Bulbar muscle impairment in patients with late onset Pompe disease: Insight from the French Pompe registry.

BACKGROUND AND PURPOSE: Late onset Pompe disease (LOPD) is a rare neuromuscular disorder caused by a deficit in acid alpha-glucosidase. Macroglossia and swallowing disorders have already been reported, but no study has focused yet on its frequency and functional impact on patients' daily life. METHODS: We reviewed 100 adult LOPD patients followed in 17 hospitals in France included in the French national Pompe disease registry. The Swallowing Quality of Life Questionnaire and the Sydney Swallow Questionnaire were completed by patients, and a specialist carried out a medical examination focused on swallowing and assigned a Salassa score to each patient. Respiratory and motor functions were also recorded. Subgroup analysis compared patients with and without swallowing difficulties based on Salassa score. RESULTS: Thirty-two percent of patients presented with swallowing difficulties, often mild but sometimes severe enough to require percutaneous endoscopic gastrostomy (1%). Daily dysphagia was reported for 20% of our patients and aspirations for 18%; 9.5% were unable to eat away from home. Macroglossia was described in 18% of our patients, and 11% had lingual atrophy. Only 15% of patients presenting with swallowing disorders were followed by a speech therapist. Swallowing difficulties were significantly associated with macroglossia (p = 0.015), longer duration of illness (p = 0.032), and a lower body mass index (p = 0.047). CONCLUSIONS: Swallowing difficulties in LOPD are common and have significant functional impact. Increased awareness by physicians of these symptoms with systematic examination of the tongue and questions about swallowing can lead to appropriate multidisciplinary care with a speech therapist and dietitian if needed.

Description of clinical and genetic features of 122 patients included in the Spanish Pompe registry.

Pompe disease is a rare genetic disorder with an estimated prevalence of 1:60.000. The two main phenotypes are Infantile Onset Pompe Disease (IOPD) and Late Onset Pompe Disease (LOPD). There is no published data from Spain regarding the existing number of cases, regional distribution, clinical features or, access and response to the treatment. We created a registry to collect all these data from patients with Pompe in Spain. Here, we report the data of the 122 patients registered including nine IOPD and 113 LOPD patients. There was a high variability in how the diagnosis was obtained and how the follow-up was performed among different centres. Seven IOPD patients were still alive being all treated with enzymatic replacement therapy (ERT) at last visit. Ninety four of the 113 LOPD patients had muscle weakness of which 81 were receiving ERT. We observed a progressive decline in the results of muscle function tests during follow-up. Overall, the Spanish Pompe Registry is a valuable resource for understanding the demographics, patient's journey and clinical characteristics of patients in Spain. Our data supports the development of agreed guidelines to ensure that the care provided to the patients is standardized across the country.

The impact of COVID-19 infection, the pandemic and its associated control measures on patients with Pompe disease.

BACKGROUND: Patients with Pompe disease, a rare metabolic myopathy, were thought to be at increased risk of severe COVID-19 disease during the pandemic. In addition, the lockdown may have affected their regular treatment. OBJECTIVE: To assess the perceived effect of COVID-19 infection and of the pandemic on the treatment, and physical and mental health of patients with Pompe disease. METHODS: Patients with Pompe disease over 16 years of age participated in an international, cross-sectional, online survey (September 20, 2022-November 7, 2022). The questionnaire, available in eight languages, consisted of 89 questions divided into 3 parts: (A) severity of Pompe disease, (B) COVID-19 precautions and infection(s) and (C) effects of the COVID-19 pandemic. RESULTS: Among 342 respondents, originating from 25 different countries, 47.6% experienced one or more COVID-19 infections. While most recovered within 4 weeks (69.7%) and only eight patients needed to be admitted to the hospital, 42.2% of patients experienced an impact of the infection on their overall condition, respiratory status and/or mobility status. More severely affected patients took more stringent control measures. The pandemic additionally caused interruptions in medical care in many patients (56.0%) and 17.2% of patients experienced interruptions of enzyme replacement therapy. The pandemic also affected many patients' disease severity (27.7%), mental health (55.4%) and feeling of loneliness (43.4%). CONCLUSION: COVID-19 infection(s) and the pandemic affected the treatment, physical health and mental health of patients with Pompe disease, emphasizing the importance of continued patient centered care during a difficult time such as the COVID-19 pandemic.

Population pharmacokinetic modeling and dosing simulation of avalglucosidase alfa for selecting alternative dosing regimen in pediatric patients with late-onset pompe disease.

