The neurological core features of the infantile-onset multisystem neurologic, endocrine, and pancreatic disease: A novel nonsense mutation in an Italian family.

Aim: Biallelic mutations in the PTRH2 gene have been associated with infantile multisystem neurological, endocrine, and pancreatic disease (IMNEPD), a rare autosomal recessive disorder of variable expressivity characterized by global developmental delay, intellectual disability or borderline IQ level, sensorineural hearing loss, ataxia, and pancreatic insufficiency. Various additional features may be included, such as peripheral neuropathy, facial dysmorphism, hypothyroidism, hepatic fibrosis, postnatal microcephaly, cerebellar atrophy, and epilepsy. Here, we report the first Italian family presenting only predominant neurological features.

Next-generation sequencing in Charcot-Marie-Tooth: a proposal for improvement of ACMG guidelines for variant evaluation.

Background: The application of massive parallel sequencing technologies in the molecular analysis of Charcot-Marie-Tooth (CMT) has enabled the rapid and cost-effective identification of numerous potentially significant variants for diagnostic purposes. The objective is to reduce the number of variants, focusing only on those with pathogenic significance. The 2015 American College of Medical Genetics and Genomics (ACMG) guidelines aid in achieving this goal, but it is now evident that a pathology or gene-specific review of these rules is essential to avoid misinterpretations that may result from blindly applying the criteria.

Phenotypic spectrum of myelin protein zero-related neuropathies: a large cohort study from five mutation clusters across Italy.

Background: We aimed to investigate the clinical features of a large cohort of patients with myelin protein zero ()-related neuropathy, focusing on the five main mutation clusters across Italy.

Methods: We retrospectively gathered a minimal data set of clinical information in a series of patients with these frequent mutations recruited among Italian Charcot-Marie-Tooth (CMT) registry centres, including disease onset/severity (CMTES-CMT Examination Score), motor/sensory symptoms and use of orthotics/aids.

Results: We collected data from 186 patients: 60 had the p.

Early Onset Inherited Peripheral Neuropathies: The Experience of a Specialized Referral Center for Genetic Diagnosis Achievement.

Background: Charcot-Marie-Tooth disease (CMT) is a heterogeneous group of inherited peripheral neuropathies. Although the typical disease onset is reported in the second decade, earlier onsets are not uncommon. To date, few studies on pediatric populations have been conducted and the achievement of molecular diagnosis remains challenging.

Skeletal muscle involvement in biallelic mutations: case report and review of the literature.

Biallelic mutations in the sorbitol dehydrogenase () gene have been identified as a genetic cause of autosomal recessive axonal Charcot-Marie-Tooth disease 2 (CMT2) and distal hereditary motor neuropathy (dHMN). We herein review the main phenotypes associated with mutations and report the case of a 16-year-old man who was referred to our outpatient clinic for a slowly worsening gait disorder with wasting and weakness of distal lower limbs musculature. Since creatine phosphokinase (CPK) values were persistently raised (1.

Case report: Episodic ataxia without ataxia?

Hereditary myopathies represent a clinically and genetically heterogeneous group of neuromuscular disorders, characterized by highly variable clinical presentations and frequently overlapping phenotypes with other neuromuscular disorders, likely influenced by genetic and environmental modifiers. Genetic testing is often challenging due to ambiguous clinical diagnosis. Here, we present the case of a family with clinical and Electromyography (EMG) features resembling a myotonia-like disorder in which Whole Exome Sequencing (WES) analysis revealed the co-segregation of two rare missense variants in and , genes previously associated with episodic ataxia 8 (EA8).

A novel de novo variant in POLR3B gene associated with a primary axonal involvement of the largest nerve fibers.

Background And Aims: POLR3B gene encodes a subunit of RNA polymerase III (Pol III). Biallelic mutations in POLR3B are associated with leukodystrophies, but recently de novo heterozygous mutations have been described in early onset peripheral demyelinating neuropathies with or without central involvement. Here, we report the first Italian case carrying a de novo variant in POLR3B with a pure neuropathy phenotype and primary axonal involvement of the largest nerve fibers.

The SPTLC1 p.S331 mutation bridges sensory neuropathy and motor neuron disease and has implications for treatment.

Aims: SPTLC1-related disorder is a late onset sensory-autonomic neuropathy associated with perturbed sphingolipid homeostasis which can be improved by supplementation with the serine palmitoyl-CoA transferase (SPT) substrate, l-serine. Recently, a juvenile form of motor neuron disease has been linked to SPTLC1 variants. Variants affecting the p.

A novel mutation in COL3A1 associates to vascular Ehlers-Danlos syndrome with predominant musculoskeletal involvement.

Background: Vascular Ehlers-Danlos syndrome (vEDS) is a heritable connective tissue disorder caused by defects in the type III collagen protein. It is generally considered the most severe form of Ehlers-Danlos syndrome (EDS) due to an increased risk of spontaneous artery or organ rupture. vEDS has an extremely heterogeneous presentation and muscle rupture is considered a minor diagnostic criterium.

A novel mutation of Twinkle in Perrault syndrome: A not rare diagnosis?

Perrault syndrome is a rare disorder characterized by ovarian dysgenesis, bilateral sensorineural hearing loss and associated with mutations in six mitochondrial proteins. Additional neurological features were also described. Herein, we report on a 27-year-old woman with Perrault syndrome (PS), moderate ataxia and axonal sensory-motor peripheral neuropathy in whom we identified compound heterozygous mutations in the TWNK gene (p.

