Impact of clonal hematopoiesis of indeterminate potential on hepatocellular carcinoma in individuals with steatotic liver disease.

BACKGROUND AND AIMS: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a global epidemic and is the most rapidly rising cause of HCC. Clonal hematopoiesis of indeterminate potential (CHIP) contributes to neoplastic and cardiometabolic disorders and is considered a harbinger of tissue inflammation. CHIP was recently associated with increased risk of liver disease. The aim of this study was to examine whether CHIP is associated with HCC development in patients with SLD. APPROACH AND RESULTS: We considered individuals with MASLD-HCC (n=208) and controls with (n =414) and without (n =259) advanced fibrosis who underwent whole exome sequencing. CHIP was diagnosed when ≥2 variant callers identified a known myeloid mutation with variant allele frequency ≥2%. CHIP was observed in 116 participants (13.1%), most frequently in DNMT3A, TET2, TP53 , and ASXL1 , and correlated with age ( p <0.0001) and advanced liver fibrosis (p=0.001). Higher aspartate aminotransferase levels predicted non- DNMT3A -CHIP, in particular with variant allele frequency ≥10% (OR: 1.14, 1.03 -1.28 and OR: 1.30, 1.12 -1.49, respectively, p <0.05). After adjustment for sex, diabetes, and a polygenic risk, a score of inherited MASLD predisposition CHIP was associated with cirrhosis (2.00, 1.30 -3.15, p =0.02), and with HCC even after further adjustment for cirrhosis (OR: 1.81, 1.11 -2.00, 1.30 -3.15, p =0.002). Despite the strong collinearity among aging and development of CHIP and HCC, non- DNTM3A -CHIP, and TET2 lesions remained associated with HCC after full correction for clinical/genetics covariates and age (OR: 2.45, 1.35 -4.53; OR: 4.8, 1.60 -17.0, p =0.02). CONCLUSIONS: We observed an independent association between CHIP, particularly related to non- DNTM3A and TET2 genetic lesions and MASLD-HCC.

Low MBOAT7 expression, a genetic risk for MASH, promotes a profibrotic pathway involving hepatocyte TAZ upregulation.

BACKGROUND AND AIMS: The common genetic variant rs641738 C>T is a risk factor for metabolic dysfunction-associated steatotic liver disease and metabolic dysfunction-associated steatohepatitis (MASH), including liver fibrosis, and is associated with decreased expression of the phospholipid-remodeling enzyme MBOAT7 (LPIAT1). However, whether restoring MBOAT7 expression in established metabolic dysfunction-associated steatotic liver disease dampens the progression to liver fibrosis and, importantly, the mechanism through which decreased MBOAT7 expression exacerbates MASH fibrosis remain unclear. APPROACH AND RESULTS: We first showed that hepatocyte MBOAT7 restoration in mice with diet-induced steatohepatitis slows the progression to liver fibrosis. Conversely, when hepatocyte-MBOAT7 was silenced in mice with established hepatosteatosis, liver fibrosis but not hepatosteatosis was exacerbated. Mechanistic studies revealed that hepatocyte-MBOAT7 restoration in MASH mice lowered hepatocyte-TAZ (WWTR1), which is known to promote MASH fibrosis. Conversely, hepatocyte-MBOAT7 silencing enhanced TAZ upregulation in MASH. Finally, we discovered that changes in hepatocyte phospholipids due to MBOAT7 loss-of-function promote a cholesterol trafficking pathway that upregulates TAZ and the TAZ-induced profibrotic factor Indian hedgehog (IHH). As evidence for relevance in humans, we found that the livers of individuals with MASH carrying the rs641738-T allele had higher hepatocyte nuclear TAZ, indicating higher TAZ activity and increased IHH mRNA. CONCLUSIONS: This study provides evidence for a novel mechanism linking MBOAT7-LoF to MASH fibrosis, adds new insight into an established genetic locus for MASH, and, given the druggability of hepatocyte TAZ for MASH fibrosis, suggests a personalized medicine approach for subjects at increased risk for MASH fibrosis due to inheritance of variants that lower MBOAT7.

Prevalence and Determinants of Liver Disease in Relatives of Italian Patients With Advanced MASLD.