Avalglucosidase alfa (AVAL) was approved in the United States (2021) for patients with late-onset Pompe disease (LOPD), aged ≥ 1 year. In the present study, pharmacokinetic (PK) simulations were conducted to propose alternative dosing regimens for pediatric LOPD patients based on a bodyweight cut-off. Population PK (PopPK) analysis was performed using nonlinear mixed effect modeling approach on pooled data from three clinical trials with LOPD patients, and a phase 2 study (NCT03019406) with infantile-onset Pompe disease (IOPD: 1-12 years) patients. A total of 2257 concentration-time points from 91 patients (LOPD, n = 75; IOPD, n = 16) were included in the analysis. The model was bodyweight dependent allometric scaling with time varying bodyweight included on clearance and distribution volume. Simulations were performed for two dosing regimens (20 mg/kg or 40 mg/kg) with different bodyweight cut-off (25, 30, 35 and 40 kg) by generating virtual pediatric (1-17 years) and adult patients. Corresponding simulated individual exposures (maximal concentration, Cmax and area under the curve in the 2-week dosing interval, AUC2W), and distributions were calculated. It was found that dosing of 40 mg/kg and 20 mg/kg in pediatric patients < 30 kg and ≥ 30 kg, respectively, achieved similar AVAL exposure (based on AUC2W) to adult patients receiving 20 mg/kg. PK simulations conducted on the basis of this model provided supporting data for the currently approved US labelling for dosing adapted bodyweight in LOPD patients ≥ 1 year by USFDA.

Screening for late-onset Pompe disease in Internal Medicine departments in Spain.

BACKGROUND: The screening of high-risk populations using dried blood spots (DBS) has allowed the rapid identification of patients with Pompe disease, mostly in Neurology departments. The aim of the study was to determine the prevalence of late-onset Pompe disease (LOPD) among patients not previously diagnosed or tested for this entity despite presenting possible signs or symptoms of the disease in Internal Medicine departments in Spain. METHODS: This epidemiological, observational, cross-sectional, multicenter study included a single cohort of individuals with clinical suspicion of LOPD seen at Internal Medicine departments in Spain. The diagnosis of LOPD was initially established on the basis of the result of DBS. If decreased enzyme acid-alpha-1,4-glucosidase (GAA) activity was detected in DBS, additional confirmatory diagnostic measurements were conducted, including GAA activity in lymphocytes, fibroblasts, or muscle and/or genetic testing. RESULTS: The diagnosis of LOPD was confirmed in 2 out of 322 patients (0.6%). Reasons for suspecting LOPD diagnosis were polymyositis or any type of myopathy of unknown etiology (in one patient), and asymptomatic or pauci-symptomatic hyperCKemia (in the other). The time between symptom onset and LOPD diagnosis was 2.0 and 0.0 years. Both patients were asymptomatic, with no muscle weakness. Additionally, 19.7% of the non-LOPD cases received an alternative diagnosis. CONCLUSIONS: Our study highlights the existence of a hidden population of LOPD patients in Internal Medicine departments who might benefit from early diagnosis and early initiation of potential treatments.

Disparities in late and lost: Pediatricians' role in following Pompe disease identified by newborn screening.

BACKGROUND AND OBJECTIVES: Pompe disease (PD) results from a deficiency of lysosomal acid α-glucosidase that leads to glycogen accumulation in lysosomes in multiple tissues. There are two phenotypes: infantile-onset Pompe disease (IOPD) and late-onset Pompe disease (LOPD). The objective was to evaluate the diagnostic and follow-up outcomes of children identified with PD through newborn screening (NBS) in the state of Minnesota over a 4-year period. METHODS: This study is a retrospective analysis of infants born in Minnesota between August 1, 2017, and July 31, 2021, by the Minnesota Department of Health NBS Program for Pompe disease. Newborn screening and clinical diagnostic data are summarized for all newborns with positive newborn screens for Pompe disease. RESULTS: Children with IOPD had abnormal biomarkers necessitating immediate initiation of treatment. Children with LOPD are asymptomatic to date (1.25-4.58 years) with normal biomarkers including creatine kinase, urine glucotetrasaccharides, liver function tests, and echocardiogram. The estimated birth prevalence of PD is 1:15,160. The positive predictive value for PD was 81% with a false positive rate of 1.9 per 10 positive screens. 32% of the children with LOPD were lost to follow up among which 66% were from minority ethnic groups. CONCLUSION: This emphasizes the disparity in access to health care among specific demographics, as well as the importance of a primary care provider's early involvement in educating these families. To accomplish this, and ensure equality in follow-up care, the Minnesota Pompe Disease Consortium has been formed.

