Mild Disease Phenotype Research Articles

SMN1 c.5C>G (p.Ala2Gly) missense variant, a challenging molecular SMA diagnosis associated with mild disease, preserves SMN nuclear gems in patient-specific fibroblasts.

Spinal muscular atrophy (SMA) is caused by homozygous loss of the SMN1 gene with SMN2 gene copy number correlating with disease severity. Rarely SMA is caused by a deletion on one allele and a pathogenic variant on the other. The pathogenic missense variant c.5C>G (p.Ala2Gly) correlates with a mild disease phenotype that does not correlate with SMN2 copy number. In a mouse model the c.5C>G transgene produces SMN that is thought to form partially functional SMN complexes, but levels in humans have not yet been investigated. We identified two patients with mild SMA caused by a heterozygous deletion of SMN1 and the heterozygous variant, c.5C>G. Molecular findings were confirmed with deletion/duplication analysis and Sanger sequencing. Skin fibroblasts were collected and cultured, and SMN expression was analyzed using immunofluorescence. Two patients with slowly progressing mild weakness were confirmed to have heterozygous pathogenic missense variant c.5C>G and a heterozygous deletion of SMN1. Their clinical presentation revealed much milder disease progression than patients with matched SMN2 copy number. Analysis of the patients' fibroblasts revealed much higher numbers of SMN nuclear complexes than a patient with a homozygous SMN1 deletion and matched SMN2 copy number. These case reports reinforce that the rare c.5C>G variant causes mild disease. Furthermore, the analysis of SMA nuclear gems in patient samples supports the theory that the p.Ala2Gly SMN can form partially functional SMN complexes that may carry out essential cellular functions and result in mild disease.

Exploring relief for Behçet's disease refractory oral ulcers: a comparison of TNF inhibitors versus apremilast.

Oral and genital ulcers are the hallmark manifestation of Behçet's disease (BD), significantly impacting patients' quality of life. Our study focuses on comparing the effectiveness and safety of TNF inhibitors (TNFis) and apremilast in controlling oral ulcers of BD, aiming to provide evidence-based guidance for physicians in selecting appropriate treatment modalities. A retrospective analysis was performed on BD patients treated between December 2016 and December 2021 with TNFis or apremilast for refractory oral ulcers. The study assessed treatment response by the absence of oral ulcers at 3 and 6 months, with additional evaluations for genital ulcers and articular involvement. The study included 78 patients, equally allocated between TNFis and apremilast treatments. Both groups showed significant oral ulcer reduction at 3 (p< 0.001) and 6 months (p= 0.01) with no significant difference between the treatments. Apremilast had a notable corticosteroid-sparing effect by the 3-month follow-up, persisting through 6 months. Both treatments were equally effective in reducing genital ulcers, with TNFis showing greater effectiveness in addressing articular involvement. Apremilast had a higher discontinuation rate due to gastrointestinal side effects. TNFis and apremilast are both effective for treating BD refractory oral ulcers. While TNFis may offer broader benefits for other disease manifestations, apremilast is distinguished by its corticosteroid-sparing effect, especially for patients with a milder disease phenotype. Treatment selection should consider individual disease severity and clinical features to ensure a personalized and effective management strategy.

Evolving Role of Viltolarsen for Treatment of Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is one of the most prevalent X-linked inherited neuromuscular disorders, with an estimated incidence between 1 in 3500 and 5000 live male births. The median life expectancy at birth is around 30years due to a rapid and severe disease progression. Currently, there is no cure for DMD, and the standard of care is mainly palliative therapy and glucocorticoids to mitigate symptoms and improve quality of life. Recent advances in phosphorodiamidate morpholino antisense oligonucleotide (PMO) technology has proven optimistic in providing a disease-modifying therapy rather than a palliative treatment option through correcting the primary genetic defect of DMD by exon skipping. However, as a result of the high variance in mutations of the dystrophin gene causing DMD, it has been challenging to tailor an effective therapy in most patients. Viltolarsen is effective in 8% of patients and accurately skips exon53, reestablishing the reading frame and producing a functional form of dystrophin and milder disease phenotype. Results of recently concluded preclinical and clinical trials show significantly increased dystrophin protein expression, no severe adverse effects, and stabilization of motor function. In summary, viltolarsen has provided hope for those working toward giving patients a safe and viable treatment option for managing DMD. This review summarizes an overview of the presentation, pathophysiology, genetics, and current treatment guidelines of DMD, pharmacological profile of viltolarsen, and a summary of the safety and efficacy with additional insights using recent clinical trial data.

The changing landscape of acromegaly- an epidemiological perspective.

Acromegaly is a rare disease and thus challenging to accurately quantify epidemiologically. In this comprehensive literature review, we compare different approaches to studying acromegaly from an epidemiological perspective and describe the temporal evolution of the disease pertaining to epidemiological variables, clinical presentation and mortality. We present updated epidemiological data from the population-based Danish cohort of patients with acromegaly (AcroDEN), along with meta-analyses of existing estimates from around the world.Based on this, we conclude that the incidence, prevalence and age at acromegaly diagnosis are all steadily increasing, but with considerable variation between studies. An increased number of incidental cases may contribute to the increase in incidence and age at diagnosis, respectively. The clinical features at presentation are trending toward a milder disease phenotype at diagnosis, and advances in therapeutic options have reduced the mortality of patients with acromegaly to a level similar to that of the general population. Moreover, the underlying cause of death has shifted from cardiovascular to malignant neoplastic diseases.

