Acute liver failure with hemolytic anemia in children with Wilson’s disease:Genotype-phenotype correlations?

BACKGROUND Wilson’s disease(WD)is a rare autosomal recessive inherited disorder of copper metabolism.Acute liver failure(ALF)and hemolytic anemia represent the most severe presentation of WD in children.No clear genotype-phenotype correlations exist in WD.Protein-truncating nonsense,frame-shift,or splice-site variants may be associated with more severe disease.In contrast,missense variants may be associated with late-onset,less severe disease,and more neurological manifestations.Recently,a gene variant(HSD17B13:TA,rs72613567)with a possible hepatic protective role against toxins was associated with a less severe hepatic phenotype in WD.AIM To analyze the possible genotype-phenotype correlations in children with WD presented with ALF and non-immune hemolytic anemia.METHODS The medical records of children with WD diagnosed and treated in our hospital from January 2006 to December 2020 were retrospectively analyzed.The clinical manifestations(ALF with non-immune hemolytic anemia or other less severe forms),laboratory parameters,copper metabolism,ATP7B variants,and the HSD17B13:TA(rs72613567)variant were reviewed to analyze the possible genotype-phenotype correlations.RESULTS We analyzed the data of 51 patients with WD,26 females(50.98%),with the mean age at the diagnosis of 12.36±3.74 years.ALF and Coombs-negative hemolytic anemia was present in 8 children(15.67%),all adolescent girls.The Kayser-Fleisher ring was present in 9 children(17.65%).The most frequent variants of the ATP7B gene were p.His1069Gln(c.3207A>G)in 38.24% of all alleles,p.Gly1341Asp(c.4021G>A)in 26.47%,p.Trp939Cys(c.2817G>T)in 9.80%,and p.Lys844Ter(c.2530A>T)in 4.90%.In ALF with hemolytic anemia,p.Trp939Cys(c.2817G>T)and p.Lys844Ter(c.2530A>T)variants were more frequent than in other less severe forms,in which p.His1069Gln(c.3207A>G)was more frequent.p.Gly1341Asp(c.4021G>A)has a similar frequency in all hepatic forms.For 33 of the patients,the HSD17B13 genotype was evaluated.The overall HSD17B13:TA allele frequency was 24.24%.Its frequency was higher in patients with less severe liver disease(26.92%)than those with ALF and hemolytic anemia(14.28%).CONCLUSION It remains challenging to prove a genotype-phenotype correlation in WD patients.In children with ALF and hemolytic anemia,the missense variants other than p.His1069Gln(c.3207A>G)and frame-shift variants were the most frequently present in homozygous status or compound heterozygous status with site splice variants.As genetic analysis is usually time-consuming and the results are late,the importance at the onset of the ALF is questionable.If variants proved to be associated with severe forms are found in the pre-symptomatic phase of the disease,this could be essential to predict a possible severe evolution.

Clinical features and genotype-phenotype correlation analysis in patients with ATL1 mutations:A literature reanalysis

Background:The hereditary spastic paraplegias(HSPs)are a group of clinically and genetically heterogeneous disorders.Approximately 10% of the autosomal dominant(AD)HSPs(ADHSPs)have the spastic paraplegia 3A(SPG3A)genotype which is caused by ATL1 gene mutations.Currently there are more than 60 reported ATL1 gene mutations and the genotype-phenotype correlation remains unclear.The study aims to investigate the genotypephenotype correlation in SPG3A patients.Methods:We performed a reanalysis of the clinical features and genotype-phenotype correlations in 51 reported studies exhibiting an ATL1 gene mutation.Results:Most HSPs-SPG3A patients exhibited an early age at onset(AAO)of<10 years old,and showed an autosomal dominant pure spastic paraplegia.We found that 14% of the HSPs-SPG3A patients presented complicated phenotypes,with distal atrophy being the most common complicated symptom.The AAO of each mutation group was not statistically significant(P>0.05).The mutational spectrum associated with ATL1 gene mutation is wide,and most mutations are missense mutations,but do not involve the functional motif of ATL1 gene encoded atlastin-1 protein.Conclusions:Our findings indicate that there is no clear genotype-phenotype correlation in HSPs-SPG3A patients.We also find that exons 4,7,8 and 12 are mutation hotspots in ATL1 gene.

