Monogenic Disorders Research Articles

High-throughput screening for small-molecule stabilizers of misfolded glucocerebrosidase in Gaucher disease and Parkinson’s disease

Glucocerebrosidase (GCase) is implicated in both a rare, monogenic disorder (Gaucher disease, GD) and a common, multifactorial condition (Parkinson's disease, PD); hence, it is an urgent therapeutic target. To identify correctors of severe protein misfolding and trafficking obstruction manifested by the pathogenic L444P-variant of GCase, we developed a suite of quantitative, high-throughput, cell-based assays. First, we labeled GCase with a small proluminescent HiBiT peptide reporter tag, enabling quantitation of protein stabilization in cells while faithfully maintaining target biology. TALEN-based gene editing allowed for stable integration of a single HiBiT-GBA1 transgene into an intragenic safe-harbor locus in GBA1-knockout H4 (neuroglioma) cells. This GD cell model was amenable to lead discovery via titration-based quantitative high-throughput screening and lead optimization via structure-activity relationships. A primary screen of 10,779 compounds from the NCATS bioactive collections identified 140 stabilizers of HiBiT-GCase-L444P, including both pharmacological chaperones (ambroxol and noninhibitory chaperone NCGC326) and proteostasis regulators (panobinostat, trans-ISRIB, and pladienolide B). Two complementary high-content imaging-based assays were deployed to triage hits: The fluorescence-quenched substrate LysoFix-GBA captured functional lysosomal GCase activity, while an immunofluorescence assay featuring antibody hGCase-1/23 directly visualized GCase lysosomal translocation. NCGC326 was active in both secondary assays and completely reversed pathological glucosylsphingosine accumulation. Finally, we tested the concept of combination therapy by demonstrating synergistic actions of NCGC326 with proteostasis regulators in enhancing GCase-L444P levels. Looking forward, these physiologically relevant assays can facilitate the identification, pharmacological validation, and medicinal chemistry optimization of small molecules targeting GCase, ultimately leading to a viable therapeutic for GD and PD.

Expert consensus on the clinical application strategy of NIPT2.0, a new-generation non-invasive prenatal screening technology

The new-generation non-invasive prenatal screening technology (NIPT2.0) is a new method successfully realized in recent years based on high-throughput sequencing to synchronously and accurately detect fetal chromosomal aneuploidies, microdeletion/microduplication syndromes and dominantly inherited monogenic disorders. NIPT2.0 can circumvent the shortcomings of previous non-invasive prenatal screening techniques (NIPT and NIPT Plus) including incapability to detect fetal monogenic disorders, insufficient accuracy of detection and low positive predictive values for certain chromosomal abnormalities (in particular trisomy 13, sex chromosomal abnormalities, and small-segment microdeletions and microduplication syndromes). How to apply NIPT2.0 reasonably and normatively to maximize its clinical value has become an issue which requires clarification. The Reproductive Health Branch of the Chinese Maternal and Child Health Care Association and the Genetic Diagnosis Branch of the Genetics Society of China have organized experts to fully discuss and jointly drafted this consensus, which has put forwards suggestions over the clinical application strategy for NIPT2.0, including the scope of application, target disease, pre-test consultation, clinical application pathway, post-test genetic counseling and intervention, quality control and limitations, for the reference by peers, with a view to standardize its application and provide better clinical service.

In silico identification and virtual screening to discover potent therapeutic phytochemicals against CMT2A

Charcot-Marie-Tooth (CMT2A) neuropathies are a set of monogenic diseases that affect the peripheral nervous system. The pathogenesis of CMT2A, a disease caused by genetic mutations, is linked to impaired mitochondrial dynamics and axonal biology. Therapeutic options are still limited, with only a few drugs and other authorized or underdeveloped approaches. A ligand-based virtual screening methodology was used to identify the potential MFN promoters. The natural compound subset of the ZINC database (n = 559600) was obtained and filtered using a ligand-based virtual screening technique. The top 200 compounds were identified to have more than four features that matched the target compound. Pyrx software was used to analyze the molecular docking. Based on the number and type of important binding interactions and docking results, we selected top-20 compounds with the best binding affinities for the targeted protein. 3D-QSAR analyses were performed on potential ligands identified through molecular docking analyses to predict biological activity. The pEC50 and docking scores were used to identify the potential drugs. The ADMET analysis was used to assess the kinetic characteristics of the top two drugs. According to molecular dynamics simulation, the top compound ZINC000005313168 showed high conformational stability. Based on docking results and MD findings, the best in silico hits among the compounds investigated was ZINC000005313168. These findings suggest that the compound ZINC000005313168 could be used to treat CMT2A disease. Further in vivo and in vitro studies are required to consider the present analyses.