Divergent pathogenetic outcomes in BALB/c mice following Omicron subvariant infection

Following the emergence of B.1.1.529 Omicron, the SARS-CoV-2 virus evolved into a significant number of sublineage variants that possessed numerous mutations throughout the genome, but particularly within the spike glycoprotein (S) gene. For example, the BQ.1.1 and the XBB.1 and XBB.1.5 subvariants contained 34 and 41 mutations in S, respectively. However, these variants elicited largely replication only or mild disease phenotypes in mice. To better model pathogenic outcomes and measure countermeasure performance, we developed mouse adapted versions (BQ.1.1 MA; XBB.1 MA; XBB.1.5 MA) that reflect more pathogenic acute phase pulmonary disease symptoms of SARS-CoV-2, as well as derivative strains expressing nano-luciferase (nLuc) in place of ORF7 (BQ.1.1 nLuc; XBB.1 nLuc; XBB.1.5 nLuc). Amongst the mouse adapted (MA) viruses, a wide range of disease outcomes were observed including mortality, weight loss, lung dysfunction, and tissue viral loads in the lung and nasal turbinates. Intriguingly, XBB.1 MA and XBB.1.5 MA strains, which contained identical mutations throughout except at position F486S/P in S, exhibited divergent disease outcomes in mice (Ao et al., 2023). XBB.1.5 MA infection was associated with significant weight loss and ∼45 % mortality across two independent studies, while XBB.1 MA infected animals suffered from mild weight loss and only 10 % mortality across the same two independent studies. Additionally, the development and use of nanoluciferase expressing strains provided moderate throughput for live virus neutralization assays. The availability of small animal models for the assessment of Omicron VOC disease potential will enable refined capacity to evaluate the efficacy of on market and pre-clinical therapeutics and interventions.

Genomic Analysis of Sindbis Virus Reveals Uncharacterized Diversity within the Australasian Region, and Support for Revised SINV Taxonomy.

Sindbis virus (SINV) is a widely dispersed mosquito-borne alphavirus. Reports of Sindbis disease are largely restricted to northern Europe and South Africa. SINV is frequently sampled in Australian mosquito-based arbovirus surveillance programs, but human disease has rarely been reported. Molecular epidemiological studies have characterized six SINV genotypes (G1-G6) based on E2 gene phylogenies, mostly comprising viruses derived from the African-European zoogeographical region and with limited representation of Australasian SINV. In this study, we conducted whole genome sequencing of 66 SINV isolates sampled between 1960 and 2014 from countries of the Australasian region: Australia, Malaysia, and Papua New Guinea. G2 viruses were the most frequently and widely sampled, with three distinct sub-lineages defined. No new G6 SINV were identified, confirming geographic restriction of these viruses to south-western Australia. Comparison with global SINV characterized large-scale nucleotide and amino acid sequence divergence between African-European G1 viruses and viruses that circulate in Australasia (G2 and G3) of up to 26.83% and 14.55%, respectively, divergence that is sufficient for G2/G3 species demarcation. We propose G2 and G3 are collectively a single distinct alphavirus species that we name Argyle virus, supported by the inapparent or mild disease phenotype and the higher evolutionary rate compared with G1. Similarly, we propose G6, with 24.7% and 12.61% nucleotide and amino acid sequence divergence, is a distinct alphavirus species that we name Thomson's Lake virus.