Multifaceted superoxide dismutase 1 expression in amyotrophic lateral sclerosis patients:a rare occurrence?

Amyotrophic lateral sclerosis(ALS)is a neuromuscular condition resulting from the progressive degeneration of motor neurons in the cortex,brainstem,and spinal cord.While the typical clinical phenotype of ALS involves both upper and lower motor neurons,human and animal studies over the years have highlighted the potential spread to other motor and non-motor regions,expanding the phenotype of ALS.Although superoxide dismutase 1(SOD1)mutations represent a minority of ALS cases,the SOD1 gene remains a milestone in ALS research as it represents the first genetic target for personalized therapies.Despite numerous single case reports or case series exhibiting extramotor symptoms in patients with ALS mutations in SOD1(SOD1-ALS),no studies have comprehensively explored the full spectrum of extramotor neurological manifestations in this subpopulation.In this narrative review,we analyze and discuss the available literature on extrapyramidal and non-motor features during SOD1-ALS.The multifaceted expression of SOD1 could deepen our understanding of the pathogenic mechanisms,pointing towards a multidisciplinary approach for affected patients in light of new therapeutic strategies for SOD1-ALS.

The landscape of cognitive impairment in superoxide dismutase 1-amyotrophic lateral sclerosis

Although mutations in the superoxide dismutase 1 gene account for only a minority of total amyotrophic lateral sclerosis cases,the discovery of this gene has been crucial for amyotrophic lateral sclerosis research.Since the identification of superoxide dismutase 1 in 1993,the field of amyotrophic lateral sclerosis genetics has considerably widened,improving our understanding of the diverse pathogenic basis of amyotrophic lateral sclerosis.In this review,we focus on cognitive impairment in superoxide dismutase 1-amyotrophic lateral sclerosis patients.Literature has mostly reported that cognition remains intact in superoxide dismutase 1-amyotrophic lateral sclerosis patients,but recent reports highlight frontal lobe function frailty in patients carrying different superoxide dismutase 1-amyotrophic lateral sclerosis mutations.We thoroughly reviewed all the various mutations reported in the literature to contribute to a comprehensive database of superoxide dismutase 1-amyotrophic lateral sclerosis genotype-phenotype correlation.Such a resource could ultimately improve our mechanistic understanding of amyotrophic lateral sclerosis,enabling a more robust assessment of how the amyotrophic lateral sclerosis phenotype responds to different variants across genes,which is important for the therapeutic strategy targeting genetic mutations.Cognition in superoxide dismutase 1-amyotrophic lateral sclerosis deserves further longitudinal research since this peculiar frailty in patients with similar mutations can be conditioned by external factors,including environment and other unidentified agents including modifier genes.

Is new American Thyroid Association risk classification for hereditary medullary thyroid carcinoma applicable to Chinese patients? A single-center study

Objective: The American Thyroid Association (ATA) proposed a new risk classification for hereditary medullary thyroid carcinoma (MTC) in 2015. This study aimed to assess whether the new guidelines are suitable for the Chinese population, and reported our experience on prophylactic thyroidectomy. Methods: A total of 73 patients from 22 families were screened as rearranged during transfection (RET) mutation carriers from 2010 to 2016 in Cancer Hospital, Chinese Academy of Medical Science; the medical history for each patient was collected. Based on the initial treatment, we identified the risk factors for poor prognosis by univariate and multivariate logistic regression. Then, 4 RET mutation carriers were enrolled for prophylactic thyroidectomy, and their pathological data and follow-up outcomes were recorded. Results: In univariate and multivariate logistic regression analyses, age at initial surgery and risk classification were significant risk factors for stage III/IV hereditary MTC at initial diagnosis. The likelihood was increased by 11.6% per year of age at initial surgery [95% confidence interval (95% CI), 1.040-1.198; P=0.002). It was 7.888 times more likely to have III/IV stage disease for ATA highest risk patients, compared to ATA moderate risk individuals (95% CI, 1.607-38.717; P=0.003). Postoperative pathological results showed all 4 multiple endocrine neoplasia type 2A (MEN2A) patients had C-cell hyperplasia (CCH); multifocal malignancies were detected in 3 of them. All 4 patients were cured biochemically, and none developed permanent hypoparathyroidism. Conclusions: In Chinese individuals, hereditary MTC aggressiveness is in line with the new ATA risk classification. Germline RET gene mutation carriers should undergo prophylactic thyroidectomy according to basal serum calcitonin levels.