Genetically humanized phenylketonuria mouse model as a testing tool for human genome editing in fertilized eggs.

Targeted genome editing has made significant advancements; however, safety and ethical issues have not been fully elucidated, resulting in strict control of the technique. We tested genome editing tools on gametes from a genetically humanized mouse model using a phenylketonuria (PKU) mouse model to gain insights into genome editing in human embryos. The human PKU mouse model PahhR111X mice was generated. The junctional region between exon 3 and intron 3 of Pah was replaced with a 120 bp corresponding human PAH sequence, including the pathogenic common variant c.331C > T in PahhR111X mice. PahhR111X mice successfully recapitulated the PKU phenotype and showed cognitive dysfunction and depressive-like behavior, which are observed in human patients with PKU. Genome editing was applied to fertilized eggs of PahhR111X mice utilizing sgRNA that targets the human sequence. Mice with the corrected allele exhibited normal serum phenylalanine levels. Through genome editing, we validated the utility of sgRNA. The genetically humanized mouse model suggested that germ-line genome editing of the pathogenic variant may be feasible for monogenic disorders by revealing the recovery of the phenotype; however, there are remaining issues with the tool, including its efficiency and accuracy. This genome editing protocol using a genetically humanized mouse model will provide insights for improving current issues and contribute to the establishment of heritable human genome editing protocols.

Genetic architecture reconciles linkage and association studies of complex traits.

Linkage studies have successfully mapped loci underlying monogenic disorders, but mostly failed when applied to common diseases. Conversely, genome-wide association studies (GWASs) have identified replicable associations between thousands of SNPs and complex traits, yet capture less than half of the total heritability. In the present study we reconcile these two approaches by showing that linkage signals of height and body mass index (BMI) from 119,000 sibling pairs colocalize with GWAS-identified loci. Concordant with polygenicity, we observed the following: a genome-wide inflation of linkage test statistics; that GWAS results predict linkage signals; and that adjusting phenotypes for polygenic scores reduces linkage signals. Finally, we developed a method using recombination rate-stratified, identity-by-descent sharing between siblings to unbiasedly estimate heritability of height (0.76 ± 0.05) and BMI (0.55 ± 0.07). Our results imply that substantial heritability remains unaccounted for by GWAS-identified loci and this residual genetic variation is polygenic and enriched near these loci.

8184 A Case With Primary Hyperparathyroidism Caries A New Variant Of Uncertain Significance (VUS) Of The Multiple Endocrine Neoplasia Type 1 (MEN1) Gene

Abstract Disclosure: E. Caliskan Guzelce: None. E. Fieg: None. C. Pallias: None. Background: Multiple endocrine neoplasia type 1 (MEN1) is a rare, autosomal dominant disorder caused by mutations in the MEN1 tumor suppressor gene. MEN1 syndrome is classically characterized by a predisposition to tumors of the parathyroid glands, anterior pituitary, and pancreatic islet cells. However, the clinical spectrum of this disorder has been expanded: carcinoid tumors,adrenal adenomas and lipomas are more common than in the general population.We report a case whose personal and family history is highly suggestive of and consistent with a monogenic disorder such as MEN1, also found to be a carrier of a new variant of uncertain significance (VUS) of the MEN1 gene. A study performed with the French Universal Mutation Database (UMD) for the MEN1 gene showed that one-third of the missense MEN1 variants were VUSs, mainly due to the lack of clinical and segregation data. Therefore, it is very important to identify and report the subjects with VUS of the MEN1 gene. Case report: 68-year-old female with a past medical history significant for hypertension, type 2 diabetes mellitus, hyperlipidemia, CKD stage 4, and nephrolithiasis, GERD who presented with chief complaints of nausea and upper abdominal/epigastric pain and dark stools and found to have moderate hypercalcemia c/w primary hyperparathyroidism, several pancreatic cystic lesions most likely branch duct intraductal papillary mucinous neoplasms, and multinodular goiter and adrenal adenoma. Family history significant for recurrent hyperparathyroidism and nephrolithiasis; her daughter and brother had nephrolithiasis; her daughter has undergone parathyroidectomy twice. The patient's mother died at a young age because of gastric ulcer-related complications. Hyperparathyroidism-related genes were analyzed; AP2S1, CASR, CDC73, CDKN1B, GNA11, RET, MEN1, and only a Variant of Uncertain Significance, c.247_249dup (p.Leu83dup), was identified in MEN1 gene. The patient’s daughter and granddaughter are found to have the same mutation. Conclusion: This variant, c.247_249dup, results in the insertion of 1 amino acid(s) of the MEN1 protein (p. Leu83dup), but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (gnomAD no frequency). The literature has not reported this variant in individuals affected with MEN1-related conditions. Presentation: 6/3/2024