Maladaptive Somatic Rescue in FLT3 Mutations of Suspected Germline Nature

Somatic genetic rescue (SGR) is a very rare process in which the occurrence of a somatic genetic event offsets the consequences of a germline (GL) mutation resulting in genetic mosaicism and, in some cases, in a milder disease phenotype 1. Acquired somatic mutations may be adaptive by countering the negative effects of the primary mutation ( e.g., improving hematopoiesis) or maladaptive by overcorrecting the initial impairment causing a different, possibly opposite, disease phenotype ( e.g., leading to the development of a myeloid malignancy) 2. Exemplary cases of the latter scenario are mainly represented by severe congenital neutropenia (SCN) cases developing AML as consequence of somatic CSF3R mutations 3 and, sporadically, by adaptive SGR in the context of germline GATA2 and secondary acquisition of somatic GATA2 mutation, counterbalancing the germline effect 4. Although SGR has been functionally demonstrated in these two above mentioned cases, given the molecular heterogeneity of myeloid neoplasia (MN) and the rarity of such genetic events, one can suspect that, in various clinical contexts, any mutation in any gene could be the SG rescuer. During our clinical experience, we encountered a case of a 57yo. woman with newly diagnosed aplastic anemia (AA) who was found to harbor a rare germline FLT3R311W mutation (VAF 50%; predicted to be a loss-of-function/hypomorphic alteration; Fig1) who subsequently evolved to MDS with monosomy 7. Coexisting somatic hits included non RUNT-homology domain, RUNX1P398L mutation (VAF 19%). Ultimately, the patient progressed to AML with emergence of a FLT3D825V (VAF 14%) and a NRASG13D (24%) lesions. In this case carrying GL FLT3 variant, biallelic somatic FLT3 mutation may represent maladaptive SGR. Therefore, we reviewed NGS sequencing results of 5,308 patients with MN and found three other suspected cases harboring GL variants in FLT3 gene, which inspired further investigations. In total we identified 3 additional cases (total of 4/5308 screened patients and among 248 somatic FLT3 mutations. Interestingly, the other case GL FLT3A680T occurred in a patient with AA (35yo.) who subsequently progressed to MDS and AML and acquired somatic NPM1L258fs, PTPN11 A72V, WT1 A365fs and most importantly, a somatic CSF3RL619S . The latter may represent an illustrative case of SGR, in analogy to AML developing in the context of SCN. In addition, 2 other cases with MDS or MDS/MPN were identified both presenting with cytopenia. A 53yo. woman diagnosed with MDS/MPN and GL FLT3L262F (gnomAD: 0.00000399) with a compound heterozygous somatic JAK2V617F mutation, again possibly serving as maladaptive clonal SGR event. Finally, we have identified a GL FLT3A291P mutation (VAF 60%, gnomAD frequency: 1.59×10-5) in a 58yo. man who eventually developed AML. In sum, similar to other phosphotyrosine receptor kinases (PTRKs) such as CSF3R, somatic FLT3 mutations may in rare biallelic cases correspond to SGR events of hypomorphic GL mutation or alternatively but not exclusively somatic mutations in other PTRK could evolve to reveal the GL FLT3 deficiency. Indeed, in another abstract by our group (Abstract#187151) we show that somatic FLT3 mutations can accompany GL variants in CSF3R, CSF2RB, and CSF1R. References 1 Revy P, Kannengiesser C, Fischer A. Somatic genetic rescue in Mendelian haematopoietic diseases. Nat Rev Genet. 2019 Oct;20(10):582-598. 2 Kennedy AL, Shimamura A. Genetic predisposition to MDS: clinical features and clonal evolution. Blood. 2019 Mar 7;133(10):1071-1085. 3 Germeshausen M, Kratz CP, Ballmaier M, Welte K. RAS and CSF3R mutations in severe congenital neutropenia. Blood. 2009 Oct 15;114(16):3504-5. 4 Catto LFB, Borges G, Pinto AL, Clé DV, Chahud F, Santana BA, Donaires FS, Calado RT. Somatic genetic rescue in hematopoietic cells in GATA2 deficiency.

Adenosinergic System and BDNF Signaling Changes as a Cross-Sectional Feature of RTT: Characterization of Mecp2 Heterozygous Mouse Females.

Rett Syndrome is an X-linked neurodevelopmental disorder (RTT; OMIM#312750) associated to MECP2 mutations. MeCP2 dysfunction is seen as one cause for the deficiencies found in brain-derived neurotrophic factor (BDNF) signaling, since BDNF is one of the genes under MeCP2 jurisdiction. BDNF signaling is also dependent on the proper function of the adenosinergic system. Indeed, both BDNF signaling and the adenosinergic system are altered in Mecp2-null mice (Mecp2-/y), a representative model of severe manifestation of RTT. Considering that symptoms severity largely differs among RTT patients, we set out to investigate the BDNF and ADO signaling modifications in Mecp2 heterozygous female mice (Mecp2+/-) presenting a less severe phenotype. Symptomatic Mecp2+/- mice have lower BDNF levels in the cortex and hippocampus. This is accompanied by a loss of BDNF-induced facilitation of hippocampal long-term potentiation (LTP), which could be restored upon selective activation of adenosine A2A receptors (A2AR). While no differences were observed in the amount of adenosine in the cortex and hippocampus of Mecp2+/- mice compared with healthy littermates, the density of the A1R and A2AR subtype receptors was, respectively, upregulated and downregulated in the hippocampus. Data suggest that significant changes in BDNF and adenosine signaling pathways are present in an RTT model with a milder disease phenotype: Mecp2+/- female animals. These features strengthen the theory that boosting adenosinergic activity may be a valid therapeutic strategy for RTT patients, regardless of their genetic penetrance.

The SF3B1 K666 Hotspot Mutation Confers Unfavourable Disease Risk across Major Myeloid Neoplasm Subgroups

