The expanding role of endobronchial ultrasound in patients with centrally located intrapulmonary tumors.

OBJECTIVES: Tissue acquisition of lung tumors is crucial for diagnostic and treatment purposes. In patients with centrally located lung tumors without endobronchial abnormalities the yield of conventional bronchoscopy is poor. Objective of this study was to assess diagnostic yield of EBUS-TBNA in patients with lung tumors, located near or adjacent to the major airways. METHODS: International multicenter retrospective analysis (2013-2018) of linear EBUS databases in Bologna, Italy and Amsterdam, The Netherlands. Patients with a centrally-located lung tumor without endobronchial abnormalities who underwent lung tumor search with linear EBUS were included. Diagnostic yield, feasibility of EBUS guided tumor sampling, complication rate, adequacy of the aspirates for mutational analysis, and assessment of mediastinal/vascular invasion (T4) were evaluated. RESULTS AND CONCLUSION: Real-time EBUS-TBNA diagnostic yield to sample centrally located intrapulmonary tumor was 83% (136/163) and it was independent of tumor location (paratracheal, mainstem, lobar, segmental bronchus). The feasibility to sample the lung tumor was 89% (145/163). In 4 cases the tumor was not found with EBUS. In the other 14 cases, tumor sampling was not performed due to: loss of the echo window after needle insertion [n = 3], interposition of a large vessel [n = 7], switch to radial EBUS [n = 1], switch and sampling through EUS or EUS-B [n = 3]. No major complications occurred. Mutational analysis was successful in 54/63 (86%) of samples. Using surgery as reference standard, EBUS proved more reliable than CT (24/24, 100% versus 22/24, 91.7%, respectively) in the assessment of mediastinal/vascular tumor invasion (T4 status). IN CONCLUSION: Lung tumors presenting without endobronchial abnormalities and located adjacent to the major airways can be safely sampled by EBUS-TBNA resulting in high diagnostic yield irrespective of tumor location. Successful molecular profiling and reliable assessment of mediastinal/vascular invasion (T4) in patients with advanced disease provide additional value to EBUS procedures in the setting of centrally-located lung lesions.

Effects of short-to-long term enzyme replacement therapy (ERT) on skeletal muscle tissue in late onset Pompe disease (LOPD).

AIMS: Pompe disease is an autosomal recessive lysosomal storage disorder resulting from deficiency of acid α-glucosidase (GAA) enzyme. Histopathological hallmarks in skeletal muscle tissue are fibre vacuolization and autophagy. Since 2006, enzyme replacement therapy (ERT) is the only approved treatment with human recombinant GAA alglucosidase alfa. We designed a study to examine ERT-related skeletal muscle changes in 18 modestly to moderately affected late onset Pompe disease (LOPD) patients along with the relationship between morphological/biochemical changes and clinical outcomes. Treatment duration was short-to-long term. METHODS: We examined muscle biopsies from 18 LOPD patients at both histopathological and biochemical level. All patients underwent two muscle biopsies, before and after ERT administration respectively. The study is partially retrospective because the first biopsies were taken before the study was designed, whereas the second biopsy was always performed after at least 6 months of ERT administration. RESULTS: After ERT, 15 out of 18 patients showed improved 6-min walking test (6MWT; P = 0.0007) and most of them achieved respiratory stabilization. Pretreatment muscle biopsies disclosed marked histopathological variability, ranging from an almost normal pattern to a severe vacuolar myopathy. After treatment, we detected morphological improvement in 15 patients and worsening in three patients. Post-ERT GAA enzymatic activity was mildly increased compared with pretreatment levels in all patients. Protein levels of the mature enzyme increased in 14 of the 18 patients (mean increase = +35%; P < 0.05). Additional studies demonstrated an improved autophagic flux after ERT in some patients. CONCLUSIONS: ERT positively modified skeletal muscle pathology as well as motor and respiratory outcomes in the majority of LOPD patients.

Oral field cancerization: history and future perspectives.

Notwithstanding extended surgical approaches or adjuvant chemoradiotherapy, the development of multiple neoplastic lesions arising in the oral cavity after treatment still represents a critical clinical challenge in the management of patients with oral squamous cell carcinoma. Such clinical behavior of oral squamous cell carcinoma is nowadays better known as "field" cancerization effect as suggested by Slaughter, the author that for the first time tried to describe it in a scientific paper. Field cancerization is now widely accepted not only in head and neck oncology but also in other anatomical districts as well as in different types of epithelial neoplasia. A brief history of the theory of field cancerization is here proposed and future perspectives deriving from new molecular techniques are discussed.