8131 A Rare Case of Autoimmune Polyendocrine Syndrome; a Menopause Despite Replacement Therapy

Abstract Disclosure: M.E. Chacon Cruz: None. M. Sanchez Cordero: None. R.M. Roman Torres: None. G. Guerra Velazquez: None. Polyendocrinopathy is a heterogeneous group of disorders leading to dysfunction of multiple endocrine glands and other tissues. The syndromes can occur in patients from early infancy to old age and new components of a given syndrome can appear throughout life. APS can be classified into APS type 1 and APS2-4. APS-1 is a rare monogenic autosomal recessive autoimmune disorder consisting of the triad of chronic mucocutaneous candidiasis, hypoparathyroidism and adrenal insufficiency. APS2 require presence of Addison disease, autoimmune thyroid disorder and type 1 diabetes. APS 3 requires presence of Thyroid autoimmune disease associated with other autoimmune diseases. APS4 is a combination of organ specific autoimmune disease non included in a previous group. Autoimmune oophoritis is found in approximately 4 percent of females who presented with spontaneous primary ovarian insufficiency and may occur in type I and II syndromes of polyglandular autoimmune failure. This is the case of 44 year old female patient with history of hypertension, hypoparathyroidism diagnose at the age of 9 year old, vitiligo and premature ovarian failure diagnose at the age of 16 year old. Patient reported that started with multiple episodes of watery non bloody diarrhea and arthralgia. Patient went to her Pediatrician and they found hypocalcemia hyperphospathemia. Patient mineral was replaced with medication and then followed by pediatric endocrinologist. Patient continues with normal life, but menstrual periods had not started even at age 16th. Laboratory work up was done and premature ovarian failure was diagnosed after that, patient started with progesterone and estrogen to induce menstrual periods. Menstrual periods began regularly and monthly. Patient continues taking medication regularly, phoslo, calcitriol, progestin and estradiol without problem until this year that despite regular medication, started with signs and symptoms of menopause with irregular menstrual periods, palpitations hot flashes, sweating, anxiety and sleep problems. Patient met criteria for APS4 due to combination of organ specific autoimmune disease such premature ovarian failure, vitiligo and hypoparathryroidism. This case is extremely important since despite the fact that there is no family history of either endocrinological or autoimmune diseases, our patient debuts throughout her life with several autoimmune diseases, such as premature ovarian failure and vitiligo. Patient had Schedule appointment with gynecologist who increased the dose of progestin and estradiol. This case highlights the importance of being vigilant about new components of a syndrome developing at different times though a patient's life. As described, autoimmune diseases commonly are related to other diseases, but without a good clinical history and physical examination could be misdiagnosed affecting the quality of life of those patients. Presentation: 6/2/2024

8488 Sex-Specific Differences in an Alstrom Syndrome Mouse Model

Abstract Disclosure: Y. Carcamo-Bahena: None. J. Youn: None. E. Lartigue: None. S. Sisley: None. Background: Alström syndrome is a monogenic autosomal recessive disorder caused by loss of the ALMS1 gene that affects 1 in 1 million. Loss of a functional ALMS1 protein leads to global disorganization of microtubules. Patients are affected by progressive vision and hearing loss and are at risk of developing obesity and type 2 diabetes. Aside from reproductive system anomalies, no clinical reports have identified sex-specific difference in patients with Alström syndrome. Methods: Male and female Alms1tvrm[1]02/tvrm[1]02 (null), Alms1tvrm[1]02/+ (heterozygous) and wildtype littermate mice were weaned onto standard chow diet. At 16 weeks of age, they were changed to a 45% high fat diet (HFD). Weekly body weights were collected and intraperitoneal glucose tolerance tests (GTTs, 1.5 g/kg D20W) were performed at three different time points (11, 16, 25 weeks of age). Results:Alms1 null mice were heavier than wildtype and heterozygous mice on standard chow diet. In males, significant changes in weight gain in null mice occurred by 10 weeks compared to wildtype and heterozygous mice (p<0.05). In females, compared to null, this change was observed by 13 weeks (p<0.05). Although female mice are typically protected from diet-induced obesity, the null females weighed the same as the null males (65.0 ± 2.0 vs 67.7 ± 2.8 g) after 9 weeks on HFD. We observed sex and diet specific differences in GTT outcomes. On chow diet, Alms1 deficiency did not affect glucose levels during a GTT in female mice. However, after 9 weeks of HFD (25 weeks of age), baseline fasting glucose levels were higher in the null females compared to wildtype (p<0.05) and heterozygotes (p<0.01). Additionally, the GTT curve was monophasic, indicating onset of diabetes whereas wildtype and heterozygotes (p<0.0001) had normal curves. Null male mice showed an impaired glucose response at 11 weeks of age on chow diet compared to wildtype and heterozygous males (p<0.001) and by 16 weeks, the GTT glucose curve for Alms1 null mice was monophasic. After 9 weeks of HFD, no differences were observed in glucose levels during a GTT. Conclusions: We observed sex-specific differences in this Alms1 null mouse model related to body weight and glucose tolerance with male null mice exhibiting earlier obesity and impaired glucose tolerance and female mice showing more pronounced effects on a HFD. Future research should investigate if these sex-specific effects alter responses to dietary or pharmaceutical interventions. Presentation: 6/1/2024