SF3B1 is the most prevalent splicing factor mutated in myeloid neoplasms, detected in 20-30% of patients with myelodysplasia (MDS) and associated with a milder disease phenotype. SF3B1 mutations are typically single nucleotide variations occurring in hotspots in the HEAT domain. Disease-specific SF3B1 hotspot predilection is observed; for example, K700E is most common in MDS and R625 in uveal melanoma. The K666 hotspot has been associated with increased risk of MDS disease progression to acute myeloid leukemia (AML). However, the prognostic impact across all myeloid neoplasms inclusive of myeloproliferative neoplasms (MPN) and MDS/MPN overlap syndromes has not been established. Mutation information was collated from available datasets inclusive of unpublished clinical trial cohorts across patients with myeloid neoplasms (MDS, MPN, MDS/MPN, AML) and patients with solid malignancies and clonal hematopoiesis (CH). SF3B1 hotspot mutations were correlated with additional somatic mutations, disease type and other clinical parameters. Overall, 11,744 patients with myeloid neoplasms; MDS (n=4275), AML (n=3526), MDS/MPN (n=192), MPN (n=3751) and 24,146 patients with solid malignancies and CH were included in this analysis. SF3B1 mutations were present in 11.1% of patients; 21.3% MDS, 4.1% AML, 51% MDS/MPN and 3.7% MPN. In MDS, SF3B1 mutations were predominantly present in low risk MDS (23.8%) as compared with 4.1% in intermediate to high risk MDS. This contrasts with MPN where SF3B1 mutations were present at a higher frequency in more advanced MPN (5.5% in treatment-resistant ET, 8.8% in all MF cases and further augmented at 14% in JAK inhibitor resistant high-risk thrombocytopenic MF) as compared with earlier phase MPN (2.1% and 1.3% in ET and PV respectively). In MPN SF3B1-mutant cases, JAK-STAT signaling driver mutation frequency and distribution were in line with published data; 65.6% JAK2V617F-mutated, 18.8% CALR-mutated, 8.5% MPL-mutated and 7% triple negative. As previously described, SF3B1 K700E hotspot mutations were most prevalent (frequency 49.1%), followed by K666, H622 and R625 hotspot mutations at 20.6%, 7.6% and 6.1% respectively. K700E was enriched as expected in MDS cohorts and K666 hotspot mutations were enriched in AML (42%). Although less common in MDS (11.6 - 17.8%), the frequency of K666 mutation correlated with higher IPSS-M risk category in MDS (p=0.001; chi-squared test). In contrast to MDS, SF3B1 K666 was the dominant hotspot in MPN ranging 46-70% in frequency across subtypes from earlier to more advanced MPN such as MF (Fig 1A). SF3B1 K700E mutations were more often co-mutated with epigenetic mutations such as in DNMT3A, TET2, EZH2 and KMT2C genes (Fig 1B) whereas SF3B1 K666 mutations were significantly co-mutated with NPM1 and FLT3 in AML cases (odds ratio, OR, 25.6 and 4.2 respectively, p-value &amp;lt;0.0001) and JAK2V617F in MPN cases (OR 3.2, p&amp;lt;0.0001). SF3B1 K666 mutations also showed a trend towards significant co-occurrence with adverse prognostic mutations in AML; PHF6, PTPN11 and RUNX1. No differences were observed for SF3B1 hotspots for CALR or MPL-mutated MPN but numbers were too few to draw conclusions. In patients with SF3B1 mutations, 58% were male and K666 hotspot was more frequent in males (21% as compared with 11% in females, p&amp;lt;0.001, chi-squared test). There were no hotspot differences observed in age, ethnicity, bloods counts or karyotype where data was available for this analysis. In CH, SF3B1 mutations were detected in 0.5% with K700E (34.2%) and K666 (26.7%) frequencies equivalent (p=0.24). In summary, this large multi-cohort myeloid neoplasm analysis reveals myeloid disease-specific SF3B1 hotspot propensity. The K666 hotspot was frequent in MPN, particularly in persons with advanced disease where SF3B1 mutations are more prevalent than earlier phase MPN. We conclude that different SF3B1 hotspots are associated with distinct clinical phenotypes and in chronic myeloid malignancies; K666 SF3B1 mutation is associated with adverse clinical course. Additional studies to elucidate the distinct biological effects of different SF3B1 mutations are warranted.

Novel α-1,3-Glucosyltransferase Variants and Their Broad Clinical Polycystic Liver Disease Spectrum.

Protein-truncating variants in α-1,3-glucosyltransferase (ALG8) are a risk factor for a mild cystic kidney disease phenotype. The association between these variants and liver cysts is limited. We aim to identify pathogenic ALG8 variants in our cohort of autosomal dominant polycystic liver disease (ADPLD) individuals. In order to fine-map the phenotypical spectrum of pathogenic ALG8 variant carriers, we performed targeted ALG8 screening in 478 ADPLD singletons, and exome sequencing in 48 singletons and 4 patients from two large ADPLD families. Eight novel and one previously reported pathogenic variant in ALG8 were discovered in sixteen patients. The ALG8 clinical phenotype ranges from mild to severe polycystic liver disease, and from innumerable small to multiple large hepatic cysts. The presence of <5 renal cysts that do not affect renal function is common in this population. Three-dimensional homology modeling demonstrated that six variants cause a truncated ALG8 protein with abnormal functioning, and one variant is predicted to destabilize ALG8. For the seventh variant, immunostaining of the liver tissue showed a complete loss of ALG8 in the cystic cells. ALG8-associated ADPLD has a broad clinical spectrum, including the possibility of developing a small number of renal cysts. This broadens the ADPLD genotype-phenotype spectrum and narrows the gap between liver-specific ADPLD and kidney-specific ADPKD.

Baseline circulating tumor cell (CTC) count as a prognostic marker of overall survival (OS) in metastatic hormone sensitive prostate cancer (mHSPC): Results from SWOG S1216, a phase III randomized trial of androgen deprivation plus orteronel (cyp17 inhibitor) or bicalutamide.