BACKGROUND & AIMS: Metabolic dysfunction associated steatotic liver disease (MASLD) has a strong genetic component. The aim of this study was to examine noninvasively the prevalence of MASLD and of advanced fibrosis in relatives of patients with advanced MASLD and the risk factors for liver involvement, with a focus on the contribution of common genetic risk variants. METHODS: We prospectively enrolled 98 consecutive probands with advanced fibrosis and/or hepatocellular carcinoma caused by MASLD and 160 nontwin first-degree relatives noninvasively screened for MASLD and advanced fibrosis at 4 Italian centers. We evaluated common genetic determinants and polygenic risk scores of liver disease. RESULTS: Among relatives, prevalence of MASLD was 56.8% overall, whereas advanced fibrosis was observed in 14.4%. At multivariable analysis in relatives, MASLD was associated with body mass index (odds ratio [OR], 1.31 [1.18-1.46]) and tended to be associated with diabetes (OR, 5.21 [0.97-28.10]), alcohol intake (OR, 1.32 [0.98-1.78]), and with female sex (OR, 0.54 [0.23-1.15]), whereas advanced fibrosis was associated with diabetes (OR, 3.13 [1.16-8.45]) and nearly with body mass index (OR, 1.09 [1.00-1.19]). Despite that the PNPLA3 risk variant was enriched in probands (P = .003) and overtransmitted to relatives with MASLD (P = .045), evaluation of genetic risk variants and polygenic risk scores was not useful to guide noninvasive screening of advanced fibrosis in relatives. CONCLUSIONS: We confirmed that about 1 in 7 relatives of patients with advanced MASLD has advanced fibrosis, supporting clinical recommendations to perform family screening in this setting. Genetic risk variants contributed to liver disease within families but did not meaningfully improve fibrosis risk stratification.

The genetics of portal hypertension: Recent developments and the road ahead.

Portal hypertension (PH), defined as a pathological increase in the portal vein pressure, has different aetiologies and causes. Intrahepatic PH is mostly secondary to the presence of underlying liver disease leading to cirrhosis, characterized by parenchymal changes with deregulated accumulation of extracellular matrix and vascular abnormalities; liver sinusoidal endothelial cells and hepatic stellate cells are key players in PH progression, able to influence each other. However, PH may also develop independently of parenchymal damage, as occur in portosinusoidal vascular disorder (PSVD), a group of clinical and histological entities characterized by portal vasculature dysfunctions. In this particular group of disorders, the pathophysiology of PH is still poorly understood. In the last years, several genetic studies, based on genome-wide association studies or whole-exome sequencing analysis, have highlighted the importance of genetic heritability in PH pathogenesis, both in cirrhotic and non-cirrhotic cases. The common PNPLA3 p.I148M variant, one of the main determinants of the susceptibility to steatotic liver disease, has also been associated with decompensation in patients with PH. Genetic variations at loci influencing coagulation, mainly the ABO locus, may directly contribute to the pathogenesis of PH. Rare genetic variants have been associated with familiar cases of progressive PSVD. In this review, we summarize the recent knowledges on genetic variants predisposing to PH development, contributing to better understand the role of genetic factors in PH pathogenesis.

Clinical exome sequencing for diagnosing severe cryptogenic liver disease in adults: A case series.

Liver diseases remain unexplained in up to 30% of adult patients; genetic analysis could help establish the correct diagnosis. In six adult patients with cryptogenic liver disease, we performed whole-exome sequencing (WES) and evaluated the individual predisposition to progressive fatty liver disease by polygenic risk scores (PRS). In one patient, WES was allowed to diagnose the Hermansky-Pudlak syndrome. In the other two patients, genetic variants in LDLRAP1/MSH6 and ALDOB genes were identified, contributing to explaining the clinical presentation and disease pathogenesis (50% diagnostic uptake). In the other three patients, rare variants with a high likelihood of disrupting protein function in APOB, ATP7B, ABCB4 and ATP8B1 were identified. One patient who developed hepatocellular carcinoma during the follow-up had a high PRS value. The study supports the role of WES, combined with risk stratification by PRS and accurate clinical assessment in improving the diagnosis and informed management in patients with cryptogenic liver disease, a positive family history or severe fatty liver not fully accounted for by environmental triggers.

Prenatal ultrasound findings associated with PIGW variants: One more piece in the FRYNS syndrome puzzle? PIGW-related prenatal findings.