Characteristics of Patients With Late-Onset Pompe Disease in France: Insights From the French Pompe Registry in 2022.

BACKGROUND AND OBJECTIVES: The French Pompe disease registry was created in 2004 for study of the natural course of the disease in patients. It rapidly became a major tool for assessing the long-term efficacy of enzyme replacement therapy (ERT) after the market release of alglucosidase-alfa. METHODS: Approximately 10 years after publication of the baseline characteristics of the 126 initial patients of the French Late-Onset Pompe Disease registry, we provide here an update of the clinical and biological features of patients included in this registry. RESULTS: We describe 210 patients followed at 31 hospital-based French neuromuscular or metabolic centers. The median age at inclusion was 48.67 ± 14.91 years. The first symptom was progressive lower limb muscle weakness, either isolated (50%) or associated with respiratory symptoms (18%), at a median age of 38 ± 14.9 years. At inclusion, 64% of the patients were able to walk independently and 14% needed a wheelchair. Positive associations were found between motor function measure, manual motor test, and 6-minute walk test (6MWT) results, and these parameters were inversely associated with the time taken to sit up from a lying position at inclusion. Seventy-two patients had been followed for at least 10 years in the registry. Thirty-three patients remained untreated a median of 12 years after symptom onset. The standard ERT dose was administered for 177 patients. DISCUSSION: This update confirms previous findings for the adult population included in the French Pompe disease registry, but with a lower clinical severity at inclusion, suggesting that this rare disease is now diagnosed earlier; thanks to greater awareness among physicians. The 6MWT remains an important method for assessing motor performance and walking ability. The French Pompe disease registry provides an exhaustive, nationwide overview of Pompe disease and can be used to assess individual and global responses to future treatments.

Long-term outcomes of very early treated infantile-onset Pompe disease with short-term steroid premedication: experiences from a nationwide newborn screening programme.

BACKGROUND: Starting enzyme replacement therapy (ERT) before severe irreversible muscular damage occurs is important in infantile-onset Pompe disease (IOPD). This long-term follow-up study demonstrates our diagnostic and treatment strategies for IOPD and compares our clinical outcomes with those of other medical centres. METHODS: In this long-term follow-up study, we analysed the outcomes of very early ERT with premedication hydrocortisone in patients with IOPD. Out of 1 228 539 infants screened between 1 January 2010 and 28 February 2021, 33 newborns had confirmed IOPD in Taipei Veterans General Hospital. Twenty-six were regularly treated and monitored at Taipei Veterans General Hospital. Echocardiographic parameters, biomarkers, IgG antibodies against alglucosidase alpha, pulmonary function variables and developmental status were all assessed regularly over an average follow-up duration of 6.18±3.14 years. We compared the long-term treatment outcomes of our patients with those of other research groups. RESULTS: The average age at ERT initiation was 9.75±3.17 days for patients with classic IOPD. The average of the latest antialglucosidase alpha IgG titre was 669.23±1159.23. All enrolled patients had normal heart sizes, motor milestones, cognitive function and pulmonary function that were near-normal to normal. Compared with patients in other studies, our patients had better outcomes in all aspects. CONCLUSION: Very early ERT using our rapid diagnostic and treatment strategy enabled our patients with IOPD to have better outcomes than patients in other medical centres.

Diagnostic Yield of Chilaiditi's Sign in Advanced-Phase Late-Onset Pompe Disease.