5080 Background: Biomarkers are needed to predict clinical outcomes in mHSPC. We previously reported that baseline CTC counts in S1216 were prognostic of PSA response and disease progression ( ASCO 2020; CCR 2021). However, the trial’s primary overall survival (OS) endpoint was not yet mature at that time. Here we present the final results of S1216 using all available samples to assess the prognostic value of CTC counts for response, progression, OS, and treatment arm interactions. Methods: In S1216, peripheral blood was drawn with informed consent at registration (baseline) and at progression to metastatic castrate resistant prostate cancer (mCRPC). CTCs were enumerated on the FDA-cleared CellSearch platform (Menarini). CTC counts were evaluated for associations with 3 pre-specified trial endpoints: 7-month PSA (7mPSA) ≤ 0.2 ng/ml vs. 0.2–4.0 vs. &gt; 4.0 using a generalized logit model; and progression-free survival (PFS) and OS using Cox regression. Results: From 2014 to 2021, 503 evaluable samples were collected at baseline and 93 at progression. Baseline CTC count was ≥5 in 11.9% of samples, 1-4 in 19.3%, and 0 in 66.8%. Comparing men with 0 vs. ≥5 CTCs at baseline, those with 0 CTCs were significantly more likely to attain a complete PSA response and had significantly lower risk of a PFS event and death after adjusting for clinical covariates (disease burden, bone metastases, age, race, alkaline phosphatase, hemoglobin, PSA, treatment arm). These associations were not modified by treatment arm. Progression CTCs &lt;5 vs. ≥5 also were prognostic of OS (logrank p=0.001), consistent with prior findings in mCRPC. Same-patient CTC counts in matched baseline-progression pairs (n=61) were highly correlated (Spearman p&lt;0.001). Conclusions: CTC count at the start of treatment for mHSPC was highly prognostic of PSA response, PFS, and OS; associations that held in both treatment arms. Moreover, baseline CTC count strongly correlated with progression count, suggesting that mild vs. aggressive disease phenotypes may persist from mHSPC to mCRPC. This evidence from a large prospective phase 3 trial suggests that baseline CTC count is a valuable prognostic marker in men initiating therapy for mHSPC, discriminating those likely to experience favorable vs. unfavorable response and OS. [Table: see text]

Huntingtin polyglutamine expansions impair the transport of signalling and degradative cargoes.

Huntingtin scaffolds motor proteins and adaptors to vesicular cargoes. Through interactions with kinesin, dynein, and myosin-VI, huntingtin regulates the direction of transport along microtubules and switching between microtubules and actin filaments. Huntington's disease (HD) is caused by polyglutamine (polyQhtt) expansion of length >35Q at Huntington's N-terminus, with longer repeats leading to more severe neurodegeneration. Defects in transport of brain-derived neurotrophic factor (BDNF) and lysosomes have been reported in cells expressing polyQhtt. We track signalling BDNF vesicles and degradative lysosomes in induced neurons from isogenic human stem cell lines with repeat lengths of 18, 30, 45, 65, and 81Q to understand how transport of signalling and degradative cargoes are affected in HD. Preliminary data indicate that lysosomes have lower processivity and similar run lengths with pathological polyQhtt. Interestingly, the 45Q cells have lower processivity and run length compared to all other conditions, indicating divergent mechanisms might contribute to mild and severe disease phenotypes. Lysosomes are typically transported towards the soma. However, with polyQhtt we observe increased outward motility, suggesting huntingtin's ability to regulate transport direction is impaired. To examine how polyQ huntingtin alters the activity of kinesin and dynein, we use optical tweezers to measure the forces exerted on endocytosed BDNF-coated nanodiamonds in control compared to 81Q neurons. BDNF-coated nanodiamonds (∼100 nm) are readily endocytosed by neurons and enable reliable force measurements due to their high refractive index. In parallel, we developed methods to isolate BDNF-phagosomes from neurons and reconstitute their motility along microtubules. Together, live-cell imaging, optical trapping, and in vitro reconstitution reveal how HD mutations impact the transport of signalling and degradative cargoes by misregulating the recruitment and activity of kinesin and dynein.

Minimal Kidney Disease Phenotype in Shroom3 Heterozygous Null Mice.