7238 A rare cause of primary ovarian failure in an adolescent due to a genetic mutation in mitochondrial poly-A-polymerase (mTPAP) mRNA

Abstract Disclosure: J. Epstein: None. S. Veera: None. J. Pappas: None. B.C. Shah: None. Primary ovarian insufficiency (POI) is a dysfunction or loss of ovarian follicles with associated amenorrhea. While most causes are idiopathic, approximately 15% of POI cases are due to single gene or chromosomal abnormalities, such as X chromosome abnormalities. Many of these nuclear genes encode for proteins that function within the mitochondria. Mitochondrial disorders affect tissues with high energy demand, such as the neurological, skeletal, cardiac, and endocrine systems. Furthermore, mature ovaries have a relatively higher concentration of mitochondria, which play a role in cellular respiration along with steroidogenesis. Mutations that disrupt these pathways can therefore lead to ovarian dysfunction. We present a case of a 17-year-old female with concern for primary amenorrhea. She underwent pubarche at age 12 years and thelarche at 14 years, with slowed progression. Height Z score was -1.61 and weight Z score was -0.41. Lab work at presentation was significant for LH 18.6 IU/L (N 2.4-12.6 IU/L), FSH 43.9 IU/L (N 1.1-9.6 IU/L), low estradiol <2.5 pg/mL (N 30-100 pg/mL), low total testosterone 8.3 ng/dL (N 15-31 ng/dL), unremarkable HbA1C, cortisol, thyroid levels, and a 46 XX karyotype. Pelvic ultrasound showed small ovarian volumes with a 1.9 cc right ovary, 1.5 cc left ovary consistent with lack of hormonal stimulation, and uterus length of 4.9 cm (N > 4 cm) consistent with early hormonal stimulation. She was started on transdermal estrogen replacement. Past medical history included stable pericardial effusion, episodes of supraventricular tachycardia, pre-cataracts, speech delays, mild learning disabilities, spastic diplegia, progressive gait abnormalities, ligamentous laxity, and recurrent patellar dislocations requiring multiple orthopedic limb surgeries. Family history was significant for parental consanguinity as first cousins. As the etiology of the POI remained unknown, genetic testing was completed. Whole exome sequencing (WES) revealed a homozygous pathogenic variant in the MTPAP gene: p.(Leu495Arg) (CTG>CGG): c.1484 T>G in exon 9 on chromosome 10p11.23. MTPAP, also known as SPAX4, TENT6, or PAPD1, is a nuclear-encoded polymerase involved in synthesizing the 3’ poly(A) tail of mitochondrial transcripts as well as in mRNA degradation. She was diagnosed with autosomal recessive MTPAP-related neurodevelopmental and movement disorder. Monogenic disorders affecting mitochondrial function are rare causes of POI. A high index of suspicion should be raised when a constellation of neurological, musculoskeletal, and cardiac problems co-exist. WES can be a very useful tool for uncovering rare genetic disorders. Further studies are needed to clarify details of organ specific mitochondrial dysfunction and possible therapeutics in individuals affected with MTPAP-related neurodevelopmental and movement disorders. Presentation: 6/1/2024