OBJECTIVE: We describe the prenatal ultrasound findings and autopsy of three fetuses with multiple congenital anomalies (MCA) whose diagnostic workup suggested the same genetic etiology. We conducted a literature review to corroborate the molecular results and find evidence that the identified variants are responsible for the phenotype seen. METHODS: Trio-based Exome Sequencing (ES) analysis was performed on chorionic villus samples. We reviewed available reports dealing with prenatal manifestations of genes involved in the Glycosylphosphatidylinositols (GPI) biosynthesis defects (GPIBDs). RESULTS: Prenatal findings shared by all the three pregnancies included facial dysmorphisms, brain malformations of the posterior fossa, skeletal and genitourinary anomalies. ES analysis identified homozygous variants of uncertain significance in PIGW in the three fetuses. Prenatal findings of the three pregnancies overlapped with those previously described for PIGW variants and with those associated with PIGN, PIGV and PIGA variants. CONCLUSION: Based on the phenotypic overlap between the prenatal findings in our three cases and other cases with pathogenic variants in other genes involved in GPIBDs, we speculate that the variants identified in the three fetuses are likely causal of their phenotype and that the PIGWclinical spectrum might extend to MCA, mainly involving brain, skeletal and genitourinary systems. Moreover, we suggest that also PIGW could be involved in Fryns/Fryns-like phenotypes.

Trends and risk factors of SARS-CoV-2 infection in asymptomatic blood donors.

BACKGROUND: A large proportion of SARS-CoV-2-infected individuals does not develop severe symptoms. Serological tests help in evaluating the spread of infection and disease immunization. The aim of this study was to prospectively examine the trends and risk factors of SARS-CoV-2 infection in blood donors. STUDY DESIGN AND METHODS: We screened 8798 asymptomatic donors presenting in Milan from July 2020 to February 2021 (10,680 presentations) before the vaccination campaign for anti-nucleoprotein (NP) antibodies, and for anti-spike receptor-binding domain (RBD) antibodies and nasopharyngeal swab PCR in those who tested positive. RESULTS: The prevalence of anti-NP+/RBD+ tests increased progressively with time up to ~15% (p < .0001), preceded by a peak of PCR+ tests. Anti-RBD titers were higher in anti-NP IgG+/IgM+ than in IgG+/IgM- individuals and in those with a history of infection (p < .0001); of these 197/630 (31.2%) displayed high titers (>80 AU/ml). Anti-RBD titers declined during follow-up, depending on baseline titers (p < .0001) and time (p = .025). Risk factors for seroconversion were a later presentation date and non-O ABO blood group (p < .001). A positive PCR was detected in 0.7% of participants in the absence of SARS-CoV-2 viremia. CONCLUSIONS: During the second wave of SARS-CoV-2 infection in Northern Italy, we detected an increase in seroprevalence in healthy blood donors from ~4% to ~15%, with a trend paralleling that observed in the general population. Seroconversion was more frequent in carriers of non-O blood groups. The persistence of anti-RBD antibodies was short-lived.

Incidence of chromosomal abnormalities in fetuses with first trimester ultrasound anomalies and a low-risk cell-free DNA test for common trisomies.

OBJECTIVE: To examine the incidence and type of chromosomal abnormalities in fetuses with first trimester ultrasound anomalies and a low-risk cfDNA test for common trisomies. METHODS: In 486 singleton pregnancies undergoing invasive testing after combined screening, a detailed first trimester ultrasound assessment was carried out and a maternal blood sample was sent for cfDNA analysis. Ultrasound and cfDNA data were analyzed in relation to fetal karyotype. RESULTS: Invasive testing demonstrated a chromosomal abnormality in 157 (32.3%) of 486 fetuses. In 348 cases with a low-risk cfDNA test for common trisomies, NT ≥ 3.5 mm and/or a major structural defect were observed in 92 (26.4%) fetuses. A chromosomal abnormality was found in 17 (18.5%; 95%CI 10.55-26.41) of these pregnancies, including 1 (1.1%) case of trisomy 21 and 16 (17.4%) fetuses with abnormalities different from common trisomies. The respective incidence in the 256 cases with a low-risk cfDNA test result and no ultrasound anomalies was 2.3% (95% CI 0.49-4.20; n = 6). CONCLUSIONS: In fetuses with first trimester ultrasound anomalies and a low-risk cfDNA result for trisomy 21, 18 and 13, diagnostic testing should be offered with the main objective to detect chromosomal abnormalities beyond common trisomies.