Early onset demyelinating Charcot-Marie-Tooth disease caused by a novel in-frame isoleucine deletion in peripheral myelin protein 2.

Peripheral myelin protein 2 (PMP2) is a small protein located on the cytoplasmic side of compact myelin, involved in the lipids transport and in the myelination process. In the last years few families affected with demyelinating Charcot-Marie-Tooth neuropathy (CMT1), caused by PMP2 mutations, have been identified. In this study we describe the first case of a PMP2 in-frame deletion.

Diagnostic Value of Sural Nerve Biopsy: Retrospective Analysis of Clinical Cases From 1981 to 2017.

Nerve biopsy represents the conclusive step in the diagnostic work-up of peripheral neuropathies, and its diagnostic yield is still debated. The aim of this study is to consider the impact of nerve biopsy on reaching a useful diagnosis in different peripheral neuropathies and its changing over time. We retrospectively analyzed 1,179 sural nerve biopsies performed in the period 1981-2017 at Neurological Clinic of Policlinico San Martino (Genoa).

Mutation update for myelin protein zero-related neuropathies and the increasing role of variants causing a late-onset phenotype.

Mutations of myelin protein zero gene (MPZ) are found in 5% of Charcot-Marie-Tooth patients. In 2004, Shy et al. identified two main phenotypes associated with them: an early-onset subtype with mainly demyelinating features and a late-onset subgroup with prominent axonal impairment.

Expanding the spectrum of genes responsible for hereditary motor neuropathies.

Background: Inherited peripheral neuropathies (IPNs) represent a broad group of genetically and clinically heterogeneous disorders, including axonal Charcot-Marie-Tooth type 2 (CMT2) and hereditary motor neuropathy (HMN). Approximately 60%-70% of cases with HMN/CMT2 still remain without a genetic diagnosis. Interestingly, mutations in HMN/CMT2 genes may also be responsible for motor neuron disorders or other neuromuscular diseases, suggesting a broad phenotypic spectrum of clinically and genetically related conditions.

A multicenter retrospective study of charcot-marie-tooth disease type 4B (CMT4B) associated with mutations in myotubularin-related proteins (MTMRs).

Objective: Charcot-Marie-Tooth (CMT) disease 4B1 and 4B2 (CMT4B1/B2) are characterized by recessive inheritance, early onset, severe course, slowed nerve conduction, and myelin outfoldings. CMT4B3 shows a more heterogeneous phenotype. All are associated with myotubularin-related protein (MTMR) mutations.

Role of MAPT in Pure Motor Neuron Disease: Report of a Recurrent Mutation in Italian Patients.

The aim of our study was to evaluate the role of mutations in the MAPT gene in patients with pure amyotrophic lateral sclerosis (ALS). A cohort of 120 ALS patients, both sporadic and familial, without cognitive impairment was analyzed by next-generation sequencing with a multiple-gene panel comprising 23 genes, including MAPT, known to be associated with ALS and frontotemporal dementia. The presence of the C9orf72 expansion was also investigated.

A novel mutation in the N-terminal acting-binding domain of Filamin C protein causing a distal myofibrillar myopathy.

Variants in Filamin C (FLNC) gene may cause either cardiomyopathies or different myopathies. We describe a family affected by a distal myopathy with autosomal dominant inheritance. The onset of the disease was in the third decade with gait impairment due to distal leg weakness.

Autosomal-dominant transthyretin (TTR)-related amyloidosis is not a frequent CMT2 neuropathy "in disguise".

Transthyretin (TTR)-related familial amyloid polyneuropathy (TTR-FAP) is a life-threatening autosomal dominant, systemic disease. First symptoms usually occur from the second to over sixth decade of life with a length-dependent axonal neuropathy with prominent involvement of the small fibers and multi-organ systemic failure.Early diagnosis is pivotal for effective therapeutic options, but it is hampered by the heterogeneity of the clinical spectrum which can lead to misdiagnosis with other neurological condition/disorder such as axonal sensory-motor neuropathy (CMT2) as described in literature.

Spinocerebellar ataxia 17: full phenotype in a 41 CAG/CAA repeats carrier.

Background: Spinocerebellar ataxia 17 (SCA17) is one of the most heterogeneous forms of autosomal dominant cerebellar ataxias with a large clinical spectrum which can mimic other movement disorders such as Huntington disease (HD), dystonia and parkinsonism. SCA17 is caused by an expansion of CAG/CAA repeat in the Tata binding protein () gene. Normal alleles contain 25 to 40 CAG/CAA repeats, alleles with 50 or greater CAG/CAA repeats are pathological with full penetrance.

Twenty years of molecular analyses in amyotrophic lateral sclerosis: genetic landscape of Italian patients.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with a heterogeneous genetic background. Because mutation analysis by Sanger sequencing is costly and time-consuming, in recent years, next-generation sequencing (NGS) techniques have become of much interest. This study analyses the results of 20 years of molecular analyses in ALS patients in our laboratory using traditional methods and NGS.

Two novel cases of compound heterozygous mutations in mitofusin2: Finding out the inheritance.

MFN2 is the major gene involved in the axonal form of Charcot-Marie-Tooth disease. It usually has an autosomal dominant pattern of inheritance, but a few cases of homozygous or compound heterozygous mutations have been described. These patients usually present an earlier onset, more severe phenotype and their inheritance pattern can span from autosomal recessive to semidominant.