Shroom family member 3 (SHROOM3) encodes an actin-associated protein that regulates epithelial morphology during development. Several genome-wide association studies (GWAS) have identified genetic variances primarily in the 5' region of SHROOM3, associated with chronic kidney disease (CKD) and poor transplant outcomes. These genetic variants are associated with alterations in Shroom3 expression. Characterize the phenotypic abnormalities associated with reduced Shroom3 expression in postnatal day 3-, 1-month and 3-month-old mice. The Shroom3 protein expression pattern was determined by immunofluorescence. We generated Shroom3 heterozygous null mice (Shroom3Gt/+) and performed comparative analyses with wild type littermates based on somatic and kidney growth, gross renal anatomy, renal histology, renal function at postnatal day 3, 1 month, and 3 months. The Shroom3 protein expression localized to the apical regions of medullary and cortical tubular epithelium in postnatal wild type kidneys. Co-immunofluorescence studies confirmed protein expression localized to the apical side of the tubular epithelium in proximal convoluted tubules, distal convoluted tubules, and collecting ducts. While Shroom3 heterozygous null mice exhibited reduced Shroom3 protein expression, no differences in somatic and kidney growth were observed when compared to wild type mice. Although, rare cases of unilateral hypoplasia of the right kidney were observed at postnatal 1 month in Shroom3 heterozygotes. Yet renal histological analysis did not reveal any overt abnormalities in overall kidney structure or in glomerular and tubular organization in Shroom3 heterozygous null mice when compared to wild type mice. Analysis of the apical-basolateral orientation of the tubule epithelium demonstrated alterations in the proximal convoluted tubules and modest disorganization in the distal convoluted tubules at 3 months in Shroom3 heterozygotes. Additionally, these modest abnormalities were not accompanied by tubular injury or physiological defects in renal and cardiovascular function. Taken together, our results describe a mild kidney disease phenotype in adult Shroom3 heterozygous null mice, suggesting that Shroom3 expression and function may be required for proper structure and maintenance of the various tubular epithelial parenchyma of the kidney.

Individuals heterozygous for ALG8 protein-truncating variants are at increased risk of a mild cystic kidney disease

ALG8 protein-truncating variants (PTVs) have previously been described in patients with polycystic liver disease and in some cases cystic kidney disease. Given a lack of well-controlled studies, we determined whether individuals heterozygous for ALG8 PTVs are at increased risk of cystic kidney disease in a large, unselected health system-based observational cohort linked to electronic health records in Pennsylvania (Geisinger-Regeneron DiscovEHR MyCode study). Out of 174,172 patients, 236 were identified with ALG8 PTVs. Using ICD-based outcomes, patients with these variants were significantly at increased risk of having any kidney/liver cyst diagnosis (Odds Ratio 2.42, 95% confidence interval: 1.53-3.85), cystic kidney disease (3.03, 1.26-7.31), and nephrolithiasis (1.89, 1.96-2.97). To confirm this finding, blinded radiology review of computed tomography and magnetic resonance imaging studies was completed in a matched cohort of 52 thirty-plus year old ALG8 PTV heterozygotes and related non-heterozygotes. ALG8 PTV heterozygotes were significantly more likely to have cystic kidney disease, defined as four or more kidney cysts (57.7% vs. 7.7%), or bilateral kidney cysts (69.2% vs. 15.4%), but not one or more liver cyst (11.5% vs. 7.7%). In publicly available UK Biobank data, ALG8 PTV heterozygotes were at significantly increased risk of ICD code N28 (other disorders of kidney/ureter) (3.85% vs. 1.33%). ALG8 PTVs were not associated with chronic kidney disease or kidney failure in the MyCode study or the UK Biobank data. Thus, PTVs in ALG8 result in increased risk of a mild cystic kidney disease phenotype.

Study of the expression of Cronos titin in TTN-truncation cardiomyopathy and heart development

Cronos is a recently discovered isoform of the giant protein titin driven by an alternative internal promoter. Cronos spans the half-A-band of a sarcomere and binds to myosin filaments, but its role in healthy or diseased hearts is largely unknown. Upregulation of Cronos has been suggested as a possible compensatory mechanism in titin-truncation cardiomyopathy, to help explain why truncations in titin's I-band region are less frequent and often cause a milder disease phenotype than truncations in the A-band region.