7086 Disrupted Mitochondrial Function in Alström Syndrome- A Monogenic Model of Insulin Resistance and Obesity

Abstract Disclosure: S. Ali: None. S. Heising: None. V. Veeranna: None. A. Vincent: None. G.S. Xavier: None. T. Geberhiwot: None. Alström syndrome (ALMS) is a rare monogenic disease typified by severe insulin resistance (IR) and obesity. IR and obesity are cardinal features of metabolic syndrome. The metabolic effects of insulin at key target tissues leads to metabolic haemostasis by promoting glucose and lipid uptake and metabolism to generate energy in cells. Although insulin is a major regulator of fuel metabolism, its effects on mitochondrial ATP production in severe insulin resistance are unclear. RNASeq data from adipose tissue (AT) from patients with ALMS show downregulation of the expression of genes associated with mitochondrial respiratory chain function, pointing towards possible altered mitochondrial function in ALMS. We therefore undertook a detailed assessment of mitochondrial oxidative phosphorylation capacity (OXPHOS) in skeletal muscle (SM) in ALMS. We performed SM biopsy in 10 ALMS and 10 healthy control volunteers that were age, gender and Body Mass Index matched. The SM was subjected to high resolution respirometry, the gold standard method to quantify mitochondrial function ex vivo, using OROBOROS Oxygraph -2k (O2k) system. Overall OXPHOS was higher in control SM compared to ALMS, with maximal respiration of 62.96±19.2 and 44.24 ± 12.53 pmol/(s*mg), respectively (p<0.05).Reduced oxygen influx was observed in ALMS SM in comparison to controls for fatty acid ß oxidation (6.7±5.96 vs 7.87±2.7 pmol/(s*mg);p<0.05, at complex I (19.4 ± 8.98 vs 29.7 ±5.3 pmol/(s*mg);p<0.05, and at complex II (34.98 ±11.75 vs 53.52± 13.2 pmol/(s*mg) ;p<0.05. Mitochondrial membrane integrity was unaffected during these experiments. Therefore, our analysis unveils a consistent reduction in mitochondrial respiration across all the electron transport pathway. This noteworthy finding suggests impairment in respiratory function and the electron transport chain in mitochondria, a crucial aspect of cellular energy metabolism. Several studies have previously linked IR with mitochondrial dysfunction, where insulin-resistant rodents and humans have shown blunted mitochondrial response to ATP generation. Our results align with this body of evidence emphasizing the significance of investigating the underlying mechanism contributing to this phenomenon. These findings could pave the way to exploring potential mitochondrial-targeted therapies to restore mitochondrial function and therefore, improve insulin sensitivity to tackle IR in ALMS. Presentation: 6/2/2024

8393 Low Polygenic Risk Score For Autoimmune Addison’s Disease Identifies Misdiagnosed Cases of Monogenic Primary Adrenal Insufficiency

Abstract Disclosure: M. Aranda Guillen: None. I. Botusan: None. V. Fernando: None. E. Røyrvik: None. A. Bøe Wolff: None. S. Johansson: None. E.S. Husebye: None. S. Bensing: None. O. Kampe: None. D. Eriksson: None. Background: Primary adrenal insufficiency (PAI) is sometimes misdiagnosed as autoimmune Addison's disease (AAD), affecting clinical management and genetic counselling. We tested a polygenic risk score (PRS) for AAD (PRS14AAD) as a tool to reevaluate disease etiology and identify patients misdiagnosed with AAD. Methods: We calculated the PRS14AAD in a cohort of patients diagnosed with AAD but lacking 21-hydroxylase autoantibodies (n=124). Patients with low genetic susceptibility to AAD were selected for whole-genome sequencing to detect potential monogenic causes (n=35). Results: Among the 35 patients, monogenic PAI was diagnosed in 5 (14%) and suspected in 3 additional cases (9%). Three out of the 5 patients diagnosed with monogenic PAI developed the disease in adulthood, indicating late-onset monogenic disease associated with hypomorphic genetic variants. Conclusion: A PRS for AAD can help identify potential monogenic cases, regardless of the age at diagnosis. Early identification of the underlying cause of PAI enables accurate management and correct genetic counselling. Presentation: 6/2/2024

Monogenic Kidney Diseases in Adults With Chronic Kidney Disease (CKD).