Clonal analysis as a prognostic factor in multiple oral squamous cell carcinoma.

OBJECTIVES: A novel classification based on molecular methods to assess clonality defines three types of secondary oral squamous cell carcinoma (OSCC): second primary tumour (SPT) independent from the index tumour, local recurrence (LR), clonally related to the primary tumour, and second field tumour (SFT), derived from the same genetically altered mucosal field as the primary tumour. The present study applied mtDNA analysis in a group of patients experiencing a second loco-regional neoplastic manifestation. The purpose was to differentiate secondary tumours into LRs, SPTs and SFTs and evaluate the prognostic impact in terms of survival rate. MATERIAL AND METHODS: The study population comprised 23 patients who experienced a second neoplastic lesion after a surgical resection of primary OSCC. mtDNA D-loop analysis was applied in paired neoplastic lesions and in clinically and histologically normal mucosa. On the basis of mtDNA results, the second OSCC was classified as LR or SPT or SFT. Disease-free survival was defined as the duration between the appearance of the second neoplastic lesion and death of disease, or last follow-up visit. RESULTS: Seven secondary tumours were classified as LR, 12 as SFT, 4 as SPT. An altered mucosal field proved a variable significantly related to a better survival rate (p<0.05); 2/12 (16.6%) SFT events failed as compared to 5/7 LRs (71.4%) and 3/4 SPTs (75%). CONCLUSION: mtDNA analysis may be considered a useful tool to differentiate secondary tumours and might influence the choice of the most appropriate treatment in patients with multiple OSCCs.

The impact of field cancerization on the extent of duct carcinoma in situ (DCIS) in breast tissue after conservative excision.

AIM: Aim of the present study is to evaluate the risk of residual neoplastic foci, in patients treated with breast conservative surgery, based on duct carcinoma in situ (DCIS) grading. MATERIALS AND METHODS: The study is based on a retrospective analysis of 419 resection specimens relative to 161 patients. All these patients underwent surgical re-excision when the first specimen had shown one or more margins involved by DCIS. Margins were oriented and the side of margin involved was recorded. Clonal analysis, using the mitochondrial DNA (mtDNA) technique, was obtained in selected cases. RESULTS: Residual neoplastic foci were found in 145 out of 419 (34.6%) re-excised specimens. Specifically, residual foci of DCIS grade 2 and 3 were found more frequently in the margin facing the nipple (33.3% and 51.6%, respectively). On the contrary foci of DCIS grade 1 did not show any specific distribution. Clonal mt DNA analysis evidenced that DCIS grade 3 foci present in the re-excision specimens were genetically similar to the tumor removed in the first specimen, while DCIS grade 1 foci were not clonally related each other. CONCLUSIONS: The present data further confirm that DCIS grade 3 is characterized by a circumscribed neoplastic process extending along the large ducts probably of a single mammary lobe. On the contrary DCIS grade 1 is characterized by multiple independent neoplastic foci, dispersed through several lobes indicating a field where multiple independent foci of cancer harbor.

MYH7-related myopathies: clinical, histopathological and imaging findings in a cohort of Italian patients.

BACKGROUND: Myosin heavy chain 7 (MYH7)-related myopathies are emerging as an important group of muscle diseases of childhood and adulthood, with variable clinical and histopathological expression depending on the type and location of the mutation. Mutations in the head and neck domains are a well-established cause of hypertrophic cardiomyopathy whereas mutation in the distal regions have been associated with a range of skeletal myopathies with or without cardiac involvement, including Laing distal myopathy and Myosin storage myopathy. Recently the spectrum of clinical phenotypes associated with mutations in MYH7 has increased, blurring this scheme and adding further phenotypes to the list. A broader disease spectrum could lead to misdiagnosis of different congenital myopathies, neurogenic atrophy and other neuromuscular conditions. RESULTS: As a result of a multicenter Italian study we collected clinical, histopathological and imaging data from a population of 21 cases from 15 families, carrying reported or novel mutations in MYH7. Patients displayed a variable phenotype including atypical pictures, as dropped head and bent spine, which cannot be classified in previously described groups. Half of the patients showed congenital or early infantile weakness with predominant distal weakness. Conversely, patients with later onset present prevalent proximal weakness. Seven patients were also affected by cardiomyopathy mostly in the form of non-compacted left ventricle. Muscle biopsy was consistent with minicores myopathy in numerous cases. Muscle MRI was meaningful in delineating a shared pattern of selective involvement of tibialis anterior muscles, with relative sparing of quadriceps. CONCLUSION: This work adds to the genotype-phenotype correlation of MYH7-relatedmyopathies confirming the complexity of the disorder.