PHF6 Maintains Acute Myeloid Leukemia Via Regulating NF-Κappab Signaling Pathway

Acute myeloid leukemia (AML) is a major hematopoietic malignancy characterized by the uncontrolled expansion of the immature myeloid cells in the hematopoietic system. Current chemotherapy regimens remain ineffective as assessed by low remission and 5-year-survival rate. Many efforts have been dedicated to decipher the molecular events underlying AML transformation. PHF6 is a conserved epigenetic regulator and has been found to be frequently altered in hematologic malignancies. Previous studies demonstrated that PHF6 plays a suppressive role in T-ALL leukemogenesis. However, the functional role(s) of PHF6 in AML initiation and progression remains unknown. Here in this study, we analyzed the mRNA expression of PHF6 in blood cells from healthy donors and leukemia cells from AML patients, and found that the PHF6 expression was significantly increased in AML cells when compared with that of normal PMNs (www.Bloodspot.com) (p < 0.05). Significantly, the average survival time of AML patients with high PHF6 expression was much shorter than that of AML patients with low PHF6 expression (p = 0.022). Overexpressing of PHF6 (PHF6 OE) in Kasumi-1 or K562 leukemia cell lines showed increased growth of Kasumi-1 and K562 cells, decreased apoptosis of Kasumi-1 cells. Additionally, we knocked down (KD) PHF6 expression in AML cells and CD34+ cord blood cells, and found that PHF6 KD significantly decreased the growth of Kasumi-1 and promoted cell apoptosis, while had little effects on apoptosis of CD34+ cord blood cells. These results suggested that PHF6 is required for the growth of myeloid leukemia cells but is dispensable for normal blood cells. To further evaluate the functional role of Phf6 in leukemogenesis in vivo, we generated Phf6 KO+RUNX1-ETO9a (RE9a) and Phf6 KO+MLL-AF9 (MA9) AML mice. We found the survival time of Phf6 KO+RE9a mice was significantly longer than that of WT Phf6+RE9a mice. The Phf6 KO+RE9a mice showed much milder disease phenotypes than WT Phf6+RE9a mice, including lower counts of GFP+ leukemia cells in the PB and BM, higher body weights, lower spleen and liver weights, and lower degree of extramedullary infiltration in spleen, liver, lung and brain. Extreme limiting dilution transplantation assays demonstrated a marked decrease in leukemia stem cell (LSC) activity in Phf6 KO+RE9a cells when compared with Phf6 WT+RE9a cells. Consistent with RE9a-induced AML mouse model, PHF6 deficiency impaired the self-renewal of LSCs and delayed the progression of MA9-induced AML, supporting a general oncogenic role of Phf6 in sustaining myeloid leukemia. To investigate the underlying molecular mechanisms of Phf6 in regulating AML development, we performed RNAseq to analyze the transcriptome programing changes associated with Phf6 deficiency in isogenic Phf6 WT+RE9a or Phf6 KO+RE9aAML cells. Gene set enrichment analysis (GSEA) showed up-regulation of apoptosis and down-regulation of NF-κB-regulated gene expressions in Phf6 KO+RE9a cells, suggesting that Phf6 depletion might promote AML cell apoptosis by blocking the NF-κB signaling. Immunocytochemistry studies showed that PHF6 depletion partially inhibited the nuclear translocation of p50. Co-immunoprecipitation experiments revealed that PHF6 directly bound to p50 in myeloid leukemia cells, suggesting that PHF6 might activate NF-κB signaling pathways by binding with p50 and maintaining the nuclear translocation of p50. To confirm this, we treated PHF6 OE AML cells with BAY11-7082 (a selective NF-κB inhibitor), and found BAY11-7082 significantly inhibited the growth of PHF6 OE Kasumi-1 cells in vitro. In summary, we revealed that PHF6 promoted RE9a- or MA9-induced AML progression in mice by activating NF-κB signaling pathway, and promoting P50 nuclear translocation. Our study thus defined a unique role for Phf6 in regulating NF-κB signaling pathway in AMLs, and potentially can be used as a therapeutic target for treating myeloid leukemia patients.

Cost-Effectiveness of Exome Sequencing versus Targeted Gene Panels for Prenatal Diagnosis of Fetal Effusions and Non-Immune Hydrops Fetalis

Although exome sequencing has a greater overall diagnostic yield than targeted gene panels in the evaluation of nonimmune hydrops fetalis and fetal effusions, the cost-effectiveness of this approach is not known. This study aimed to evaluate the costs and outcomes of targeted gene panels vs exome sequencing for prenatally diagnosed nonimmune hydrops fetalis and fetal effusions when next-generation sequencing is pursued following nondiagnostic standard nonimmune hydrops fetalis evaluations, including karyotype or chromosomal microarray. A decision-analytical model was designed using TreeAge Pro to compare 10 genetic testing strategies, including a single test only (RASopathy, metabolic, or nonimmune hydrops fetalis-targeted gene panel or exome sequencing), sequential testing (RASopathy panel followed by nonimmune hydrops fetalis panel, metabolic panel followed by nonimmune hydrops fetalis panel, RASopathy panel followed by exome sequencing, metabolic panel followed by exome sequencing, and nonimmune hydrops fetalis panel followed by exome sequencing), and no additional genetic testing. Our theoretical cohort included cases with normal karyotype and/or microarray and excluded cases of alloimmunization and congenital viral infections. As nonimmune hydrops fetalis and fetal effusions can present throughout gestation, whereas pregnancy management options vary depending on gestational age, outcomes were calculated for 3 time intervals: 10 to 18, 18 to 22, and >22 weeks of gestation. The primary outcome was incremental cost per quality-adjusted life year. Additional outcomes included termination of pregnancy, stillbirth, neonatal death, and neonates born with mild, moderate, and severe or profound disease phenotypes. The cost-effectiveness threshold was $100,000 per quality-adjusted life year. Among women <18 weeks of gestation, exome sequencing alone was the dominant strategy associated with the lowest costs ($221 million) and the highest quality-adjusted life years (10,288). Strategies with exome sequencing alone or as a sequential test resulted in more terminations but fewer stillbirths, neonatal deaths (NNDs), and affected infants than strategies without exome sequencing. Among women between 18 and 22 weeks of gestation, exome sequencing alone was also associated with the lowest costs ($188 million) and the highest quality-adjusted life years (8734), and similar trends were observed in pregnancy outcomes. Among patients >22 weeks of gestations, when termination was not available, exome sequencing was associated with lower costs ($300 million) and the highest quality-adjusted life years (8492). Exome sequencing was cost-effective up to a cost per test of $50,451 at <18 weeks of gestation, $50,423 at 18 to 22 weeks of gestation, and $9530 at >22 weeks of gestation. Targeted genetic panels and exome sequencing were cost-effective strategies compared with no additional genetic testing. For cases of nonimmune hydrops fetalis and fetal effusions with nondiagnostic karyotype or microarray, next-generation sequencing was cost-effective compared with a strategy without additional genetic testing. For those that undergo next-generation sequencing, exome sequencing was the cost-effective strategy compared with all other testing strategies using targeted gene panels, leading to lower costs and fewer adverse perinatal outcomes. Exome sequencing was cost-effective in a setting without the option for pregnancy termination. These data supported the routine use of exome sequencing when next-generation sequencing is pursued for establishing a genetic diagnosis underlying otherwise unexplained nonimmune hydrops fetalis and fetal effusions.