PURPOSE: Chilaiditi's sign (CS), hepatodiaphragmatic interposition of the intestine, was caused by morphological abnormalities such as diaphragmatic atrophy, intestinal dilation, and liver atrophy. The sign is potentially important due to associations with clinically recurrent abdominal pain or even colonic volvulus. Late-onset Pompe disease (LOPD) could have the high prevalence of CS because of widened hepatodiaphragmatic space, following diaphragmatic atrophy, and the abnormal dilation of intestine caused by glycogen accumulation in smooth muscle of intestine. Our aim was to investigate the prevalence of CS in LOPD, and to identify the risk factors of CS in LOPD patients. METHODS: Medical records of genetically confirmed patients of Pompe disease at the National Center Hospital, National Center of Neurology and Psychiatry were retrospectively reviewed. We evaluated CS using chest X-ray (CXR) and abdominal CT and assessed the prevalence of CS in LOPD patients. We also divided the patients into two groups, CS and non-CS group, and evaluated the factor associated with CS compared to clinical variables between groups. RESULTS: Three of seven (43%) were detected in CS. CS group (P5-7) and non-CS group (P1-4) were obtained. In comparison of clinical variables, the severity of atrophy in right diaphragms was significantly higher in CS than non-CS groups (p = 0.029). Also, the frequency of abnormal position of right diaphragm and liver, and abnormally dilated bowel was seen in all of CS patients, but none of non-CS patient (p = 0.029, each). CONCLUSION: In LOPD patients, the prevalence of CS was much higher of 43%, compared to healthy groups, or even in similarly respiratory muscle impaired neuromuscular diseases. The anatomically abnormal position of diaphragm and liver, atrophy and fat infiltration of diaphragms, and abnormally dilated bowel were significantly associated with CS in LOPD. We should pay more attention to CXR or abdominal CT as follow up in LOPD patients.

[Late onset Pompe disease: an analysis of 19 patients from Mexico]. / Enfermedad de Pompe de inicio tardío: análisis de una casuística de 19 pacientes mexicanos.

INTRODUCTION: Pompe disease (PD) is a rare metabolic myopathy with an ample and heterogeneous clinical spectrum, particularly late onset PD (LOPD), which is characterized by appearance at older age and slower disease progression, leading to diagnostic confirmation difficulty and delay. AIM: To describe the genotype and clinical characteristics of Mexican patients with LOPD. MATERIAL AND METHODS: Clinical information from 19 Mexican patients with LOPD confirmed with enzyme activity and GAA gene analysis was reviewed. Genetic information of our population was crossed with international genetic databases. RESULTS: Median age between onset of symptoms and diagnosis was 19 years (range 2-43) and diagnostic confirmation 36 years (range 9-52). Most frequently referred symptoms were proximal axial weakness (n = 17; 89.5%), waddling gait (n = 17; 89.5%) and hyperlordosis (n = 7; 36.8%). Sixteen patients (84.2%) were evaluated with electromyography; a myopathic pattern was reported in 11 (57.8%), but only in 5 patients (26%) paraspinal muscle evaluation was included. The most pathogenic mutations in our group were c.-32-13T>G, c.1799G>A and c.1082C>T. CONCLUSIONS: Similar to other international publications, LOPD in Mexico is clinically heterogeneous; patients may delay years before diagnosis is established. Axial and proximal weakness is the most frequent clinical feature; thus, electromyography with paraspinal muscle evaluation is essential. Except for one, the mutations found in our patients have been previously reported in PD genetic databases.

TITLE: Enfermedad de Pompe de inicio tardío: análisis de una casuística de 19 pacientes mexicanos.Introducción. La enfermedad de Pompe es una miopatía metabólica rara con espectro clínico heterogéneo, especialmente la de inicio tardío, cuya sintomatología es de progresión más lenta y representa un gran reto diagnóstico. Objetivo. Describir el genotipo y las características clínicas de pacientes mexicanos con Pompe de inicio tardío (LOPD). Material y métodos. Se incluyó a 19 pacientes mexicanos con LOPD confirmada mediante actividad enzimática y estudio molecular del gen GAA. Se evaluaron datos clínicos y se revisaron las mutaciones en bases de datos genómicas. Resultados. La mediana de edad de inicio de los síntomas fue de 19 años (rango: 2-43 años), y la edad de diagnóstico, de 36 años (rango: 9-52 años). Los síntomas más frecuentes fueron debilidad axial y proximal (n = 17; 89,5%), marcha basculante (n = 17; 89,5%) e hiperlordosis (n = 7; 36,8%). A 16 pacientes (84,2%) se les realizó electromiografía; 11 (57,8%) describieron patrón miopático y sólo en cinco pacientes (26%) se incluyó la valoración de los músculos paraespinales. Las variantes patogénicas más frecuentes en nuestra casuística fueron c.-32-13T>G, c.1799G>A y c.1082C>T. Conclusiones. Parecido a lo comunicado en publicaciones internacionales, la LOPD en México es clínicamente heterogénea; los pacientes pueden tardar años en llegar al diagnóstico. La debilidad muscular axial y proximal es el dato clínico más frecuente, por lo que la electromiografía debe incluir valoración de los músculos paraespinales. A excepción de una, las mutaciones encontradas en nuestra serie de casos se encuentran previamente descritas en las bases de datos de enfermedad de Pompe.