According to current evidence, every 10th to 11th adult with chronic kidney disease (CKD) has a monogenic disease of the kidney. This review is based on reported studies in which molecular genetic diagnostic techniques were used to investigate monogenic kidney diseases in adults with CKD. The studies were identified by a selective literature search using predefined criteria. In 12 selected studies, diagnostic variants of 179 different genes were identified in 1467 out of 6607 study participants with CKD (22.2%). More than 60% of these variants affected 8 genes (PKD1, PKD2, COL4A3, COL4A4, COL4A5, UMOD, MUC1, HNF1B). Three diseases are associated with these genes: autosomal dominant polycystic kidney disease (ADPKD), Alport syndrome, and autosomal dominant tubulo-interstitial kidney disease (ADTKD). Physicians treating patients with CKD should be alert to the presence of any red flags, such as onset at a young age, a positive family history, or hematuria of unknown cause. When a genetic etiology is suspected, a specialized work-up is indicated, often including a molecular genetic investigation. A positive genetic finding usually leads to a modification of the patient's specific diagnosis and/or treatment. Awareness of the high prevalence of monogenic kidney diseases in adults with CKD and alertness to their suggestive clinical features are crucial for the timely initiation of targeted diagnostic testing. The molecular genetic identification of these diseases is a prerequisite for appropriate patient management.

Current research status and clinical applications of noninvasive preimplantation genetic testing: A review.

Noninvasive preimplantation genetic testing (ni-PGT) is conducted by obtaining genetic information from embryos through the analysis of free DNA released by embryos in spent embryo culture medium or blastocoel fluid. Compared to conventional preimplantation genetic testing relying on trophectoderm biopsy, ni-PGT is characterized by its noninvasiveness. It has demonstrated early advancements in the detection of embryonic chromosomal aneuploidies and the diagnosis of monogenic diseases, showcasing considerable potential for clinical application. However, there are substantial controversies in the literature concerning the reliability of ni-PGT, the source of cell-free DNA, and maternal contamination. This paper elaborates on the principles, research advancements, effectiveness, and limitations of ni-PGT to provide a basis for clinical applications.

Effects of ovarian stimulation on embryo euploidy: an analysis of 12874 oocytes and 3106 blastocysts in cycles with preimplantation genetic testing for monogenic disorders.

Does ovarian stimulation and the ovarian response affect embryo euploidy? Ovarian stimulation and the ovarian response in women undergoing preimplantation genetic testing for monogenic disorders (PGT-M) cycles did not affect the rates of blastocyst euploidy. Whether or not ovarian stimulation in IVF-embryo transfer has potential effects on embryo euploidy is controversial among studies for several reasons: (i) heterogeneity of the study populations, (ii) biopsies being performed at different stages of embryo development and (iii) evolution of the platforms utilized for ploidy assessment. Patients who undergo PGT-M cycles typically have no additional risks of aneuploidy, providing an ideal study population for exploring this issue. A retrospective cohort study including embryos undergoing PGT-M was conducted at a single academically affiliated fertility clinic between June 2014 and July 2021. A total of 617 women with 867 PGT-M cycles involving 12874 retrieved oocytes and 3106 trophectoderm biopsies of blastocysts were included. The primary outcome of the study was median euploidy rate, which was calculated by dividing the number of euploid blastocysts by the total number of biopsied blastocysts for each cycle. Secondary outcomes included the median normal fertilization rate (two-pronuclear (2PN) embryos/metaphase II oocytes) and median blastulation rate (blastocyst numbers/2PN embryos). Comparable euploidy rates and fertilization rates were observed across all age groups, regardless of variations in ovarian stimulation protocols, gonadotropin dosages (both the starting and total dosages), stimulation durations, the inclusion of human menopausal gonadotrophin supplementation, or the number of oocytes retrieved (all P > 0.05). Blastulation rates declined with increasing starting doses of gonadotropins in women aged 31-34 years old (P = 0.005) but increased with increasing gonadotrophin starting doses in women aged 35-37 years old (P = 0.017). In women aged 31-34, 35-37, and 38-40 years old, blastulation rates were significantly reduced with increases in the number of oocytes retrieved (P = 0.001, <0.001, and 0.012, respectively). Limitations include the study's retrospective nature and the relatively small number of patients of advanced age, especially patients older than 40 years old, leading to quite low statistical power. Second, as we considered euploidy rates as outcome measures, we did not analyze the effects of ovarian stimulation on uniform aneuploidy and mosaicism, respectively. Finally, we did not consider the effects of paternal characteristics on embryo euploidy status due to the fact that blastocyst aneuploidy primarily originates from maternal meiosis. However, sperm factors might have an effect on embryo development and the blastulation rate, and therefore also the number of blastocysts analyzed. The exclusion of patients with severe teratozoospermia and the fact that only ICSI was used as the insemination technique for women undergoing PGT-M contributed to minimize the effect of paternal factors. Ovarian stimulation and response to stimulation did not affect blastocyst euploidy rates in women undergoing PGT-M cycles. However, in women aged 31-40 years old, there was a significant decline in blastulation rates as the number of retrieved oocytes increased. This study was supported by the National Natural Science Foundation of China (Grant No. 81701407, 82301826); the National Key Research and Development Program of China (2022YFC2702901, 2022YFC2703004); China Postdoctoral Science Foundation (2022M710261), and China Postdoctoral Innovation Talent Support Program (BX20220020). There is no conflict of interest. N/A.