Is cutis verticis Gyrata-Intellectual Disability syndrome an underdiagnosed condition? A case report and review of 62 cases.

Cutis Verticis Gyrata-Intellectual Disability (CVG-ID) syndrome is a rare neurocutaneous syndrome characterized by intellectual disability and scalp folds and furrows that are typically absent at birth and are first noticed after puberty. First reported in 1893, the syndrome was mainly identified in subjects living in psychiatric institutions, where it was found to have a prevalence of up to 11.4%. Most patients were reported in the literature during the first half of the 20th century. CVG-ID is now a less reported and possibly under-recognized syndrome. Here, we report a patient with CVG-ID that was diagnosed using the novel approach of magnetic resonance imaging and we conduct a systematic review of all patients reported in the last 60 years, discussing the core clinical features of this syndrome. © 2016 Wiley Periodicals, Inc.

2q33.1q34 Deletion in a Girl with Brain Anomalies and Anorectal Malformation.

2q33 deletions are considered to constitute a distinct clinical entity (Glass syndrome or 2q33 microdeletion syndrome) with a characteristic phenotype. Most patients have moderate to severe developmental delay, speech delay, a particular behavioural phenotype, feeding problems, growth restriction, a typical facial appearance, thin and sparse hair, tooth abnormalities, and skeletal anomalies. Here, we report on a patient with a 2q33.1q34 deletion spanning 8.3 Mb of genomic DNA. Although her clinical features are very reminiscent of the 2q33 microdeletion syndrome, she also presented with brain and anorectal malformations. Based on the present and published patients with 2q33 deletions, we suggest that the critical region for the Glass syndrome may be larger than initially proposed. Moreover, we suggest that brain abnormalities might be an additional feature of the 2q33 microdeletion syndrome, but that anorectal malformation is likely not a key marker.

The p.Phe174Ser mutation is associated with mild forms of Smith Lemli Opitz Syndrome.

BACKGROUND: Smith Lemli Opitz syndrome (SLOS; OMIM #270400) is an autosomal recessive metabolic disorder caused by mutations in the DHCR7 gene. SLOS is characterized by a plethora of abnormalities involving mainly the brain and the genitalia but also the cardiac, skeletal and gastroenteric system, typical dysmorphic facial features, and variable degrees of developmental delay and intellectual disability (ID). SLOS has a broad phenotypic spectrum, ranging from multiple congenital malformation syndrome, to mild developmental delay and minor malformations. A large number of mutations have been described in the DHCR7 gene, with few common mutations accounting for the majority of mutated alleles found in patients and a large number of very rare or even private variants. Due to the wide variety of clinical presentations, diagnosis can be difficult, especially in the milder forms of the disorder. Furthermore, establishing a molecular diagnosis can be complicated by finding variants of unknown clinical significance in such cases. CASE PRESENTATION: We report a case of SLOS at the mild end of the clinical spectrum, presenting with bilateral pelvis ectasia, mild dysmorphic features and mild intellectual disability. The case is compound heterozygous for a known pathogenic mutation (c.724C > T, p.Arg242Cys) and a mutation that has only been reported once in a Portuguese patient (c.521 T > C, p.Phe174Ser) whose pathogenicity has not been yet assessed. We compared the two patients carrying the p.Phe174Ser variant and concluded that this variant is associated with mild forms of SLOS. CONCLUSION: We report a patient with a mild case of SLOS, highlighting the importance of recognizing subtle anomalies of the genitourinary system, associated with mild dysmorphic features and mild intellectual disability in establishing the diagnosis of mild forms of SLOS. With this report, we confirm the pathogenicity of the p.Phe174Ser variant and we also provide evidence of its association with mild forms of SLOS. This finding further facilitates the establishment of a genotype-phenotype correlation for SLOS. This helps in counselling for this disorder and in predicting therapeutic responses.

Interstitial 6q25 microdeletion syndrome: ARID1B is the key gene.