Prevalence of lower urinary tract symptoms in children with early-treated infantile-onset Pompe disease: A single-centre cross-sectional study.

AIM: To evaluate lower urinary tract symptoms (LUTS) in children with infantile-onset Pompe disease (IOPD) who received early treatment. METHODS: Pompe disease (PD), or glycogen storage disease II is a rare autosomal recessive lysosomal storage disease that affects multiple organ systems. To our knowledge, only one study has focused on the relationship between LUTS and incontinence in children with PD. This cross-sectional study was conducted from August 2019 through March 2021 and children with IOPD, who had received early and regular enzyme replacement therapy, were enrolled. Participants or their parents completed the Dysfunctional Voiding Scoring System (DVSS) questionnaire. All children underwent uroflowmetry and postvoid residual urine measurements. Fourteen children (age, 4-9 years) with IOPD were enrolled. RESULTS: Ten patients (71.4%) had abnormal uroflow curves. In addition, results of the DVSS revealed that approximately half (42.9%) of our IOPD patients had voiding dysfunction, with urinary incontinence as the most common symptom (64.3%, 9/14). No significant correlations were found between LUTS and uroflow curves in children with IOPD. CONCLUSIONS: The frequency of LUTS and lower urinary tract dysfunction noted on uroflowmetry should encourage pediatricians to actively identify IOPD patients with LUTS, regardless of the timing and frequency of their treatments, and refer them to a urologist for further evaluation and appropriate treatment.

Phenotypic implications of pathogenic variant types in Pompe disease.

Newborn screening and therapies for Pompe disease (glycogen storage disease type II, acid maltase deficiency) will continue to expand in the future. It is thus important to determine whether enzyme activity or type of pathogenic genetic variant in GAA can best predict phenotypic severity, particularly the presence of infantile-onset Pompe disease (IOPD) versus late-onset Pompe disease (LOPD). We performed a retrospective analysis of 23 participants with genetically-confirmed cases of Pompe disease. The following data were collected: clinical details including presence or absence of cardiomyopathy, enzyme activity levels, and features of GAA variants including exon versus intron location and splice site versus non-splice site. Several combinations of GAA variant types for individual participants had significant associations with disease subtype, cardiomyopathy, age at diagnosis, gross motor function scale (GMFS), and stability of body weight. The presence of at least one splice site variant (c.546 G > C/p.T182 = , c.1076-22 T > G, c.2646 + 2 T > A, and the classic c.-32-13T > G variant) was associated with LOPD, while the presence of non-splice site variants on both alleles was associated with IOPD. Enzyme activity levels in isolation were not sufficient to predict disease subtype or other major clinical features. To extend the findings of prior studies, we found that multiple types of splice site variants beyond the classic c.-32-13T > G variant are often associated with a milder phenotype. Enzyme activity levels continue to have utility for supporting the diagnosis when the genetic variants are ambiguous. It is important for newly diagnosed patients with Pompe disease to have complete genetic, cardiac, and neurological evaluations.

[GAA gene variants and genotype-phenotype correlations in patients with glycogen storage disease type â ¡].

