New genetic causes for complex hereditary spastic paraplegia

Clinical and molecular assessment of a spastic ataxia 4 (SPAX4) patient with a novel variant in the MTPAP gene, and a systematic review

Spastic ataxia (SPAX) is a heterogeneous neurodegenerative disorder characterized by the simultaneous occurrence of spastic paraplegia and cerebellar ataxia, making the diagnosis and classification challenging. Genetically, SPAX is categorized into subtypes SPAX1-10. Mutations in the MTPAP gene lead to SPAX4 and some other neurological diseases. This gene encodes an enzyme with a key role in polyadenylation of mitochondrial mRNAs. Here, during whole-exome sequencing of an Iranian HSP cohort, we identified the first Iranian SPAX4 case, and fifth globally with a novel MTPAP variant. We also performed a systematic review based on the PRISMA 2020 guidelines to catalog all known MTPAP variants and assess the clinical and genetic profiles of all identified cases. A novel variant, c.1072C > T in the MTPAP gene was identified and confirmed within the family using Sanger sequencing. The systematic review in four major databases for articles on MTPAP variants identified 12 MTPAP variants linked to various phenotypes. By comparing the obtained results, clinical and genetic heterogeneity was evident in the MTPAP-related disorders. Our findings significantly broaden the clinical and molecular landscape of MTPAP-related variants, extending beyond the confines of SPAX4.Due to the rarity of these diseases, considerable knowledge gaps persist regarding their underlying mechanisms and the implicated gene. Consequently, our research endeavors may facilitate the elucidation of pertinent biological pathways and the development of potential therapies.

A decade of whole-exome sequencing in Brazilian Neurology: from past insights to future perspectives

Over the last decade, whole-exome sequencing (WES) has become a standard diagnostic tool, significantly transforming the landscape of clinical genetics and playing a pivotal role in the diagnosis of neurogenetic diseases. This revolutionary shift has left a lasting impact on the field of neurology in Brazil. The current review article examines key developments and milestones achieved in Brazil through the application of WES in neurology and discusses forthcoming challenges and essential steps to advance molecular diagnosis. Several studies report the use of WES to diagnose genetic disorders with neurological manifestations in Brazil, underscoring the growing importance of molecular diagnosis in neurogenetics. These studies often provide detailed phenotypic analyses and clinical descriptions, offering valuable insights into the genetic underpinnings of several neurological conditions. Many reports highlight the use of WES in the investigation of complex neurological conditions in Brazil, such as neurodevelopmental disorders, hereditary spastic paraplegia, movement disorders, and ataxia. The discovery of new genes implicated in monogenic diseases with neurological manifestations through WES was a significant breakthrough. Despite these advances, the availability of large cohort studies on rare diseases in Brazil remains limited, hindering the ability to generalize findings and explore the full spectrum of genetic diversity. However, a few larger cohort studies have substantially contributed to our understanding of rare diseases and specific neurological disorders.While WES has limitations and may eventually be supplanted by more advanced diagnostic tools, it left a permanent mark on the neurology field in Brazil. The field of neurogenetics is set to become increasingly important in the future.

Case report of a family with hereditary inclusion body myopathy with VCP gene variant and literature review

Background

Missense VCP gene variants lead to a disruption in protein homeostasis causing a spectrum of progressive degenerative diseases. Myopathy is the most frequent manifestation characterized by slowly progressing weakness of proximal and distal limb muscles. We present a family with myopathy due to c.277C > T variant in VCP gene.

Case presentation

The patient's phenotype includes symmetrical muscle wasting and weakness in the proximal parts of the limbs and axial muscles, a wide based gait, lordotic posture, positive Gowers' sign, mild calf enlargement, impaired mobility, elevated CK, and myopathy in proximal limb muscles. Whole body MRI revealed fatty replacement, predominantly affecting right vastus intermedius and medialis, gastrocnemius and soleus in calf, abdomen wall and lumbar muscles. Next-generation sequencing analysis revealed a pathogenic heterozygous variant c.277C > T (p.(Arg93Cys)) in exon 3 of the VCP gene. Segregation analysis showed that the detected variant is inherited from the affected father who developed symptoms at 60.

Conclusion

The patients described experienced muscle wasting and weakness in the proximal and distal parts of the limbs which is a common finding in VCP related disease. Nevertheless, the patient has distinguishing features, such as high CK levels, early onset of the disease, and rapid mobility decline.