Genetic analyses in a cohort of 191 Chinese pulmonarv arterial hypertension patients

Objective Pulmonary arterial hypertension(PAH)is mainly characterized by pulmonary artery obstruction,which is diagnosed by a mean pulmonary artery pressure≥25 mm Hg at rest,and excluding other known causes of pulmonary hypertension.To identify genetic mutations and help make a precise diagnosis,we performed genetic testing in 191 probands with invasively confirmed PAH and tried to analyze the genotype-phenotype correlation.

SLC26A4 mutation testing for hearing loss associated with enlargement of the vestibular aqueduct

Pendred syndrome(PS) is characterized by autosomal recessive inheritance of goiter associated with a defect of iodide organification, hearing loss, enlargement of the vestibular aqueduct(EVA), and mutations of the SLC26A4 gene. However, not all EVA patients have PSor SLC26A4 mutations. Two mutant alleles of SLC26A4 are detected in 1/4 of North American or European EVA populations, one mutant allele is detected in another 1/4 of patient populations, and no mutations are detected in the other 1/2. The presence of two mutant alleles of SLC26A4 is associated with abnormal iodide organification, increased thyroid gland volume, increased severity of hearing loss, and bilateral EVA. The presence of a single mutant allele of SLC26A4 is associated with normal iodide organification, normal thyroid gland volume, less severe hearing loss and either bilateral or unilateral EVA. When other underlying correlations are accounted for, the presence of a cochlear malformation or the size of EVA does not have an effect on hearing thresholds. This is consistent with observations of an Slc26a4 mutant mouse model of EVA in which hearing loss is independent of endolymphatic hydrops or inner ear malformations. Segregation analyses of EVA in families suggest that the patients carrying one mutant allele of SLC26A4 have a second, undetected mutant allele of SLC26A4, and the probability of a sibling having EVA is consistent with its segregation as an autosomal recessive trait. Patients without any mutations are an etiologically heterogeneous group in which siblings have a lower probability of having EVA. SLC26A4 mutation testing can provide prognostic information to guide clinical surveillance and management, as well as the probability of EVA affecting a sibling.

Plaque Psoriasis: Understanding Risk Factors of This Inflammatory Skin Pathology

Covering the entire human body, the skin is considered to be one of the most important organs, since it is the first line of protection against chemical and biological external agents. Although the skin protects tissues and organs against external aggression, it can still be unbalanced by various skin diseases, such as psoriasis. This non-contagious inflammatory dermatosis is characterized by the occurrence of erythematous lesions of various sizes covered with whitish scales. This scaling of the skin is the result of a rapid renewal of the epidermis, occurring over five to seven days instead of 28 days. Psoriasis vulgaris, or plaque psoriasis, is the most common form of this disease and is therefore commonly referred to by the term “psoriasis”. This work is a review of the literature on plaque psoriasis, aiming at a better comprehension of the pathology at the histological level, but also to understand the genetic and environmental factors associated with this inflammatory dermatosis.

Double heterozygosity in sarcomere genes in a Chinese family with hypertrophic cardiomyopathy

Objective Familial hypertrophic cardiomyopathy(HCM)is a common autosome dominant cardiovascular disease,mainly caused by mutations in sarcomeric protein genes.Only about 5%of the patients carried double or compound heterozygosity,which might be related to earlier disease onset and more severe outcome.We aimed to identify the disease-causing mutation in a Chinese family with HCM and analyze the genotype-phenotype correlation.

Neurofibromatosis type Ⅰ caused by a splicing mutation in NF1 using targeted next generation sequencing

Objective Neurofibromatosis typeⅠ(NF1)is an autosomal dominant disorder which is caused by loss-of-function mutations in neurofibromin 1 gene(NF1).Clinically,NF1 mainly manifests several typical features,such as multiple neurofibromas and café-au-lait spots,as well as axillary freckling and Lisch nodules in iris.The aim of the current study is to identification a splicing mutation and genotype-phenotype correlation.

