The importance of early diagnosis and views on newborn screening in metachromatic leukodystrophy: results of a Caregiver Survey in the UK and Republic of Ireland

Latent profiles and predictors of barriers to care in Swiss children and adolescents with rare diseases

OBJECTIVE

Children and adolescents with rare diseases face significant barriers when accessing healthcare. We aimed to assess and predict these barriers and investigate associations with health-related quality of life (HRQoL).

METHOD

We conducted a cross-sectional survey of Swiss parents (N = 189) of children with rare diseases including the Barriers to Care Questionnaire (BCQ), containing six barriers and the Pediatric Quality of Life Inventory (PedsQL). Latent profile analysis (LPA) was used to uncover distinct classes, which were compared using chi-square tests and Mann-Whitney U tests. Relevant medical and sociodemographic class predictors were identified using Elastic Net regression, followed by regression analysis to investigate their role in predicting barriers to care and examine the effects of these classes on HRQoL.

RESULTS

Two distinct groups were identified, a higher barriers class (59%) and a lower barriers class (41%). In the higher barriers class, participants showed elevated scores across all subscales and specifically on pragmatics and expectations. More barriers to care were linked to a nonstable disease course (OR = 2.27, p = .002) and a diagnosis after the age of 3 months (OR = 2.17, p = .006). Individuals in the higher barriers class exhibited more psychological comorbidities (p = .044), congenital malformations/deformations/chromosomal abnormalities (p=.042), and medical misdiagnoses (p = .006). Children in the higher barriers class had significantly lower PedsQL scores compared to the lower barriers class (p <.05).

CONCLUSION

This study highlights the need for comprehensive assessment of barriers to pediatric care in rare diseases, offering potential entry points for targeted interventions.

Experiences of patients with metachromatic leukodystrophy, adrenoleukodystrophy, or Krabbe disease and the experiences of their family members: a qualitative systematic review

OBJECTIVE

This review aimed to synthesize the experiences of patients with metachromatic leukodystrophy, adrenoleukodystrophy, or Krabbe disease and the experiences of their families.

INTRODUCTION

Leukodystrophies are metabolic diseases caused by genetic mutations. There are multiple forms of the disease, varying in age of onset and symptoms. The progression of leukodystrophies worsens central nervous system symptoms and significantly affects the lives of patients and their families.

INCLUSION CRITERIA

Qualitative studies on the experiences of patients with leukodystrophies and their family members were included. These experiences included treatments such as enzyme replacement therapy and hematopoietic stem cell transplantation; effects of tracheostomy and gastrostomy; burdens on the family, coordinating care within the health care system, and family planning due to genetic disorders. This review considered studies in any setting.

METHODS

MEDLINE (Ovid), CINAHL Plus (EBSCOhost), APA PsycINFO (EBSCOhost), Scopus, and MedNar databases were searched on November 18, 2022. Study selection, critical appraisal, data extraction, and data synthesis were conducted in accordance with the JBI methodology for systematic reviews of qualitative evidence, and synthesized findings were evaluated according to the ConQual approach.

RESULTS

Eleven studies were eligible for synthesis, and 45 findings were extracted corresponding with participants' voices. Of these findings, 40 were unequivocal and 5 were credible. The diseases in the included studies were metachromatic leukodystrophy and adrenoleukodystrophy; no studies were identified for patients with Krabbe disease and their families. These findings were grouped into 11 categories and integrated into 3 synthesized findings, including i) providing care by family members and health care providers as physical symptoms progress, which relates to the effects of the characteristics of progressive leukodystrophies; ii) building medical teamwork to provide appropriate support services, comprising categories related to the challenges experienced with the health care system for patients with leukodystrophy and their families; and iii) coordinating family functions to accept and cope with the disease, which included categories related to family psychological difficulties and role divisions within the family. According to the ConQual criteria, the second synthesized finding had a low confidence level, and the first and third synthesized findings had a very low confidence level.