Expanding phenotype heterogeneity of NARS2 by presenting subdural hematoma and parenchymal hemorrhage

BACKGROUND

NARS2 encodes mitochondrial Asparaginyl-tRNA Synthetase 2, which catalyzes the aminoacylation of tRNA-Asn in the mitochondria. To date, 24 variants have been reported in NARS2 gene in 35 patients. The phenotypic variability of NARS2-associated disorder is broad, ranging from neurodevelopmental disorders to hearing loss. In this study, we report some novel imaging findings in an Iranian patient suffering from epileptic encephalopathy, caused by a previously reported variant, c.500A > G; p.(His167Arg), in NARS2.

METHODS

The spectrum of clinical manifestations of two Iranian patients was investigated and genetic analysis was performed by Whole-exome sequencing (WES). Additionally, we also reviewed the literature and summarized the phenotypes of previously reported patients with variants in the NARS2 gene.

RESULTS

Here, we present the phenotypic and genetic features of 2 unrelated Iranian infants presented with neurodevelopmental delay, seizures, hearing impairment, feeding problems, elevated serum lactate levels in addition to subdural hematoma and cerebral parenchymal hemorrhage in the brain magnetic resonance imaging (MRI) of one of the patients. Genetic analysis revealed a biallelic missense variant in NARS2: c.500A > G; p.(His167Arg). We described the subdural hematoma and cerebral parenchymal hemorrhage of the brain for the first time.

CONCLUSIONS

Our study provides new clinical findings, subdural hematoma, and parenchymal hemorrhage, in NARS2-related disorders. Our findings along with previous studies provide more evidence of the clinical presentation of the disease caused by pathogenic variants in NARS2. Expanding the clinical spectrum increases the diagnostic rate of molecular testing and improves the quality of counseling for at-risk couples.

Role of Mutations of Mitochondrial Aminoacyl-tRNA Synthetases Genes on Epileptogenesis

Mitochondria are the structures in cells that are responsible for producing energy. They contain a specific translation unit for synthesizing mitochondria-encoded respiratory chain components: the mitochondrial DNA (mt DNA). Recently, a growing number of syndromes associated with the dysfunction of mt DNA translation have been reported. However, the functions of these diseases still need to be precise and thus attract much attention. Mitochondrial tRNAs (mt tRNAs) are encoded by mt DNA; they are the primary cause of mitochondrial dysfunction and are associated with a wide range of pathologies. Previous research has shown the role of mt tRNAs in the epileptic mechanism. This review will focus on the function of mt tRNA and the role of mitochondrial aminoacyl-tRNA synthetase (mt aaRS) in order to summarize some common relevant mutant genes of mt aaRS that cause epilepsy and the specific symptoms of the disease they cause.

Power of NGS-based tests in HSP diagnosis: analysis of massively parallel sequencing in clinical practice

Hereditary spastic paraplegia (HSP) refers to a group of heterogeneous neurological disorders mainly characterized by corticospinal degeneration (pure forms), but sometimes associated with additional neurological and extrapyramidal features (complex HSP). The advent of next-generation sequencing (NGS) has led to huge improvements in knowledge of HSP genetics and made it possible to clarify the genetic etiology of hundreds of "cold cases," accelerating the process of reaching a molecular diagnosis. The different NGS-based strategies currently employed as first-tier approaches most commonly involve the use of targeted resequencing panels and exome sequencing, whereas genome sequencing remains a second-tier approach because of its high costs. The question of which approach is the best is still widely debated, and many factors affect the choice. Here, we aim to analyze the diagnostic power of different NGS techniques applied in HSP, by reviewing 38 selected studies in which different strategies were applied in different-sized cohorts of patients with genetically uncharacterized HSP.