THU092 - NAFLD patients scheduled for bariatric surgery present with a milder disease phenotype as compared to not morbidly obese NAFLD patients: analysis of a large real-world cohort

THU092 - NAFLD patients scheduled for bariatric surgery present with a milder disease phenotype as compared to not morbidly obese NAFLD patients: analysis of a large real-world cohort

Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy Family Members With a Pathogenic NOTCH3 Variant Can Have a Normal Brain Magnetic Resonance Imaging and Skin Biopsy Beyond Age 50 Years.

Background:To determine whether extremely mild small vessel disease (SVD) phenotypes can occur in NOTCH3 variant carriers from Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) pedigrees using clinical, genetic, neuroimaging, and skin biopsy findings.Methods:Individuals from CADASIL pedigrees fulfilling criteria for extremely mild NOTCH3-associated SVD (mSVDNOTCH3) were selected from the cross-sectional Dutch CADASIL cohort (n=200), enrolled between 2017 and 2020. Brain magnetic resonance imaging were quantitatively assessed for SVD imaging markers. Immunohistochemistry and electron microscopy was used to quantitatively assess and compare NOTCH3 ectodomain (NOTCH3ECD) aggregation and granular osmiophilic material deposits in the skin vasculature of mSVDNOTCH3 cases and symptomatic CADASIL patients.Results:Seven cases were identified that fulfilled the mSVDNOTCH3 criteria, with a mean age of 56.6 years (range, 50–72). All of these individuals harbored a NOTCH3 variant located in one of EGFr domains 7-34 and had a normal brain magnetic resonance imaging, except the oldest individual, aged 72, who had beginning confluence of WMH (Fazekas score 2) and 1 cerebral microbleed. mSVDNOTCH3 cases had very low levels of NOTCH3ECD aggregation in skin vasculature, which was significantly less than in symptomatic EGFr 7-34 CADASIL patients (P=0.01). Six mSVDNOTCH3 cases had absence of granular osmiophilic material deposits.Conclusions:Our findings demonstrate that extremely mild SVD phenotypes can occur in individuals from CADASIL pedigrees harboring NOTCH3 EGFr 7-34 variants with normal brain magnetic resonance imaging up to age 58 years. Our study has important implications for CADASIL diagnosis, disease prediction, and the counseling of individuals from EGFr 7-34 CADASIL pedigrees.

Profiles and Characteristics of Patients with Mild to Moderate COVID -19 Disease Phenotypes in a Teaching Hospital in Kano, Northern Nigeria

Background and Introduction: COVID-19 has affected almost 180 million people around the world, causing the death of about 5 million persons, as of November 16, 2021. The disease presents with a plethora of pulmonary and extrapulmonary symptoms of varying severity. After an exhaustive review of the literature, we found no data on the mild and moderate COVID-19 disease phenotypes in Northern Nigeria. Our objective is to describe the clinical characteristics of non-severe COVID -19 disease phenotypes in Kano State. Methods: This is a retrospective cohort study at the COVID-19 Isolation Center of Muhammad Buhari Specialist Hospital Kano, Nigeria. We included all patients admitted from May 2020 to December 2020. Patients’ medical records were assessed and evaluated to describe the clinical characteristics at presentation. We explored time to discharge between patients aged ≤ 50 years old versus those &gt;50. We applied the Kaplan-Meier product-limit estimator to generate cumulative probabilities of discharge over time and used the Log-rank test to determine differences between the two age groups. We applied Cox Proportional Hazards to identify predictors of time to discharge among the patients in the study. The study variables comprised of time of viral clearance and time to discharge as outcome variables, while main exposure variables included, age, sex, occupation, mode of exposure, presence of co-morbidity, and duration of hospitalization. Results: A total of 187 COVID-19 patients were reviewed. The commonest symptoms were fever, breathing difficulty, and dry cough. There was no recorded death. Contact with a confirmed COVID-19 positive person was the source of infection in 167(89.3%) of patients. We noted faster time to viral clearance in patients on lopinavir compared to those on chloroquine (Log-rank test p-value = 0.048). There were no significant differences in time to discharge between younger (&lt; 50 years) versus older patients (≥ 50 years) [24 days vs. 26 days respectively; Log-rank test p-value = 0.082]. Age, sex, and source of infection did not appear to be predictors of infection phenotype. Conclusion and Implications for Translation: The findings of this study have a bearing on the surveillance and diagnosis of COVID-19 in Nigeria. While the plethora of clinical features may not be limited to infection with the SARS-CoV-2 virus, healthcare practitioners should consider these symptom clusters in addition to cognate contact and travel history when confronted with a suspected COVID-19 infection. Copyright © 2022 Maiyaki et al. Published by Global Health and Education Projects, Inc. This is an open-access article distributed under the terms of the Creative Commons Attribution License CC BY 4.0.