New era of cystic fibrosis:Full mutational analysis and personalized therapy

Despite its apparently simple genetics,cystic fibrosis(CF) is a rather complex genetic disease.A lot of variability in the steps of the path from the cystic fibrosis transmembrane conductance regulator(CFTR) gene to the clinical manifestations originates an uncertain genotype- phenotype relationship.A major determinant of this uncertainty is the incomplete knowledge of the CFTR mutated genotypes,due to the high number of CFTR mutations and to the higher number of their combinations in trans and in cis.Also the very limited knowledge of functional effects of CFTR mutated alleles severely impairs our diagnostic and prognostic ability.The final phenotypic modulation exerted by CFTR modifier genes and interactome further complicates the framework.The next generation sequencing approach is a rapid,lowcost and high-throughput tool that allows a near complete structural characterization of CFTR mutated genotypes,as well as of genotypes of several other genes cooperating to the final CF clinical manifestations.This powerful method perfectly complements the new personalized therapeutic approach for CF.Drugs active on specific CFTR mutational classes are already available for CF patients or are in phase 3 trials.A complete genetic characterization has been becoming crucial for a correct personalized therapy.However,the need of a functional classification of each CFTR mutation potently arises.Future big efforts towards an ever more detailed knowledge of both structural and functional CFTR defects,coupled to parallel personalized therapeutic interventions decisive for CF cure can be foreseen.

Genome-scale CRISPRi screening:A powerful tool in engineering microbiology

Deciphering gene function is fundamental to engineering of microbiology.The clustered regularly interspaced short palindromic repeats(CRISPR)system has been adapted for gene repression across a range of hosts,creating a versatile tool called CRISPR interference(CRISPRi)that enables genome-scale analysis of gene function.This approach has yielded significant advances in the design of genome-scale CRISPRi libraries,as well as in applica-tions of CRISPRi screening in medical and industrial microbiology.This review provides an overview of the recent progress made in pooled and arrayed CRISPRi screening in microorganisms and highlights representative studies that have employed this method.Additionally,the challenges associated with CRISPRi screening are discussed,and potential solutions for optimizing this strategy are proposed.

Application of next-generation sequencing to screen for pathogenic mutations in 123 unrelated Chinese patients with Marfan syndrome or a related disease

Marfan syndrome(MFS) is a systemic connective tissue disease principally affecting the ocular, skeletal and cardiovascular systems. This autosomal dominant disorder carries a prevalence of 1:3,000 to 1:5,000. This study aims to define the mutational spectrum of MFS related genes in Chinese patients and to establish genotype-phenotype correlations in MFS. Panel-based targeted next-generation sequencing was used to analyze the FBN1, TGFBR1 and TGFBR2 genes in 123 unrelated Chinese individuals with MFS or a related disease. Genotype-phenotype correlation analyses were performed in mutation-positive patients. The results showed that 97 cases/families(78.9%;97/123) harbor at least one(likely) pathogenic mutation, most of which were in FBN1;four patients had TGFBR1/2 mutations;and one patient harbored a SMAD3 mutation. Three patients had two FBN1 mutations, and all patients showed classical MFS phenotypes. Patients with a dominant negative-FBN1 mutation had a higher prevalence of ectopia lentis(EL). Patients carrying a haploinsufficiency-FBN1 mutation tended to have aortic dissection without EL. This study extends the spectrum of genetic backgrounds of MFS and enriches our knowledge of genotype-phenotype correlations.

Identification of a novel lethal fibrillin-1 gene mutation in a Chinese Marfan family and correlation of 3＇ fibrillin-1 gene mutations with phenotype