Diagnosis and management of glycogen storage disease type IV, including adult polyglucosan body disease: A clinical practice resource

Glycogen storage disease type IV (GSD IV) is an ultra-rare autosomal recessive disorder caused by pathogenic variants in GBE1 which results in reduced or deficient glycogen branching enzyme activity. Consequently, glycogen synthesis is impaired and leads to accumulation of poorly branched glycogen known as polyglucosan. GSD IV is characterized by a remarkable degree of phenotypic heterogeneity with presentations in utero, during infancy, early childhood, adolescence, or middle to late adulthood. The clinical continuum encompasses hepatic, cardiac, muscular, and neurologic manifestations that range in severity. The adult-onset form of GSD IV, referred to as adult polyglucosan body disease (APBD), is a neurodegenerative disease characterized by neurogenic bladder, spastic paraparesis, and peripheral neuropathy. There are currently no consensus guidelines for the diagnosis and management of these patients, resulting in high rates of misdiagnosis, delayed diagnosis, and lack of standardized clinical care. To address this, a group of experts from the United States developed a set of recommendations for the diagnosis and management of all clinical phenotypes of GSD IV, including APBD, to support clinicians and caregivers who provide long-term care for individuals with GSD IV. The educational resource includes practical steps to confirm a GSD IV diagnosis and best practices for medical management, including (a) imaging of the liver, heart, skeletal muscle, brain, and spine, (b) functional and neuromusculoskeletal assessments, (c) laboratory investigations, (d) liver and heart transplantation, and (e) long-term follow-up care. Remaining knowledge gaps are detailed to emphasize areas for improvement and future research.

Clinical and genetic analyses of premature mitochondrial encephalopathy with epilepsia partialis continua caused by novel biallelic NARS2 mutations

Biallelic NARS2 mutations can cause various neurodegenerative diseases, leading to growth retardation, intractable epilepsy, and hearing loss in early infancy and further progressing to spastic paraplegia, neurodegeneration, and even death. NARS2 mutations are associated with mitochondrial dysfunction and cause combined oxidative phosphorylation deficiency 24 (COXPD24). Relatively few cases have been reported worldwide; therefore, the pathogenesis of COXPD24 is poorly understood. We studied two unrelated patients with COXPD24 with similar phenotypes who presented with intractable refractory epilepsia partialis continua, hearing loss, and growth retardation. One patient died from epilepsy. Three novel NARS2 variants (case 1: c.185T > C and c.251 + 2T > G; case 2: c.185T > C and c.509T > G) were detected with whole-exome sequencing. c.251 + 2T > G is located at the donor splicing site in the non-coding sequence of the gene. The minigene experiment further verified that c.251 + 2T > G caused variable splicing abnormalities and produced truncated proteins. Molecular dynamics studies showed that c.185T > C and c.509T > G reduced the binding free energy of the NARS2 protein dimer. The literature review revealed fewer than 30 NARS2 variants. These findings improved our understanding of the disease phenotype and the variation spectrum and revealed the potential pathogenic mechanism of non-coding sequence mutations in COXPD24.

Selective degradation of tRNASer(AGY) is the primary driver for mitochondrial seryl-tRNA synthetase-related disease

Mitochondrial translation is of high significance for cellular energy homeostasis. Aminoacyl-tRNA synthetases (aaRSs) are crucial translational components. Mitochondrial aaRS variants cause various human diseases. However, the pathogenesis of the vast majority of these diseases remains unknown. Here, we identified two novel SARS2 (encoding mitochondrial seryl-tRNA synthetase) variants that cause a multisystem disorder. c.654-14T > A mutation induced mRNA mis-splicing, generating a peptide insertion in the active site; c.1519dupC swapped a critical tRNA-binding motif in the C-terminus due to stop codon readthrough. Both mutants exhibited severely diminished tRNA binding and aminoacylation capacities. A marked reduction in mitochondrial tRNASer(AGY) was observed due to RNA degradation in patient-derived induced pluripotent stem cells (iPSCs), causing impaired translation and comprehensive mitochondrial function deficiencies. These impairments were efficiently rescued by wild-type SARS2 overexpression. Either mutation caused early embryonic fatality in mice. Heterozygous mice displayed reduced muscle tissue-specific levels of tRNASers. Our findings elucidated the biochemical and cellular consequences of impaired translation mediated by SARS2, suggesting that reduced abundance of tRNASer(AGY) is a key determinant for development of SARS2-related diseases.