CONCLUSIONS

The synthesized findings of this review provide evidence on the experiences of patients with metachromatic leukodystrophy or adrenoleukodystrophy and their families. These findings indicate that there are challenges in managing a patient's physical condition and coordinating the health care system and family functions.

REVIEW REGISTRATION

PROSPERO CRD42022318805.

SUPPLEMENTAL DIGITAL CONTENT

A Japanese-language version of the abstract of this review is available [ http://links.lww.com/SRX/A49 ].

Current Status of Newborn Bloodspot Screening Worldwide 2024: A Comprehensive Review of Recent Activities (2020-2023)

Newborn bloodspot screening (NBS) began in the early 1960s based on the work of Dr. Robert "Bob" Guthrie in Buffalo, NY, USA. His development of a screening test for phenylketonuria on blood absorbed onto a special filter paper and transported to a remote testing laboratory began it all. Expansion of NBS to large numbers of asymptomatic congenital conditions flourishes in many settings while it has not yet been realized in others. The need for NBS as an efficient and effective public health prevention strategy that contributes to lowered morbidity and mortality wherever it is sustained is well known in the medical field but not necessarily by political policy makers. Acknowledging the value of national NBS reports published in 2007, the authors collaborated to create a worldwide NBS update in 2015. In a continuing attempt to review the progress of NBS globally, and to move towards a more harmonized and equitable screening system, we have updated our 2015 report with information available at the beginning of 2024. Reports on sub-Saharan Africa and the Caribbean, missing in 2015, have been included. Tables popular in the previous report have been updated with an eye towards harmonized comparisons. To emphasize areas needing attention globally, we have used regional tables containing similar listings of conditions screened, numbers of screening laboratories, and time at which specimen collection is recommended. Discussions are limited to bloodspot screening.

The economic impact of living with a rare disease for children and their families: a scoping review protocol

Background

Rare diseases are an often chronic, progressive and life-limiting group of conditions affecting more than 30 million people in Europe. These diseases are associated with significant direct and indirect costs to a spectrum of stakeholders, ranging from individuals and their families to society overall. Further quantitative research on the economic cost for children and their families living with a rare disease is required as there is little known on this topic. This scoping review aims to document the extent and type of evidence on the economic impacts of living with a rare disease for children and their families.

Methods

This scoping review will follow the PRISMA-ScR and Joanna Briggs Institute guidelines and follow the six-stage methodology for scoping reviews: (1) identifying the research question, (2) identifying relevant studies, (3) study selection, (4) charting the data, (5) collating, summarising and reporting results and (6) knowledge user consultation. Key inclusion criteria have been developed according to the Population-Concept-Context (PCC) framework. The databases EconLit, ABI/Inform, MEDLINE, PubMed, CINAHL, and Scopus will be searched for possible articles for inclusion. Two independent reviewers will screen titles and abstracts of potential articles using a dual review process to ensure all relevant studies are included. All included articles will be assessed using a validated quality appraisal tool. A panel of patient and public involvement representatives experiencing rare diseases and knowledge users will validate the review results.

Conclusions

This scoping review will map the current literature on the economic impact of paediatric rare diseases to understand how these impacts affect children living with rare diseases and their families. This evidence has the potential to influence policy and future research in this area and will support further research on the economic impact of rare diseases on families.

The natural history and burden of illness of metachromatic leukodystrophy: a systematic literature review

BACKGROUND

Metachromatic leukodystrophy (MLD; OMIM 250100 and 249900) is a rare lysosomal storage disease caused by deficient arylsulfatase A activity, leading to accumulation of sulfatides in the nervous system. This systematic literature review aimed to explore the effect of MLD on the lives of patients.

METHODS

The Ovid platform was used to search Embase, MEDLINE, and the Cochrane Library for articles related to the natural history, clinical outcomes, and burden of illness of MLD; congress and hand searches were performed using 'metachromatic leukodystrophy' as a keyword. Of the 531 publications identified, 120 were included for data extraction following screening. A subset of findings from studies relating to MLD natural history and burden of illness (n = 108) are presented here.