LOPED study: looking for an early diagnosis in a late-onset Pompe disease high-risk population.

OBJECTIVE: A multicentre observational study was aimed to assess the prevalence of late-onset Pompe disease (LOPD) in a large high-risk population, using the dried blood spot (DBS) as a main screening tool. DESIGN/METHODS: 17 Italian neuromuscular centres were involved in the late-onset Pompe early diagnosis (LOPED) study. Inclusion criteria were: (1) age ≥5 years, (2) persistent hyperCKaemia and (3) muscle weakness at upper and/or lower limbs (limb-girdle muscle weakness, LGMW). Acid α-glucosidase (GAA) activity was measured separately on DBS by fluorometric as well as tandem mass spectrometry methods. A DBS retest was performed in patients resulted positive at first assay. For the final diagnosis, GAA deficiency was confirmed by a biochemical assay in skeletal muscle, whereas genotype was assessed by GAA molecular analysis. RESULTS: In a 14-month period, we studied 1051 cases: 30 positive samples (2.9%) were detected by first DBS screening, whereas, after retesting, 21 samples were still positive. Biochemical and molecular genetic studies finally confirmed LOPD diagnosis in 17 cases (1.6%). The median time from the onset of symptoms/signs to diagnosis was 5 years. Among those patients, 35% showed presymptomatic hyperCKaemia and 59% showed hyperCKaemia+LGMW, whereas 6% manifested with LGMW. CONCLUSIONS: LOPED study suggests that GAA activity should be accurately screened by DBS in all patients referring for isolated hyperCKaemia and/or LGMW. A timely diagnosis was performed in five patients with presymptomatic hyperCKaemia, but two had already manifested with relevant changes on muscle morphology and MRI. Consequently, enzyme replacement therapy was started in 14/17 patients, including the 2 patients still clinically presymptomatic but with a laboratory evidence of disease progression.

Pathological spectrum in recurrences of glioblastoma multiforme.

INTRODUCTION: Glioblastoma (GBM) is the most frequent primary malignant brain tumour. Despite advances in treatment its prognosis remains poor. Histological features of GBM are well known. On the contrary histological description of recurrences is still not available. The aim of this study was to describe the morphological, immunohistochemical and molecular features of recurrent GBMs. METHODS: 25 recurrent GBMs, diagnosed after 2005, were collected. All patients had undergone an adjuvant treatment regimen (temozolomide and/or radiotherapy). All cases were immunostained using anti-GFAP, Olig2 and Nogo-A antisera. MGMT and IDH1 status was reassessed. Features of the recurrences were compared with those of primary GBMs, time of recurrence and survival. RESULTS: Recurrences were divided morphologically into three groups: 1) recurrences displaying the same features of primary GBM, were highly cellular, had the fastest progression and the worst prognosis; 2) recurrences changing dramatically morphological appearance, had a slightly longer survival, 3) poorly cellular recurrences, with sparse neoplastic cells intermingled with reactive and necrotic tissue, displayed the slowest progression and longer survival. MGMT and IDH1 status remained unchanged between primary tumours and recurrences. DISCUSSION: GBM histological subtypes display different reactions to adjuvant treatments, offering a possible role in predicting different recurrence and survival time.

ClC-1 mutations in myotonia congenita patients: insights into molecular gating mechanisms and genotype-phenotype correlation.