Objectives: To explore the GAA varient spectrum and the genotype-phenotype correlations in patients with glycogen storage disease type Ⅱ (Pompe disease, PD), as well as to estimate the disease incidence based on carrier rate of GAA varients in Guangzhou population. Methods: A total of 57 PD cases were retrospectively enrolled at Guangzhou Women and Children's Medical Center from January 1, 2010 to May 31, 2020. All patients presented symptoms before the age of 18 years. Each diagnosis was further confirmed by GAA enzyme activity and GAA variants. The carrier rate of GAA varients was calculated based on variants detected by whole exon sequencing among 2 395 healthy children in Guangzhou. Results: Among the 57 PD patients (including male 26, female 31),twenty-eight patients with infantile onset PD (IOPD) presented with progressive general muscle weakness and cardiomyopathy. The mean ages of symptom onset and diagnosis were (2.5±1.4) and (5.0±3.0) months, respectively. Twenty-six cases died in the first year after birth.Twenty-three patients with late onset PD (LOPD) presented with progressive muscle weakness. Seven of them had respiratory failure at diagnosis. The mean ages of symptom onset and diagnosis were (12.0±5.0) and (17.0±7.5) years, respectively. Six children with atypical IOPD showed motor delay, muscle weakness and cardiomyopathy. Their diagnosis was confirmed at 2.5-7.0 years of age. Among the 57 patients, 47 different variants were identified in the GAA gene. Three variants: c.797C>T, c.1109G>A and c.1757C>T were novel. c.1935C>A (25/114, 21.9%) and c.2238G>C (15/114, 13.2%) were the most common variants, detected in 57.1% of IOPD and 65.2% (15/23) of LOPD patients, respectively. Among the 28 IOPD patients, 26 cases (92.9%) carried at least one missense variant which indicated positive cross-reactive immunologic material (CRIM). The carrier rate of pathogenic variants in GAA gene among healthy children was 24/2 395. The estimated incidence of PD in this population is about 1/40 000. The frequencies of pseudodeficiency variants c.1726G>A and c.2065G>A homozygotes were 26.3% (15/57) and 35.1% (20/57) in PD patients, which were significantly higher than those (1.7% (40/2 395) and 3.9% (94/2 395)) in healthy children (χ²=151.2, 121.9; both P<0.01). Conclusions: PD presents as a spectrum, some as atypical IOPD. The c.1935C>A and c.2238G>C are common variants, correlated with IOPD and LOPD respectively. The c.796C>T and c.1082C>T are usually found in atypical IOPD. The majority of IOPD patients is predicted to be CRIM positive. The estimated incidence of PD is about 1/40 000.

Standardized nursing management of enzyme replacement therapy for late-onset Pompe disease.

ABSTRACT: Pompe disease or glycogen storage disease type II is a rare autosomal recessive disorder caused by a deficiency of the lysosomal enzyme a-glucosidase. Although enzyme replacement therapy (ERT) with 2 weekly intervals following was considered an effective treatment for Pompe disease in 2006, few patients can afford to receive treatment in China because of the high cost. This study aimed to examine the standard management of enzyme replacement therapy for late-onset Pompe disease among patients over the age of 14 years from a nursing perspective in order to assess operating procedures. ERT injection fluid dispensing and infusion procedures using different methods were analyzed and compared in 3 patients with advanced Pompe disease for forming standard operation procedures. In addition, the impact of different methods on time consumption was analyzed by 1-way analysis of variance. There were significant differences in time consumption between different dispensing and infusion methods. The time of dispensing and infusing the injection fluids using the cooperative method was 15.97 minutes shorter than that using the conventional method (95% CI: 4.51-27.43, P = .012); the time using the modified method was 20.93 minutes shorter than that using the conventional method (95% CI: 9.47-32.39, P = .012); and there was no significant difference between the cooperative and modified methods (P = .431). Enzyme replacement therapy entails frequent treatment and strict nursing requirements related to the intravenous infusion process. In this context, a standard operating procedure can be used to control nursing times and labor costs effectively while ensuring a safe and effective infusion process.

Potential patient screening for late-onset Pompe disease in suspected sleep apnea: a rationale and study design for a Prospective Multicenter Observational Cohort Study in Japan (PSSAP-J Study).

BACKGROUND: Pompe disease is an autosomal recessive disorder caused by deficiency of the acid α-glucosidase (GAA) enzyme. GAA deficiency induces progressive glycogen accumulation which leads to weakness of the respiratory muscle including the diaphragm. Pompe disease is one of the few myopathies, for which an established therapy is available. Thus, earlier detection of potential late-onset Pompe disease (LOPD) and earlier intervention would have a significant clinical impact. PURPOSE: Our hypothesis is that sleep problems including sleep disordered breathing (SDB) and clinical symptoms may indicate an early stage of LOPD since decreased respiratory muscle activity generally first presents during sleep. Thus, the aims of this prospective, multicenter observational cohort study in Japan (PSSAP-J) are to demonstrate a higher prevalence of LOPD in a sleep lab-based population (primary outcome), and to identify predictive factors for LOPD from findings in diagnostic polysomnography (PSG) and clinical symptoms (secondary outcomes). METHODS: The study design is a prospective multicenter observational cohort study. Consecutive patients who present to sleep labs due to suspected SDB for an overnight PSG will be enrolled. All patients will be measured for creatine kinase, GAA activity, and if necessary, genetic analysis of GAA. Furthermore, chest X-ray, pulmonary function test, and arterial blood gas analysis will be collected. Then, prevalence and specific findings of LOPD will be assessed. RESULT: Congenital myopathy shows a shift from slow-deep to rapid-shallow breathing during transition from wakefulness to sleep accompanying a symptom of waking with gasping (actual further results are pending). DISCUSSION: The distribution in respiratory physiology between during wakefulness and sleep specific to LOPD may provide insights into early-stage detection. CLINICAL TRIAL REGISTRATION NUMBER: UMIN000039191, UMIN Clinical Trials Registry ( http://www.umin.ac.jp/ctr ).

