7 hemizygous variant in post-COVID-19 neurological deterioration: a case report with literature review.

The neurological complications of coronavirus disease 2019 (COVID-19) can range from simple tremors and dystonia to features of encephalopathy. Toll-like receptor 7 (TLR7) belongs to a family of innate immune receptors responsible for viral RNA detection (such as SARS-CoV-2) and immune response initiation. TLR7 loss of function variants have been previously reported as genetic risk factors for severe COVID-19 infection in young patients with no comorbidities. In this case, we report a pediatric patient who developed severe long-term neurological deterioration following his COVID-19 infection. Presenting first to the clinic with episodic dystonia and finger spasticity, the patient's condition rapidly deteriorated with a significant drop in the Glasgow Coma Scale (GCS). Despite improvement following initial treatment with rituximab and intravenous immunoglobulin, the patient's symptoms relapsed, and GCS further dropped to 3/15. Serial brain magnetic resonance imaging scans revealed diffuse parenchymal atrophy, ventricular enlargement, and spinal cord thickening. Autoimmune investigations were negative but clinical whole genome sequencing prioritized four gene variants, the most significant of which was a novel frameshift null variant of the X chromosomal TLR7 gene (c.1386_1389dup, p.[His464Ilefs*7]). This case illustrates a role for TLR7 in long-term COVID-19 complications and highlights that TLR7 deficiency in the future may be addressed as a therapeutic measure.

Deleterious variants in TAF7L cause human oligoasthenoteratozoospermia and its impairing histone to protamine exchange inducing reduced in vitro fertilization.

Introduction: Oligoasthenoteratozoospermia (OAT) is a major cause of infertility in males. Only a few pathogenic genes of OAT have been clearly identified till now. A large number of OAT-affected cases remain largely unknown. Methods: Here, Whole-exome sequencing (WES) in 725 idiopathic OAT patients was performed. Ejaculated spermatozoa by OAT patients were microinjected into mouse oocytes to estimate fertilization potential. Diff-quick staining and transmission electron microscopy were performed to evaluate sperm morphology and ultrastructure. The protein expression level and localization In vitro were detected by Western Blotting and Immunocytochemistry. Results: We identified four X-linked hemizygous deleterious variants of TAF7L-namely, c.1301_1302del;(p.V434Afs*5), c.699G>T;(p.R233S), c.508delA; (p. T170fs), c.719dupA;(p.K240fs) -in five probands. Intracytoplasmic sperm injection (ICSI) were carried out in M1, M2-1and M3 patient's wife. However only M1 patient's wife became pregnant after embryo transfer. In vitro study demonstrated significantly reduced fertilization ability in patient with TAF7L mutation. The TAF7L mutation let to abnormal sperm head and impaired histone-to protamine exchange. Variant 719dupA (p. K240fs) resulted in producing a truncated TAF7L protein and localized massively within the nucleus. In addition, TAF7L expression were not able to be detected due to variants c.1301_1302del (p. V434Afs*5) and c.508delA (p. T170fs) In vitro. Conclusion: Our findings support that TAF7L is one of pathogenic genes of OAT and deleterious mutations in TAF7L may cause impaired histone-to-protamine affected the chromatin compaction of sperm head.

Case Report: Prenatal Diagnosis of a Novel Variant c.251dupT (p.N87Kfs*6) in BCOR Resulting in Oculofaciocardiodental Syndrome Using Whole-Exome Sequencing.

Background: Oculofaciocardiodental (OFCD) syndrome is an X-linked dominant syndrome caused by BCOR variants, which manifests only in females and presumed leading to male lethality. Herein, we aim to present a prenatal diagnosis for OFCD syndrome associated with a novel hemizygous variant in BCOR gene. Case presentation: A 29-year-old pregnant woman from Quanzhou Fujian Province, China, with fetal ultrasound anomalies, was enrolled in this study. A normal 46, XY karyotype with no abnormalities was observed in the fetus detected on microarray. Furthermore, a whole-exome sequencing (WES) detection result demonstrated that a novel hemizygous variant of c.251dupT (p.N87Kfs*6) in the BCOR gene was identified in the fetus, which was a frameshift mutation and classified as a likely pathogenic variant, and may lead to OFCD syndrome according to the clinical feature of the fetus. In this case, male lethality had not occurred by the end of the second trimester, then termination of the pregnancy was conducted at a gestational age of 26 weeks. Sanger sequencing of parental samples revealed that the variant was maternally transmitted, which was consistent with the OFCD syndrome phenotypic features observed in her. Conclusions: In the study, we first present the affected male with a novel variant in BCOR that leads to the OFCD syndrome. Additionally, our study broadened the spectrum of BCOR results in the OFCD syndrome and provided the valuable references for prenatal genetic consultation.