KEY POINTS: Loss-of-function mutations of the skeletal muscle ClC-1 channel cause myotonia congenita with variable phenotypes. Using patch clamp we show that F484L, located in the conducting pore, probably induces mild dominant myotonia by right-shifting the slow gating of ClC-1 channel, without exerting a dominant-negative effect on the wild-type (WT) subunit. Molecular dynamics simulations suggest that F484L affects the slow gate by increasing the frequency and the stability of H-bond formation between E232 in helix F and Y578 in helix R. Three other myotonic ClC-1 mutations are shown to produce distinct effects on channel function: L198P shifts the slow gate to positive potentials, V640G reduces channel activity, while L628P displays a WT-like behaviour (electrophysiology data only). Our results provide novel insight into the molecular mechanisms underlying normal and altered ClC-1 function. ABSTRACT: Myotonia congenita is an inherited disease caused by loss-of-function mutations of the skeletal muscle ClC-1 chloride channel, characterized by impaired muscle relaxation after contraction and stiffness. In the present study, we provided an in-depth characterization of F484L, a mutation previously identified in dominant myotonia, in order to define the genotype-phenotype correlation, and to elucidate the contribution of this pore residue to the mechanisms of ClC-1 gating. Patch-clamp recordings showed that F484L reduced chloride currents at every tested potential and dramatically right-shifted the voltage dependence of slow gating, thus contributing to the mild clinical phenotype of affected heterozygote carriers. Unlike dominant mutations located at the dimer interface, no dominant-negative effect was observed when F484L mutant subunits were co-expressed with wild type. Molecular dynamics simulations further revealed that F484L affected the slow gate by increasing the frequency and stability of the H-bond formation between the pore residue E232 and the R helix residue Y578. In addition, using patch-clamp electrophysiology, we characterized three other myotonic ClC-1 mutations. We proved that the dominant L198P mutation in the channel pore also right-shifted the voltage dependence of slow gating, recapitulating mild myotonia. The recessive V640G mutant drastically reduced channel function, which probably accounts for myotonia. In contrast, the recessive L628P mutant produced currents very similar to wild type, suggesting that the occurrence of the compound truncating mutation (Q812X) or other muscle-specific mechanisms accounted for the severe symptoms observed in this family. Our results provide novel insight into the molecular mechanisms underlying normal and altered ClC-1 function.

Adult polyglucosan body disease: clinical and histological heterogeneity of a large Italian family.

Adult Polyglucosan Body Disease (APBD) is a rare inherited leukodystrophy associated with axonal polyneuropathy, mainly reported in persons of Ashkenazi-Jewish descent. We describe three Italian siblings at disease onset, presenting in their fifties with a combination of pyramidal and ataxic signs, mild demyelinating neuropathy on neurophysiological investigation (1/3 cases) and transient symptoms (1/3). A leucoencephalopathy with infratentorial lesions without enhancement and medullary/spine atrophy was demonstrated on brain/spine MRI (3/3). Muscle biopsy was normal in 2/3; both muscle and nerve biopsy showed polyglucosan bodies in the sibling with polyneuropathy. This indicated a need for GBE1 sequencing, which revealed a novel missense mutation (c.1064G>A; p.Arg355His) and one previously described (c.1604A>G; p.Tyr535Cys) in all siblings. We highlight that peripheral neuropathy, deemed as disease hallmark, may be missing and that transient symptoms are confirmed as early disease manifestations. The pattern of damage at neuro-imaging described recurs irrespective of clinical presentation, constituting a unifying diagnostic clue.

Non-coding VMA21 deletions cause X-linked myopathy with excessive autophagy.

X-linked Myopathy with Excessive Autophagy (XMEA) affects proximal muscles of the lower extremities and follows a progressive course reminiscent of muscular dystrophy. It is caused by mutations in VMA21 whose protein product assembles lysosomes' proton pumps. All XMEA mutations to date have been single-nucleotide substitutions that reduce VMA21 expression, which leads to modest lysosomal pH increase, the first step in the disease's pathogenesis. We now report a new class of XMEA mutations. We identified two VMA21 non-coding microdeletions, one intronic (c.54-16_54-8del), the other in the 3'UTR (c.*13_*104del). Both resulted in a relatively more severe (early ambulation loss), diffuse (extra-ocular and upper extremity involvement), and early (neonatal) onset disease compared to previously reported patients. Our cases highlight the importance of including non-coding regions of VMA21 in genetic testing panels of dystrophies and myopathies. Specific diagnosis of XMEA will be particularly important as therapies aimed at correcting the modest rise in lysosomal pH at the root of this disease are developed.

Adult polyglucosan body disease in a patient originally diagnosed with Fabry's disease.