Health and economic outcomes of newborn screening for infantile-onset Pompe disease.

PURPOSE: To estimate health and economic outcomes associated with newborn screening (NBS) for infantile-onset Pompe disease in the United States. METHODS: A decision analytic microsimulation model simulated health and economic outcomes of a birth cohort of 4 million children in the United States. Universal NBS and treatment was compared with clinical identification and treatment of infantile-onset Pompe disease. Main outcomes were projected cases identified, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) over the life course. RESULTS: Universal NBS for Pompe disease and confirmatory testing was estimated to cost an additional $26 million annually. Additional medication costs associated with earlier treatment initiation were $181 million; however, $8 million in medical care costs for other services were averted due to delayed disease progression. Infants with screened and treated infantile-onset Pompe disease experienced an average lifetime increase of 11.66 QALYs compared with clinical detection. The ICER was $379,000/QALY from a societal perspective and $408,000/QALY from the health-care perspective. Results were sensitive to the cost of enzyme replacement therapy. CONCLUSION: Newborn screening for Pompe disease results in substantial health gains for individuals with infantile-onset Pompe disease, but with additional costs.

NGS-based expanded carrier screening for genetic disorders in North Indian population reveals unexpected results - a pilot study.

BACKGROUND: To determine the carrier frequency and pathogenic variants of common genetic disorders in the north Indian population by using next generation sequencing (NGS). METHODS: After pre-test counselling, 200 unrelated individuals (including 88 couples) were screened for pathogenic variants in 88 genes by NGS technology. The variants were classified as per American College of Medical Genetics criteria. Pathogenic and likely pathogenic variants were subjected to thorough literature-based curation in addition to the regular filters. Variants of unknown significance were not reported. Individuals were counselled explaining the implications of the results, and cascade screening was advised when necessary. RESULTS: Of the 200 participants, 52 (26%) were found to be carrier of one or more disorders. Twelve individuals were identified to be carriers for congenital deafness, giving a carrier frequency of one in 17 for one of the four genes tested (SLC26A4, GJB2, TMPRSS3 and TMC1 in decreasing order). Nine individuals were observed to be carriers for cystic fibrosis, with a frequency of one in 22. Three individuals were detected to be carriers for Pompe disease (frequency one in 67). None of the 88 couples screened were found to be carriers for the same disorder. The pathogenic variants observed in many disorders (such as deafness, cystic fibrosis, Pompe disease, Canavan disease, primary hyperoxaluria, junctional epidermolysis bullosa, galactosemia, medium chain acyl CoA deficiency etc.) were different from those commonly observed in the West. CONCLUSION: A higher carrier frequency for genetic deafness, cystic fibrosis and Pompe disease was unexpected, and contrary to the generally held view about their prevalence in Asian Indians. In spite of the small sample size, this study would suggest that population-based carrier screening panels for India would differ from those in the West, and need to be selected with due care. Testing should comprise the study of all the coding exons with its boundaries in the genes through NGS, as all the variants are not well characterized. Only study of entire coding regions in the genes will detect carriers with adequate efficiency, in order to reduce the burden of genetic disorders in India and other resource poor countries.

Late-onset Pompe disease (LOPD) in Belgium: clinical characteristics and outcome measures.