RESULTS

The mean age at symptom onset was generally 16-18 months for late-infantile MLD and 6-10 years for juvenile MLD. Age at diagnosis and time to diagnosis varied widely. Typically, patients with late-infantile MLD presented predominantly with motor symptoms and developmental delay; patients with juvenile MLD presented with motor, cognitive, and behavioral symptoms; and patients with adult MLD presented with cognitive symptoms and psychiatric and mood disorders. Patients with late-infantile MLD had more rapid decline of motor function over time and lower survival than patients with juvenile MLD. Commonly reported comorbidities/complications included ataxia, epilepsy, gallbladder abnormalities, incontinence, neuropathy, and seizures.

CONCLUSIONS

Epidemiology of MLD by geographic regions, quantitative cognitive data, data on the differences between early- and late-juvenile MLD, and humanistic or economic outcomes were limited. Further studies on clinical, humanistic (i.e., quality of life), and economic outcomes are needed to help inform healthcare decisions for patients with MLD.

Impact on physical, social, and family functioning of patients with metachromatic leukodystrophy and their family members in Japan: A qualitative study

Metachromatic leukodystrophy is a rare autosomal recessive disease. There are three forms of this disease, all of which result in cognitive and motor dysfunctions. Although enzyme replacement and gene therapies have been developed, they are not expected to be effective in patients with advanced diseases. Therefore, it is important to focus on treatment effects and patients' quality of life; however, qualitative findings on the experiences of patients and their families have not been adequately reported. Interviews were conducted with the family members of patients with metachromatic leukodystrophy in Japan. Verbatim transcripts were analyzed using a qualitative content analysis approach. We interviewed the mothers of five patients. Verbatim interview transcripts were classified into 81 codes. The codes were then aggregated into 15 categories and 3 themes: challenges of life for the patients, challenges in the healthcare system, and challenges of family function. Disease progression greatly affects patients' lives. Moreover, social systems supporting patients and their families are inadequate, especially as the disease progresses. Family members face life restrictions and role changes because of the patient's diagnosis. Patients with metachromatic leukodystrophy and their families require comprehensive support.

The burden of disease in metachromatic leukodystrophy: results of a caregiver survey in the UK and Republic of Ireland

BACKGROUND

Metachromatic Leukodystrophy (MLD) is a rare, autosomal recessive lysosomal storage disease characterised by the progressive loss of motor function and severe decline in cognitive function. Limited information is available on the burden MLD places on patients and their families and the medical and social support these patients need. Three UK-based MLD patient organisations commissioned an online survey, and follow-up semi-structured interviews to describe and quantify these burdens across MLD subtypes, stage of disease (including end of life) and treatment status (untreated, gene therapy or hematopoietic stem cell transplant [HSCT]).

RESULTS

A total of 24 patients were included in the study: thirteen late infantile (LI), six early juvenile (EJ), two late juvenile (LJ) and three adult onset (AO). Six patients had received gene therapy and one had received an HSCT. MLD patients receiving no disease modifying treatment bore a high symptom burden: 94% were wheelchair dependent, 88% required tube feeding, 88% were incontinent, 82% had lost their speech and all the children were either unable to attend education or needed specialist provision. Patients were reliant on numerous medical interventions and assistive equipment. All early-onset patients (LI and EJ) were wheelchair dependent, and tube fed, with all EJ patients having lost all speech. The caregiving responsibilities of parents impacted their employment, finances, relationships and health. Patients treated with gene therapy or HSCT were more mobile and were able to eat normally and two thirds of the children were able to attend mainstream school.

CONCLUSIONS

The impact of illness that patients and their caregivers faced was extensive, and the level of care, amount of medication, number of hospital visits and educational support required were substantial. Financial constraints often brought about by inability to work also placed considerable strain on families. The study increases understanding of the burden of MLD on patients and their families, and the level of unmet need in the treatment of the disease.