Genetic origin of patients having spastic paraplegia with or without other neurologic manifestations

Background

Hereditary spastic paraplegia (HSP) is a group of neurodegenerative diseases characterized by lower-limb spastic paraplegia with highly genetic and clinical heterogeneity. However, the clinical sign of spastic paraplegia can also be seen in a variety of hereditary neurologic diseases with bilateral corticospinal tract impairment. The purpose of this study is to identify the disease spectrum of spastic paraplegia, and to broaden the coverage of genetic testing and recognize clinical, laboratorial, electrophysiological and radiological characteristics to increase the positive rate of diagnosis.

Methods

Twenty-seven cases were screened out to have definite or suspected pathogenic variants from clinically suspected HSP pedigrees through HSP-associated sequencing and/or expanded genetic testing. One case was performed for enzyme detection of leukodystrophy without next-generation sequencing. In addition, detailed clinical, laboratorial, electrophysiological and radiological characteristics of the 28 patients were presented.

Results

A total of five types of hereditary neurological disorders were identified in 28 patients, including HSP (15/28), leukodystrophy (5/28), hereditary ataxia (2/28), methylmalonic acidemia/methylenetetrahydrofolate reductase deficiency (5/28), and Charcot-Marie-tooth atrophy (1/28). Patients in the HSP group had chronic courses, most of whom were lower limbs spasticity, mainly with axonal neuropathy, and thinning corpus callosum, white matter lesions and cerebellar atrophy in brain MRI. In the non-HSP groups, upper and lower limbs both involvement was more common. Patients with homocysteine remethylation disorders or Krabbe’s disease or autosomal recessive spastic ataxia of Charlevoix-Saguenay had diagnostic results in laboratory or imaging examination. A total of 12 new variants were obtained.

Conclusions

HSP had widespread clinical and genetic heterogeneity, and leukodystrophy, hereditary ataxia, Charcot-Marie-Tooth atrophy and homocysteine remethylation disorders accounted for a significant proportion of the proposed HSP. These diseases had different characteristics in clinical, laboratorial, electrophysiological, and radiological aspects, which could help differential diagnosis. Genetic analysis could ultimately provide a clear diagnosis, and broadening the scope of genetic testing could improve the positive rate of diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02708-z.

Study of novel NARS2 variants in patient of combined oxidative phosphorylation deficiency 24

BACKGROUND

NARS2 catalyzes the attachment of asparagine amino acids to mitochondrial tRNA^Asn and is critical for efficient mitochondrial protein synthesis. Biallelic variants in NARS2 are associated with combined oxidative phosphorylation deficiency 24 (COXPD24) and autosomal recessive deafness-94.

METHODS

Patient information was obtained after recruitment. Genetic tests were performed using whole exome sequencing (WES) and Sanger sequencing. Structure prediction was based on the RaptorX and SWISS-MODEL platforms. The mRNA analysis of paternal variant was performed. Expression levels and dimerization of wild-type (WT) and mutant NARS2 were detected in human embryonic kidney (HEK) 293T cells. Mitochondrial localization of NARS2 variants was determined using immunofluorescence staining.

RESULTS

The patient presented early onset generalized epilepsy, myoclonic seizures, severe bilateral hearing impairment and affected liver and heart. WES identified two compound heterozygous variants in NARS2: c.1141A>G/p.Asn381Asp and c.1290G>C/p.Trp430Cys. In silico analysis predicted that both variants would cause significant and pathogenic changes in secondary structure. NARS2 c.1290G>C is a variant at the first nucleotide of an exon, a location thought to affect mRNA splicing. Although transcriptional experiments did not identify aberrant splicing, we observed a lower proportion of transcripts from the NARS2 c.1290G>C variant. An in vitro experiment showed that both variants impaired NARS2 expression, while mitochondrial localization and dimerization remained unaffected.

CONCLUSIONS

The patient was diagnosed with COXPD24 caused by novel NARS2 variations. The cardiac dysfunction is identified for the first time. In vitro study revealed impairment of variants on NARS2 expression. These data enrich our knowledge regarding the phenotypic and genotypic spectra of NARS2.

A novel variant of SPAST in a pedigree with pure hereditary spastic paraplegia in Yunnan Province

BACKGROUND

Hereditary spastic paraplegia (HSP) is a rare group of genetically heterogeneous, neurodegenerative disorders. The aim of this study was to identify pathological candidate genes and variants in a large pedigree cohort of 11 purely HSP patients in Yunnan Province.

METHODS

Whole-exome sequencing (WES) was applied to 2 HSP patients and 1 control patient to screen out the candidate gene variants. Then, filtration and verification of these pathological variants were performed by Sanger sequencing.