Interstitial deletions of the long arm of chromosome 6 are rare. Clinically, these deletions are considered to be part of a unique microdeletion syndrome associated with intellectual disability and speech impairment, typical dysmorphic features, structural anomalies of the brain, microcephaly, and non-specific multiple organ anomalies. The critical region for the interstitial 6q microdeletion phenotype was mapped to 6q24-6q25, particularly the 6q25.3 region containing the genes ARID1B and ZDHHC14. It has been hypothesized that haploinsufficiency of these genes impairs normal development of the brain and is responsible for the phenotype. This case report describes a girl presenting with typical features of 6q microdeletion syndrome, including global developmental delay, speech impairment, distinct dysmorphic features, dysgenesis of the corpus callosum, common limb anomalies, and hearing loss. Chromosome analysis by array-CGH revealed a small interstitial 6q deletion spanning approximately 1.1 Mb of DNA and containing only one coding gene, ARID1B. We suggest that ARID1B is the key gene behind 6q microdeletion syndrome, and we discuss its possible role in the phenotypic manifestations.

Molecular cytogenetic characterization of a 2q35-q37 duplication and a 4q35.1-q35.2 deletion in two cousins: a genotype-phenotype analysis.

The 2q3 duplication and 4q3 deletion are two distinct conditions with variable phenotypes including developmental delay, intellectual disability, Pierre Robin sequence (PRS), and cardiovascular, craniofacial, digital and skeletal anomalies. We describe two cousins, a 37-year-old man (Patient 1) and a 17-year-old girl (Patient 2), with a derivative chromosome leading to a 4q35 deletion-2q35q37 duplication. Conventional karyotype showed in both patients the same rearrangement derived from unbalanced segregation of a parental reciprocal translocation involving the long arms of chromosome 2 and 4. Patient 1's father and Patient 2's mother were identified as the carriers of a balanced translocation t(2;4)(q35;q35). Array-CGH analysis, performed to characterize the rearrangement, documented in both patients the presence of a 26 Mb duplication of the 2q35-q37.3 region of chromosome 2 and a 6.3 Mb deletion of the 4q35.1-q35.2 region of chromosome 4. Both patients showed intellectual disability, minor facial, and digital anomalies, hearing, ocular, and genitourinary abnormalities. The comparison of their features with those of published cases of 2q3 duplication and 4q3 deletion allowed us to further delineate the genotype-phenotype correlation as well as the combined effect of partial 2q duplication and 4q deletion syndromes in adulthood.

Modulation of gamma globin genes expression by histone deacetylase inhibitors: an in vitro study.

Induction of fetal haemoglobin (HbF) is a promising therapeutic approach for the treatment of ß-thalassaemia and sickle cell disease (SCD). Several pharmacological agents, such as hydroxycarbamide (HC) and butyrates, have been shown to induce the γ-globin genes (HBG1, HBG2). However, their therapeutic use is limited due to weak efficacy and an inhibitory effect on erythroid differentiation. Thus, more effective agents are needed. The histone deacetylase (HDAC) inhibitors are potential therapeutic haemoglobin (Hb) inducers able to modulate gene expression through pleiotropic mechanisms. We investigated the effects of a HDAC inhibitor, Givinostat (GVS), on erythropoiesis and haemoglobin synthesis and compared it with sodium butyrate and HC. We used an in vitro erythropoiesis model derived from peripheral CD34⁺ cells of healthy volunteers and SCD donors. GVS effects on erythroid proliferation and differentiation and on Hb synthesis were investigated. We found that GVS at high concentrations delayed erythroid differentiation with no specific effect on HBG1/2 transcription. At a low concentration (1 nmol/l), GVS induced Hb production with no effects on cells proliferation and differentiation. The efficacy of GVS 1 mol/l in Hb induction in vitro was comparable to that of HC and butyrate. Our results support the evaluation of GVS as a new candidate molecule for the treatment of the haemoglobinophathies due to its positive effects on haemoglobin production at low and non-toxic concentrations.

Thalassemic erythrocytes release microparticles loaded with hemichromes by redox activation of p72Syk kinase.