Systematic characterization and efficient prediction of cobalamin C deficiency clinical phenotypes using network analysis and deep learning on multi-omics data

As a monogenic disease, cobalamin C (cblC) deficiency lacks a clear correlation between gene pathogenic mutations and its spectrum of disease phenotypes, necessitating the understanding of molecular mechanisms how diverse clinical phenotypes emerge. This work aimed to disentangle the phenotypic complexity of cblC deficiency via network analysis and deep learning on multi-omics (proteomics and metabolomics) data. For this purpose, a novel computational framework was developed to systematically characterize and efficiently predict clinical phenotypes of cblC deficiency utilizing a Connect the Dots (CTD)-based Hybrid data Structural Representation of each patient and graph convolutional network (GCN)-based Multi-Omics Learning (CTDHSR-GCNMOL). CTD algorithm enabled the identification of relevant perturbed proteins or metabolites and the construction of clinical phenotype-specific co-perturbation network. GCN allowed efficient learning of subtle change patterns across clinical phenotypes not only depending on the hybrid feature description (Euclidean structure hybridized with non-Euclidean structure) of each patient but on the interaction exploration between patients offered by sample similarity network. Investigated by three clinical phenotypes (epilepsy, developmental delay and metabolic syndrome), the results showed that CTDHSR-GCNMOL identified the subsets of perturbed proteins or metabolites highly specific to each clinical phenotype and established each main disease module (network) for systematic characterization. For proteomics, epilepsy was characterized by the dysregulation of reported TAGLN2, SH3BGRL3 and LTA4H, and developmental delay was characterized by the dysregulation of reported HSP90AB1, PRDX1, GDI2, VIM, PNP and BLVRA with high confidence (selection frequencies). For untargeted metabolomics in negative ion mode, the disease status of metabolic syndrome could be well interpreted by the disturbed pathways of the top-ranked 20 perturbed metabolites all of which have been reported to be closely related with its pathogenesis in previous studies. These disturbed pathways involved butanoate metabolism, purine metabolism, alanine, aspartate and glutamate metabolism, pyrimidine metabolism, fructose and mannose metabolism, galactose metabolism, amino sugar and nucleotide sugar metabolism, and steroid hormone biosynthesis. Based on the hybridization of the abundances of perturbed proteins and metabolites with the topological structures of patient-specific perturbation network, CTDHSR-GCNMOL yielded desired prediction performance across three clinical phenotypes and outperformed the traditional block PLSDA. All these findings verified the effectiveness of CTDHSR-GCNMOL in gaining useful insights into the phenotypic complexity of cblC deficiency and guiding its targeted treatment strategies.

Natural History and Clinicopathological Associations of TRPC6-Associated Podocytopathy.

Understanding the genetic basis of human diseases has become integral to drug development and precision medicine. Recent advancements have enabled the identification of molecular pathways driving diseases, leading to targeted treatment strategies. The increasing investment in rare diseases by the biotech industry underscores the importance of genetic evidence in drug discovery and approval processes. Here we studied a monogenic Mendelian kidney disease, TRPC6-associated podocytopathy (TRPC6-AP), to present its natural history, genetic spectrum, and clinicopathological associations in a large cohort of patients with causal variants in TRPC6, in order to help define the specific features of disease and further facilitate drug development and clinical trials design. the study involved 64 individuals from 39 families with TRPC6 causal missense variants. Clinical data, including age of onset, laboratory results, response to treatment, kidney biopsy findings, and genetic information, were collected from multiple centers nationally and internationally. Exome or targeted sequencing was performed and variant classification was based on strict criteria. Structural and functional analyses of TRPC6 variants were conducted to understand their impact on protein function. In depth re-analysis of light and electron microscopy specimens for 9 available kidney biopsies was conducted to identify pathological features and correlates of TRPC6-AP. Large-scale sequencing data did not support causality for TRPC6 protein-truncating variants. We identified 21 unique TRPC6 missense variants, clustering in three distinct regions of the protein, and with different effects on TRPC6 3D protein structure. Kidney biopsy analysis revealed FSGS patterns of injury in most cases, along with distinctive podocyte features including diffuse foot process effacement and swollen cell bodies. The majority of patients presented in adolescence or early adulthood but with ample variation (average 22, SD ± 14 years), with frequent progression to kidney failure but with variability in time between presentation and ESKD. This study provides insights into the genetic spectrum, clinicopathological associations, and natural history of TRPC6-AP.