RESULTS

After the raw data were filtered, two genes with novel variations (SPAST: c.1510 C>T, p.Gln504X, RefSeq.NM_199436; DNAJC16: c.718 C>T, p.Q240X, Ref Seq NM_015291) were identified. The accession numbers of the genes in the ClinVar database were SCV001573094 and SCV001573804, respectively. One gene with a reported single nucleotide polymorphism (CPT1C: rs150853576) was filtered as a candidate variant. Using Sanger sequencing, the novel SPAST gene (protein: Spastin) variant leading to a predicted premature termination and an 18% deletion of the SPAST/spastic paraplegia type 4 (SPG4) protein was confirmed to exist only in affected individuals. The candidate CPT1C and DNAJC16 variants were verified in almost all HSP patients, with one exception.

CONCLUSIONS

Considering that the clinical symptoms and time of onset of HSP are highly heterogeneous, the SPAST as a genotype-phenotype cosegregated variant might be the causative gene of this pedigree, and the other two variants might present cumulative risks to the occurrence and progression of HSP. These three candidate genes with or without novel variants may be potential contributors to disease onset, and therefore useful diagnostic and therapeutic biomarkers. Further research is required to confirm the functions of these genes.

Novel variants in the NARS2 gene as a cause of infantile-onset severe epilepsy leading to fatal refractory status epilepticus: case study and literature review

Biallelic variants in the NARS2 gene are the cause of a continuous spectrum of neurodegenerative disorders presenting with various severity-from spastic paraplegia, progressive neurodegeneration to Leigh and Alpers syndrome. Common clinical signs result from a mitochondrial dysfunction based on OXPHOS deficiency. Here, we present a patient with infantile-onset severe epilepsy leading to fatal refractory status epilepticus. Whole exome sequencing with Exomiser analysis based on HPO terms detected two novel NARS2 variants in a compound heterozygous state. To date, 18 different NARS2 disease-causing mutations have been described. Our study adds to the understanding of this mitochondrial disorder.

GBE1-related disorders: Adult polyglucosan body disease and its neuromuscular phenotypes

Adult polyglucosan body disease (APBD) represents a complex autosomal recessive inherited neurometabolic disorder due to homozygous or compound heterozygous pathogenic variants in GBE1 gene, resulting in deficiency of glycogen-branching enzyme and secondary storage of glycogen in the form of polyglucosan bodies, involving the skeletal muscle, diaphragm, peripheral nerve (including autonomic fibers), brain white matter, spinal cord, nerve roots, cerebellum, brainstem and to a lesser extent heart, lung, kidney, and liver cells. The diversity of new clinical presentations regarding neuromuscular involvement is astonishing and transformed APBD in a key differential diagnosis of completely different clinical conditions, including axonal and demyelinating sensorimotor polyneuropathy, progressive spastic paraparesis, motor neuronopathy presentations, autonomic disturbances, leukodystrophies or even pure myopathic involvement with limb-girdle pattern of weakness. This review article aims to summarize the main clinical, biochemical, genetic, and diagnostic aspects regarding APBD with special focus on neuromuscular presentations.

Phenotypic diversity in an international Cure VCP Disease registry

Background

Dominant mutations in valosin-containing protein (VCP) gene cause an adult onset inclusion body myopathy, Paget’s disease of bone, and frontotemporal dementia also termed multisystem proteinopathy (MSP). The genotype-phenotype relationships in VCP-related MSP are still being defined; in order to understand this better, we investigated the phenotypic diversity and patterns of weakness in the Cure VCP Disease Patient Registry.

Methods

Cure VCP Disease, Inc. was founded in 2018 for the purpose of connecting patients with VCP gene mutations and researchers to help advance treatments and cures. Cure VCP Disease Patient Registry is maintained by Coordination of Rare Diseases at Sanford. The results of two questionnaires with a 5-point Likert scale questions regarding to patients’ disease onset, symptoms, and daily life were obtained from 59 participants (28 males and 31 females) between June 2018 and May 2020. Independent of the registry, 22 patients were examined at the Cure VCP Disease annual patient conference in 2019.