Adult polyglucosan body disease is a rare autosomal recessive disease, caused by glycogen branching enzyme gene mutations, characterised by urinary dysfunction, spastic paraplegia with vibration sense loss, peripheral neuropathy, and cognitive impairment. Fabry's disease is an X-linked lysosomal storage disorder caused by α-galactosidase A gene mutations; neurological manifestations include cerebrovascular accidents, small-fibre neuropathy and autonomic dysfunction. Here, we report the case of a 44-year-old Sicilian male with stroke-like episodes, hypohidrosis and mild proteinuria, which led to the diagnosis of Fabry's disease after a hemizygous mutation (p.Ala143Thr) in α-galactosidase A gene was detected. Subsequently, he developed progressive walking difficulties and dementia, which were considered atypical for Fabry's disease. Therefore, we performed additional investigations that eventually led to the diagnosis of adult polyglucosan body disease caused by two novel missense mutations (p.Asp413His and p.Gly534Val) in the glycogen branching enzyme gene. Recently, the pathogenic role of the p.Ala143Thr mutation in causing Fabry's disease has been questioned. This case underlines the importance of performing further investigations when facing with atypical features even in the presence of a genetic diagnosis of a rare disease.

Randomized Controlled Trials and real life studies. Approaches and methodologies: a clinical point of view.

Randomized Controlled Trials (RCTs) are the "gold standard" for evaluating treatment outcomes providing information on treatments "efficacy". They are designed to test a therapeutic hypothesis under optimal setting in the absence of confounding factors. For this reason they have high internal validity. The strict and controlled conditions in which they are conducted, leads to low generalizability because they are performed in conditions very different from real life usual care. Conversely, real life studies inform on the "effectiveness" of a treatment, that is, the measure of the extent to which an intervention does what is intended to do in routine circumstances. At variance to RCTs, real life trials have high generalizability, but low internal validity. Recently the number of real life studies has been rapidly growing in different areas of respiratory medicine, particularly in asthma and COPD. The role of such studies is becoming a hot topic in respiratory medicine, attracting research interest and debate. In the first part of this review we discuss some of the advantages and disadvantages of different types of RCTs and analyze the strengths and weaknesses of real life trials, considering the recent examples of some studies conducted in COPD. We then discuss methodological approaches and options to overcome some of the limitations of real life studies. Comparing the conclusions of effectiveness and efficacy trials can provide important pieces of information. Indeed, these approaches can result complementary, and they can guide the interpretation of each other results.

A fourth case of POMT2-related limb girdle muscle dystrophy with mild reduction of α-dystroglycan glycosylation.

BACKGROUND: POMT2 mutations have been identified in Walker-Warburg syndrome or muscle-eye-brain-like, but rarely in limb girdle muscular dystrophy (LGMD). RESULTS: Two POMT2 mutations, one null and one missense, were found in a patient with LGMD and mild mental impairment, no brain or ocular involvement, minor histopathological features, and slight reduction of α-dystroglycan (α-DG) glycosylation and α-DG laminin binding. CONCLUSIONS: Our case, the fourth LGMD POMT2-mutated reported to date, provides further evidence of correlation between level of α-DG glycosylation and phenotype severity.

No evidence of cardiomyopathy in spinal and bulbar muscular atrophy.

OBJECTIVES: Spinal and bulbar muscular atrophy (SBMA) is a lower motor neuron disease caused by a CAG repeat expansion within the androgen receptor (AR) gene. Toxic nuclear accumulation of mutant AR has been observed in tissues other than nervous system including cardiac muscle. Moreover, CAG polymorphism length within AR has been associated with an increased risk of heart disease. MATERIALS AND METHODS: To test the hypothesis of the presence of cardiomyopathy in SBMA, a full cardiac protocol was applied to 25 SBMA patients. RESULTS: Patients' age ranged between 32 and 75 years. Cardiologic examination, 12-lead ECG, and echocardiography showed no abnormalities other than those consistent with hypertensive heart disease. One patient showed frequent supraventricular premature beats in absence of other significant arrhythmias at the 24-h ECG Holter. CONCLUSIONS: Our findings do not support the hypothesis of a primary cardiomyopathy in SBMA.

Respiratory and cardiac function in congenital muscular dystrophies with alpha dystroglycan deficiency.