High counts of circulating microparticles, originated from the membrane of abnormal erythrocytes, have been associated with increased thrombotic risk in hemolytic disorders. Our studies indicate that in thalassemia intermedia patients the number of circulating microparticles correlates with the capability of the thalassemic erythrocytes to release microparticles. The microparticles are characteristically loaded with hemichromes formed by denatured α-chains. This finding was substantiated by the positive correlation observed in thalassemia intermedia patients between the amount of hemichromes measured in erythrocytes, their capability to release microparticles and the levels of plasma hemichromes. We observed that hemichromes, following their binding to the cytoplasmic domain of band 3, induce the formation of disulfide band 3 dimers that are subsequently phosphorylated by p72Syk kinase. Phosphorylation of oxidized band 3 appears to be relevant for the formation of large hemichromes/band 3 clusters that, in turn, induce local membrane instability and the release of microparticles. Proteomic analysis of microparticles released from thalassemia intermedia erythrocytes indicated that, besides hemichromes and clustered band 3, the microparticles contain a characteristic set of proteins that includes catalase, heat shock protein 70, peroxiredoxin 2 and carbonic anhydrase. High amounts of immunoglobulins and C3 have also been found to be associated with microparticles, accounting for their intense phagocytosis. The effect of p72Syk kinase inhibitors on the release of microparticles from thalassemia intermedia erythrocytes may indicate new perspectives for controlling the release of circulating microparticles in hemolytic anemias.

Predictors of controlled attenuation parameter in metabolic dysfunction.

BACKGROUND & AIMS: Hepatic fat content can be non-invasively estimated by controlled attenuation parameter (CAP) during transient elastography. The aim of this study was to examine the determinants and predictors of CAP values in individuals with metabolic dysfunction. METHODS: We enrolled 1230 consecutive apparently healthy individuals (Liver-Bible-2022 cohort) with ≥3 metabolic dysfunction features. CAP was measured by Fibroscan. CAP determinants and predictors were identified using backward stepwise analysis and introduced in generalized linear models. RESULTS: Participants were predominantly males (82.9%), mean age was 53.8 ± 6.4 years, 600 (48.8%) had steatosis (CAP ≥ 275 dB/m), and 27 had liver stiffness measurement (LSM) ≥ 8 kPa. CAP values correlated with LSM (p < 10-22). In multivariable analysis, fasting insulin and abdominal circumference (AC) were the main determinants of CAP (p < 10-6), together with body mass index (BMI; p < 10-4), age, diabetes, triglycerides, ferritin, and lower HDL and thyroid stimulating hormone (TSH; p < 0.05 for all). In a subset of 592 participants with thyroid hormone measurement, we found an association between higher free triiodothyronine levels, correlating with lower TSH, and CAP values, independent of TSH and of levothyroxine treatment (p = 0.0025). A clinical CAP score based on age, BMI, AC, HbA1c, ALT, and HDL predicted CAP ≥ 275 dB/m with moderate accuracy (AUROC = 0.73), which was better than that of the Fatty Liver Index and of ALT (AUROC = 0.70/0.61, respectively) and validated it in multiple cohorts. CONCLUSION: Abdominal adiposity and insulin resistance severity were the main determinants of CAP in individuals with metabolic dysfunction and may improve steatotic liver disease risk stratification. CAP values were modulated by the hypophysis-thyroid axis.

Stratified analyses refine association between TLR7 rare variants and severe COVID-19.

Despite extensive global research into genetic predisposition for severe COVID-19, knowledge on the role of rare host genetic variants and their relation to other risk factors remains limited. Here, 52 genes with prior etiological evidence were sequenced in 1,772 severe COVID-19 cases and 5,347 population-based controls from Spain/Italy. Rare deleterious TLR7 variants were present in 2.4% of young (<60 years) cases with no reported clinical risk factors (n=378), compared to 0.24% of controls (odds ratio (OR)=12.3, p=1.27x10-10). Incorporation of the results of either functional assays or protein modeling led to a pronounced increase in effect size (ORmax=46.5, p=1.74x10-15). Association signals for X-chromosomal TLR7 were also detected in the female-only subgroup, suggesting the existence of additional mechanisms beyond X-linked recessive inheritance in males. Additionally, supporting evidence was generated for a contribution to severe COVID-19 of the previously implicated genes IFNAR2, IFIH1 and TBK1. Our results refine the genetic contribution of rare TLR7 variants to severe COVID-19, and strengthen evidence for the etiological relevance of genes in the interferon signaling pathway.