Results

In the questionnaires of the registry, fifty-three patients (90%) reported that they were with inclusion body myopathy, 17 patients (29%) with Paget’s disease of bone, eight patients (14%) with dementia, two patients (3%) with amyotrophic lateral sclerosis, and a patient with parkinsonism. Thirteen patients (22%) reported dysphagia and 25 patients (42%) reported dyspnea on exertion. A self-reported functional rating scale for motor function identified challenges with sit to stand (72%), walking (67%), and climbing stairs (85%). Thirty-five (59%) patients in the registry answered that their quality of life is more than good. As for the weakness pattern of the 22 patients who were evaluated at the Cure VCP Disease annual conference, 50% of patients had facial weakness, 55% had scapular winging, 68% had upper proximal weakness, 41% had upper distal weakness, 77% had lower proximal, and 64% had lower distal weakness.

Conclusions

The Cure VCP Disease Patient Registry is useful for deepening the understanding of patient daily life, which would be a basis to develop appropriate clinical outcome measures. The registry data is consistent with previous studies evaluating VCP patients in the clinical setting. Patient advocacy groups are essential in developing and maintaining disease registries.

Hereditary spastic paraplegia SPG8 mutations impair CAV1-dependent, integrin-mediated cell adhesion

Mutations in WASHC5 (also known as KIAA0196) cause autosomal dominant hereditary spastic paraplegia (HSP) type SPG8. WASHC5, commonly called strumpellin, is a core component of the Wiskott-Aldrich syndrome protein and SCAR homolog (WASH) complex that activates actin nucleation at endosomes. Although various other cellular roles for strumpellin have also been described, none account for how SPG8-associated mutations lead to HSP. Here, we identified protein interactors of the WASH complex by immunoprecipitation and mass spectrometry and assessed the functions of strumpellin in cultured cells using both overexpression and RNA interference along with cell-spreading assays to investigate cell adhesion. We uncovered a decrease in CAV1 protein abundance as well as endosomal fission defects resulting from pathogenic SPG8 mutations. CAV1, a key component of caveolae, interacted with strumpellin in cells, and strumpellin inhibited the lysosomal degradation of CAV1. SPG8-associated missense mutations in strumpellin did not rescue endosomal tubulation defects, reduction in CAV1 protein abundance, or integrin-mediated cell adhesion in strumpellin-deficient cells. Mechanistically, we demonstrated that the WASH complex maintained CAV1 and integrin protein amounts by inhibiting their lysosomal degradation through its endosomal actin nucleation activity. In addition, the interaction of strumpellin with CAV1 stimulated integrin recycling, thereby promoting cell adhesion. These findings provide a molecular link between WASHC5 mutations and impairment of CAV1- and integrin-mediated cell adhesion, providing insights into the cellular pathogenesis of SPG8.

Next Generation Molecular Diagnosis of Hereditary Spastic Paraplegias: An Italian Cross-Sectional Study

Hereditary spastic paraplegia (HSP) refers to a group of genetically heterogeneous neurodegenerative motor neuron disorders characterized by progressive age-dependent loss of corticospinal motor tract function, lower limb spasticity, and weakness. Recent clinical use of next generation sequencing (NGS) methodologies suggests that they facilitate the diagnostic approach to HSP, but the power of NGS as a first-tier diagnostic procedure is unclear. The larger-than-expected genetic heterogeneity-there are over 80 potential disease-associated genes-and frequent overlap with other clinical conditions affecting the motor system make a molecular diagnosis in HSP cumbersome and time consuming. In a single-center, cross-sectional study, spanning 4 years, 239 subjects with a clinical diagnosis of HSP underwent molecular screening of a large set of genes, using two different customized NGS panels. The latest version of our targeted sequencing panel (SpastiSure3.0) comprises 118 genes known to be associated with HSP. Using an in-house validated bioinformatics pipeline and several in silico tools to predict mutation pathogenicity, we obtained a positive diagnostic yield of 29% (70/239), whereas variants of unknown significance (VUS) were found in 86 patients (36%), and 83 cases remained unsolved. This study is among the largest screenings of consecutive HSP index cases enrolled in real-life clinical-diagnostic settings. Its results corroborate NGS as a modern, first-step procedure for molecular diagnosis of HSP. It also disclosed a significant number of new mutations in ultra-rare genes, expanding the clinical spectrum, and genetic landscape of HSP, at least in Italy.