The aim of this retrospective study was to assess respiratory and cardiac function in a large cohort of patients with congenital muscular dystrophies (CMD) with reduced glycosylation of alphadystroglycan (α-DG). Thirteen of the 115 patients included in the study died between the age of 1 month and 20 years. The age at last follow up of the surviving 102 ranged between 1 year and 68 years (median: 9.3 years). Cardiac involvement was found in 7 of the 115 (6%), 5 with dilated cardiomyopathy, 1 cardiac conductions defects and 1 mitral regurgitation. Respiratory function was impaired in 14 (12%). Ten of the 14 required non invasive nocturnal respiratory support, while the other four required invasive ventilation. Cardiac or respiratory involvement was found in patients with mutations in FKRP, POMT1, POMT2. All of the patients in whom mutation in POMGnT1 were identified had normal cardiac and respiratory function.

Novel POMGNT1 point mutations and intragenic rearrangements associated with muscle-eye-brain disease.

Congenital muscular dystrophies due to defects in genes encoding proteins involved in α-dystroglycan (α-DG) glycosylation are a heterogeneous group of muscle disorders variably associated with central nervous system and eye abnormalities. One of the more severe is muscle-eye-brain disease (MEB). Mutations in genes coding for proven or putative glycosyltransferases (POMT1, POMT2, POMGnT1, fukutin, FKRP, and LARGE), the DPM3 gene encoding a DOL-P-Man synthase subunit, and the DAG1 gene encoding α-dystroglycan, have been associated with altered α-DG glycosylation. We report new POMGnT1 mutations and evaluate protein expression in 3 patients and 2 foetuses with variably severe MEB features. We identify two new point mutations (c.643C>T, c.1863delC), one new intragenic rearrangement (deletion of exons 2-8), and a new intron retention (between exons 21 and 22) resulting from a known point mutation c.1895+1G>T. Our study provides further evidence that rearrangements of the POMGnT1 gene are relatively common. Importantly, if heterozygous, they can be missed on standard genomic DNA sequencing. POMGNT1 protein analysis in 3 patients showed that the severity of the phenotype does not correlate with protein expression. Cerebral MRI is important for identifying MEB and α-dystroglycanopathy phenotypes in children and foetuses, and hence for directing the genetic analysis.

Observational clinical study in juvenile-adult glycogenosis type 2 patients undergoing enzyme replacement therapy for up to 4 years.

The objective of this study was to describe a large Italian cohort of patients with late-onset glycogen storage disease type 2 (GSDII) at various stages of disease progression and to evaluate the clinical effectiveness of alglucosidase alpha enzyme replacement therapy (ERT). Previous studies showed in late-onset patients ERT efficacy against placebo and variable response in uncontrolled studies. Seventy-four juvenile or adult GSDII patients were treated with ERT in a multicenter open label, non-randomized study, from 12 months up to 54 months. Recombinant human alpha glucosidase (rh-GAA) was injected by intravenous route at 20 mg/kg every second week. Patients were divided into three groups according to ERT duration: Group A received treatment for 12-23 months (n = 16), Group B for 24-35 months (n = 14), and Group C for more than 36 months (n = 44). Clinical assessment included a 6-min walk test (6MWT), forced vital capacity (FVC), the Walton and Gardner-Medwin score, the number of hours of ventilation, body mass index, echocardiography and blood creatine kinase (CK). Included in our cohort were 33 males and 41 females (M:F = 0.8:1), with a mean age at first symptoms of 28.3 years (range 2-55 years) and a mean age of 43 years at study entry (range 7-72 years). Seven wheelchair bound patients, as well as 27 patients requiring ventilation support, were included. After treatment we could observe an increase in distance walked on the 6MWT in the large majority of patients (48/58; 83%), with an overall mean increase of 63 m (from 320 ± 161 to 383 ± 178 m). After treatment in the majority of patients FVC was improved or unchanged (45/69; 65%). In ventilated patients we observed an improvement in average number of hours off the ventilator (from 15.6 to 12.1 h). Six patients stopped mechanical ventilation and two others started it. The effect of therapy was not related to ERT duration. Nine of 64 patients (13%) that underwent to echocardiography showed a variable degree of cardiac hypertrophy (left ventriculum or septum), and a positive effect was observed after 36 months of ERT in one adult case. Discontinuation of treatment occurred in four patients: one drop-off case, one patient died for a sepsis after 34 months of treatment and two patients stopped ERT for worsening of general clinical condition. Mild adverse effects were observed in four cases (5%). This study represents the largest cohort of late-onset GSDII patients treated with ERT, and confirm a positive effect of treatment. These results, obtained in a large case series on therapy, indicate a favourable effect of ERT therapy, even in more advanced stage of the disease.