BACKGROUND: Late-onset Pompe disease (LOPD) is a rare, hereditary, progressive disorder that is usually characterized by limb-girdle muscle weakness and/or respiratory insufficiency. LOPD is caused by mutations in the acid alpha-glucosidase (GAA) gene and treated with enzyme replacement therapy (ERT). METHODS: We studied the clinical, brain imaging, and genetic features of the Belgian cohort of late-onset Pompe disease patients (N = 52), and explored the sensitivity of different outcome measures, during a longitudinal period of 7 years (2010-2017), including the activity limitations ActivLim score, 6 min walking distance (6MWD), 10 m walk test (10MWT), MRC sum score, and forced vital capacity (FVC) sitting/supine. RESULTS: In Belgium, we calculated an LOPD prevalence of 3.9 per million. Mean age at onset of 52 LOPD patients was 28.9 years (SD: 15.8 y), ranging from 7 months to 68 years. Seventy-five percent (N = 39) of the patients initially presented with limb-girdle weakness, whereas in 13% (N = 7) respiratory symptoms were the only initial symptom. Non-invasive ventilation (NIV) was started in 37% (N = 19), at a mean age of 49.5 years (SD: 11.9 y), with a mean duration of 15 years (SD: 10.2 y) after symptom onset. Brain imaging revealed abnormalities in 25% (N = 8) of the patients, with the presence of small cerebral aneurysm(s) in two patients and a vertebrobasilar dolichoectasia in another two. Mean diagnostic delay was 12.9 years. All patients were compound heterozygotes with the most prevalent mutation being c.-32-13 T > G in 96%. We identified two novel mutations in GAA: c.1610_1611delA and c.186dup11. For the 6MWD, MRC sum score, FVC sitting and FVC supine, we measured a significant decrease over time (p = 0.0002, p = 0.0001, p = 0.0077, p = 0.0151), which was not revealed with the ActivLim score and 10MWT (p > 0.05). CONCLUSIONS: Awareness on LOPD should even be further increased because of the long diagnostic delay. The 6MWD, but not the ActivLim score, is a sensitive outcome measure to follow up LOPD patients.

Generalized glycogenosis in Brahman-derived breeds: diagnosis and prevalence in Argentina.

Generalized glycogenosis is a lethal autosomal recessive disease caused by a deficient activity of the acidic 1,4-α-glucosidase enzyme and characterized by an accumulation of glycogen within lysosomes. Three mutations in the GAA gene causing bovine generalized glycogenosis have been identified in two cattle breeds, Brahman and Shorthorn. The objective of this study was to evaluate the prevalence of carriers of the E7 mutation in the GAA gene in Argentinean Brahman-derived herds. A total of 930 Braford, 94 Brangus, and 8 Brahman samples were analyzed. The genotyping was done by polymerase chain reaction and restriction fragment length polymorphism (PCR/RFLP). We found that 12.02% (95% CI 12.00-12.04) of the total number of samples received were heterozygous (i.e., carriers) for the E7 mutation, while 12.58% (95% CI 12.56-12.60) of the Braford, 6.38% (95% CI 6.26-6.51) of the Brangus, and 12.50% (95% CI 9.82-15.18) of the Brahman samples were carriers of this loss-of-function allele. Neither breed nor sex were significantly associated to the presence of the mutation. The prevalence informed in this study is similar to the average prevalence reported for Australian Brahmans. The finding of heterozygous animals suggests that breeders and insemination centers should continue screening their herds to minimize the dissemination of this deleterious allele.

Pre/post effectiveness evaluation of updated additional risk minimisation measures for an orphan disease: Myozyme (alglucosidase alfa) Safety Information Packet.

BACKGROUND: The alglucosidase alfa (Myozyme®) Safety Information Packet ("previous SIP") was updated to improve readability and content ("updated SIP"). We compared the previous and updated SIPs. METHODS: A two-wave pre-post multicountry survey was conducted among health care professionals (HCPs) who prescribed or monitored patients on alglucosidase alfa in the largest European Union ("EU5") countries and Poland. Wave (W) 2 started 15 months after completion of W1 and the implementation of the updated SIP. Changes between the waves were analysed. RESULTS: Forty-six HCPs (34 physicians/12 nurses) participated in W1 and 52 in W2 (42 physicians/10 nurses); 22 participated in both waves. Nonsignificant differences were observed between waves 1 and 2 for awareness (75.6% in W1 and 82.4% in W2) and receipt (77.7% in W1 and 74.5% in W2) of the SIP, reading (88.6% in W1 and 89.5% in W2) and usage (88.2% in W1 and 89.5% in W2) among receivers of the SIP, or the overall knowledge about immunological testing (61.1% in W1 vs 55.1% in W2). Frequency of performance of immunological testing was significantly higher in W2 than in W1 (50.3% vs 34.4%; P = .024) with a tendency for increases in the appropriate performance of all types of testing in W2. CONCLUSIONS: Both versions of the SIP showed relatively high awareness, receipt, reading, and usage, with an overall trend for most measures to improve numerically in W2. The updated SIP did not require further changes.