Background Mutations in the fibrillin-1 gene have been identified in patients with Marfan syndrome （MFS）. This study aimed to identify the molecular defects in the fibrillin-1 gene in a Chinese family with Marfan syndrome, accompanied by aortic aneu rysms/dissection. Methods Two patients and one non-carrier in the family underwent complete physical, ophthalmic, and cardiovascular examinations. Genomic DNA was extracted from leukocytes of venous blood of these individuals in the family as well as 50 healthy normal controls. Polymerase chain reaction amplification and direct sequencing of all 65 coding exons of fibrillin-1 gene were analyzed. Results We found a novel mutation （c.8547T〉G, p.Tyr2849X） in exon 65 of fibrillin-1 gene in a Chinese proband with Marfan syndrome, accompanied by aortic aneurysms/dissection. Sudden death at a young age of affected members was seen due to aortic aneurysms/dissection. By evaluating genotype-phenotype correlations of patients with mutations in the 3＇ end of fibrillin-1 gene （exons 64 and 65）, we also found that the presence of nonsense mutations occurring in exons 64 and 65 appeared to be an indicator of early-onset aortic risk and sudden death. Conclusions These results expand the mutation spectrum of fibrillin-1 gene and help in the study of the molecular pathogenesis of Marfan syndrome, indicating that mutations occurring in the 3＇ end of fibrillin-1 gene may play an independent functional role in the pathogenesis of Marfan syndrome.

Clinical and genetic characterization of a large cohort of patients with Wilson’s disease in China

Background: Wilson’s disease (WD) is an autosomal recessive disorder of copper metabolism caused by ATP7B (encoding a copper-transporting P-type ATPase) variants that shows various characteristics according to race and geographical region. This study was aimed to provide a comprehensive analysis of ATP7B variants in China and to investigate a plausible role of common variants in WD manifestations. Methods: A total of 1366 patients (1302 index patients and 64 siblings) clinically diagnosed with WD (Leipzig score ≥ 4) were recruited. They underwent ATP7B gene sequencing and information of age and symptoms at onset was collected. The genotype-phenotype correlation was assessed in the index patients who were examined with two pathogenic variants and onset with hepatic (n = 276) or neurologic (n = 665) symptoms. Results: We identified 294 potentially pathogenic ATP7B variants (112 truncating, 174 missense, 8 in-frame) in the 1302 index patients, including 116 novel variants. The most frequent variant was c.2333G>T (R778L, allele fre-quency: 28.96%), followed by c.2975C>T (P992L, 13.82%), c.2621C>T (A874V, 5.99%), c.2755C>G (R919G, 2.46%), and c.3646G>A (V1216M, 1.92%). In 1167 patients, both pathogentic variants were identified, of which 532 differ-ent variant combinations were found. By binary logistic regression analysis, the factor associated with neurological presentation was high age-at-onset, but not sex, protein-truncating variant (PTV), or the common missense variants (R778L, P992L, and A874V). In the neurological group, low age-at-onset was a factor associated with dystonia, gait abnormality, and salivation;high age-at-onset was a factor associated with tremor;and the sex, low age-at-onset and A874V were independent factors associated with dysarthria. In addition, PTV, R778L, and P992L were predominant in early-onset patients, whereas A874V was predominant in late-onset patients, and patients with R778L/A874V geno-type displayed a higher age-at-onset than patients with R778L/R778L or R778L/P992L genotype. Conclusions: Our work expanded the ATP7B variant spectrum and highlighted the differences among patients with WD in age-at-onset and ATP7B variants, which may provide some valuable insights into the diagnosis, counseling, and treatment of patients with WD.

Filaggrin Gene Mutation c.3321delA is Associated with Dry Phenotypes of Atopic Dermatitis in the Chinese Han Population

INTRODUCTION Atopic dermatitis （AD） is a common chronic inflammatory skin disorder that is characterized by dry skin and disturbed skin barrier functions. Mutations in the filaggrin （FLG） gene, the gene coding profilaggrin/filaggrin, have a great impact on the epidermal barrier function and are an important predisposing factor for AD. However, in both Europeans and Asians,

Clinical exome sequencing facilitates the understanding of genetic heterogeneity in Leber congenital amaurosis patients with variable phenotype in southern India