Importance of Copy Number Variant Analysis in Patients with Monogenic Kidney Diseases: Insights from 8 Years of Experience in an Expert Centre's Genome Diagnostic Laboratory

Importance of Copy Number Variant Analysis in Patients with Monogenic Kidney Diseases: Insights from 8 Years of Experience in an Expert Centre's Genome Diagnostic Laboratory

Study Protocol for LOMCAD Trial: Effect of Lomerizine Hydrochloride to Prevent Recurrence of Cerebral Ischemic Events in CADASIL Patients

ObjectivesCerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is one of the most common monogenic cerebral small vessel diseases. Our previous observational study suggested that lomerizine hydrochloride, a calcium channel blocker approved in Japan in 1999 for the prevention of migraine headaches, is also effective for preventing recurrent ischemic stroke in CADASIL patients. The aim of this study (LOMCAD trial) is to verify the efficacy of lomerizine hydrochloride. Materials and MethodsThis is a multicenter, prospective, single-arm trial, using a historical control for comparison. CADASIL patients with a history of two or more cerebral ischemic events within the last two years will be administered lomerizine hydrochloride (5-mg tablet twice daily) for 24 months. The primary endpoint is symptomatic cerebral ischemic events during the 24-month period. Using our historical data and Bayesian sample size calculation based on a prior predictive distribution, the planned sample size was determined as 20 subjects. ConclusionWe have planned a clinical trial to verify the effectiveness of lomerizine hydrochloride as prophylaxis to prevent recurrent cerebral ischemic events in CADASIL patients. RegistrationThe LOMCAD trial has been registered in the Japan Registry of Clinical Trials (jRCTs051220072, https://jrct.niph.go.jp/latest-detail/jRCTs051220072).

Genome Editing Therapy for the Blood: Ex Vivo Success and In Vivo Prospects.

Hematopoietic stem cells (HSCs) provide the body with a continuous supply of healthy, functional blood cells. In patients with hematopoietic malignancies, immunodeficiencies, lysosomal storage disorders, and hemoglobinopathies, therapeutic genome editing offers hope for corrective intervention, with even modest editing efficiencies likely to provide clinical benefit. Engineered white blood cells, such as T cells, can be applied therapeutically to address monogenic disorders of the immune system, HIV infection, or cancer. The versatility of CRISPR-based tools allows countless new medical interventions for diseases of the blood, and rapid ex vivo success has been demonstrated in hemoglobinopathies via transplantation of the patient's HSCs following genome editing in a laboratory setting. Here we review recent advances in therapeutic genome editing of HSCs and T cells, focusing on the progress in ex vivo contexts, the promise of improved access via invivo delivery, as well as the ongoing preclinical efforts that may enable the transition from ex vivo to invivo administration. We discuss the challenges, limitations, and future prospects of this rapidly developing field, which may one day establish CRISPR as the standard of care for some diseases affecting the blood.

Genetic variant profiling of neonatal diabetes mellitus in Iranian patients: Unveiling 58 distinct variants in 14 genes.

Neonatal diabetes mellitus (NDM) is a rare non-immunological monogenic disorder characterized by hyperglycemic conditions primarily occurring within the first 6 months of life. The majority of cases are attributed to pathogenic variants in genes affecting beta-cell survival, insulin regulation, and secretion. This study aims to investigate the genetic landscape of NDM in Iran. We recruited a total of 135 patients who were initially diagnosed with diabetes at <12 months of age in Iran and referred to pediatric endocrinology clinics across the country. These patients underwent genetic diagnostic tests conducted by the Exeter Molecular Genetics Laboratory in the UK. The pathogenic variants identified were sorted and described based on type, pathogenicity (according to ACMG/AMP criteria), novelty, and the affected protein domain. Genetic defects were identified in 93 probands, presenting various pathogenic abnormalities associated with NDM and its associated syndromes. 76% of the patients were born as a result of consanguineous marriage, and a familial history of diabetes was found in 43% of the cases. A total of 58 distinct variants in 14 different genes were discovered, including 20 variants reported for the first time. Causative variants were most frequently identified in EIF2AK3, KCNJ11, and ABCC8, respectively. Notably, EIF2AK3 and ABCC8 exhibited the highest number of novel variants. These findings provide valuable insights into the genetic landscape of NDM in the Iranian population and contribute to the knowledge of novel pathogenic variants within known causative genes.