Background:Leber congenital amaurosis(LCA),primarily characterized by retinal degeneration is the most severe form of inherited retinal dystrophy(IRD)responsible for congenital blindness.The presence of phenotypic heterogeneity makes the diagnosis of LCA challenging,especially in the absence of pronounced disease pathognomonic,yet it can be well comprehended by employing molecular diagnosis.Therefore,the present study aimed to reveal the causative mutations in ten LCA patients with variable phenotypes using clinical exome sequencing(CES).Methods:CES was performed in ten unrelated LCA patients.Ophthalmic information and family history of all patients were obtained to make a meaningful interpretation.The clinical exome data was analyzed and prioritized using a bioinformatics pipeline to identify mutations,which was further validated by Sanger sequencing.Segregation analysis was also performed on available family members.Results:CES led to the identification of causative mutations in nine LCA patients.Seven patients harbored a mutation in six LCA candidate genes,including RPE65,LCA5(n=2),CRX,PRPH2,CEP290,and ALMS1,while two patients possess a mutation in IFT80 and RP1,known to cause other diseases.Three novel mutations in LCA5(c.1823del),CRX(c.848del)and CEP290(c.2483G>T)were identified.The current study reports for the first time,a mutation in PRPH2,CEP290,and ALMS1 from the Indian population.Additionally,we observed a novel association of LCA phenotype with IFT80 known to cause Jeune syndrome.Based on the genetic finding,the patient AS09,who harbored a mutation in the RP1 gene,was re-diagnosed with early-onset retinitis pigmentosa.Conclusion:In conclusion,the results underline the importance of CES in clinically diagnosed LCA patients with variable phenotypes.The correlation between mutations in candidate genes and clinical phenotypes,helps to refine the clinical diagnosis.However,molecular evaluation with a larger cohort of LCA patients is needed for better understanding of the mutational spectrum in southern India.

Identification of rare PTCH1 nonsense variant causing orofacial cleft in a Chinese family and an up-to-date genotype- phenotype analysis

The Patched 1(PTCH1)gene encodes a membrane receptor involved in the Hedge-hog(Hh)signaling pathway,an abnormal state of which may result in congenital defects or hu-man tumors.In this study,we conducted whole-exome sequencing on a three-generation Chinese family characterized with variable penetrance of orofacial clefts.A rare heterozygous variant in the PTCH1 gene(c.2833C>T p.R945X)was identified as a disease-associated mutation.Structural modeling revealed a truncation starting from the middle of the second extracellular domain of PTCH1 protein.This may damage its ligand recognition and sterol transportation abilities,thereby affecting the Hh signaling pathway.Biochemical assays indi-cated that the R945X protein had reduced stability compared to the wild-type in vitro.In addi-tion,we reviewed the locations and mutation types of PTCH1 variants in individuals with clefting phenotypes,and analyzed the associations between clefts and locations or types of variants within PTCH1.Our findings provide further evidence that PTCH1 variants result in or-ofacial clefts,and contributed to genetic counseling and clinical surveillance in this family.

Roles of Meiotic Defects in Pathogenesis of Primary Ovarian Insufficiency

A matured oocyte has experienced three critical division stages: (1) proliferation in early fetal stage, (2) meiotic arrest at diplotene of prophase I, and (3) meiotic resumption and extrusion of the first polar body. The abnormalities of these stages are associated closely with female reproduction problems including primary ovarian insufficiency (POI), the pathogenic mechanisms of which consist of insufficient initial follicle number, accelerated follicle loss, and arrest of follicle development. Recently, many meiotic associated genetic factors were identified to be mutated in POI patients and mouse models, revealing the association between meiosis and ovarian reserve. In this review, we provide an overview of the genetic factors involved in meiotic prophase I and their pathogenic mechanisms in POI.

Genetic diagnosis of neonatal-onset seizures

Many seizures in neonates are due to early-onset epilepsy,which is often difficult to diagnose,especially to explore the causes.Recently,the development of next-generation sequencing(NGS)has led to the discovery of a large number of genes involved in epilepsy.This may improve prompt detection of early-onset epilepsy in neonates.This study aimed at analyzing the genotype-phenotype correlations in neonates with seizures in a bid to improve the understanding of genetic diagnosis of early-onset epilepsy.Clinical features and prognosis of 15 children who underwent genetic testing having had unexplained seizures from February 2016 to May 2018 in Children’s Hospital of Chongqing Medical University were analyzed retrospectively.The salient findings were:poor response to stimulus and abnormal electroencephalogram(EEG)in the initial period were observed in the group with concomitant genetic abnormalities.Despite the recent progress in genetic technology,molecular diagnosis for neonatal-onset epilepsy can be challenging due to genetic and phenotypic heterogeneities.However,some genotypes are associated with specific clinical manifestations and EEG patterns.Therefore,in-depth understanding of genotype-phenotype correlations would be useful to clinicians managing neonates with early-onset seizures.