Sphingolipidoses in Morocco: Chemical profiling for an affordable and rapid diagnosis strategy

Sphingolipidoses are a group of metabolic diseases in which lysosomal hydrolases dysfunction disrupt normal sphingolipids' metabolism, leading to excess accumulation in cellular compartments and excretion in urine. These pathologies represent a significant burden among Moroccan population, for which an easy access to enzymatic assays and genetic tests is not guaranteed. Parallel analytical methods thus have to be developed for preliminary screening. In this study, 107 patients were addressed to the metabolic platform of the Marrakesh Faculty of Medicine for diagnosis confirmation. Thin-Layer Chromatography was used as a first step to perform chemical profiling of the patients' urinary lipids, allowing 36% of the patients to be efficiently oriented towards the adequate enzymatic assay. UPLC-MS/MS analyses of urinary sulfatides excreted in urines patient had been used to control the reliability of TLC analysis and to obtain more accurate information related to the sulfatides isoforms. This analytical process combining TLC with UPLC-MS/MS has enabled rapid and appropriate patient management in a reduced time and with reduced resources.

A retrospective cohort study of Libmeldy (atidarsagene autotemcel) for MLD: What we have accomplished and what opportunities lie ahead

Metachromatic leukodystrophy (MLD) results from ARSA gene mutations. Affected individuals meet early milestones before neurological deterioration and early death. Atidarsagene autotemcel (arsa-cel), an autologous haematopoietic stem cell gene therapy (HSC-GT) product, has demonstrated sustained clinical benefits in MLD. Arsa-cel was approved for NHS treatment in February 2022 for asymptomatic late infantile or early juvenile disease, or early symptomatic early juvenile MLD. We evaluate the impact of this approval in the largest real-world dataset of MLD HSC-GT. Hospital records were reviewed for all patients referred for NHS treatment following arsa-cel approval. Information was gathered about disease phenotype, presentation, eligibility, and affected siblings. In the year following NHS approval, 17 UK MLD patients were referred for treatment. Four patients met eligibility criteria and have been treated, including 1 infant who weighed 5 kg at leukapheresis. Eleven patients failed screening: 10 symptomatic patients with late infantile disease and 1 with early juvenile disease and cognitive decline. Two further patients with later onset subtypes did not meet the approval criteria. Three out of four treated patients were diagnosed by screening after MLD was diagnosed in a symptomatic older sibling. The success of HSC-GT for MLD has heralded a new era of hope for families affected by this devastating disease, yet currently, most patients are ineligible for treatment at diagnosis. The feasibility of apheresis in infants and the availability of a licenced, effective HSC-GT product highlights the urgent need for newborn screening to ensure that patients can be diagnosed and treated before symptom onset.

An in silico approach to identify early damage biomarker candidates in metachromatic leukodystrophy

Metachromatic leukodystrophy (MLD) is a rare, autosomal recessive lysosomal storage disease. Deficient activity of arylsulfatase A causes sulfatides to accumulate in cells of different tissues, including those in the central and peripheral nervous systems, leading to progressive demyelination and neurodegeneration. Although there is some association between specific arylsulfatase A alleles and disease severity, genotype-phenotype correlations are not fully understood. We aimed to identify biomarker candidates of early tissue damage in MLD using a modeling approach based on systems biology. A review of the literature was performed in an initial disease characterization step, allowing identification of pathophysiological processes involved in MLD and proteins relating to these processes. Three mathematical models were generated to simulate different stages of MLD at the molecular level: an early pro-inflammatory stage model (including only processes considered to be active in the early stages of disease), a pre-demyelination stage model (including additional processes that are active after some disease progression), and a demyelination stage model (in which all pathophysiological processes are active). The models evaluated 3457 proteins of interest, individually and by pairs through data mining techniques, applying five filters to prioritize biomarkers that could differentiate between the models. Sixteen potential biomarkers were identified, including effectors relating to mitochondrial dysfunction, remyelination, and neurodegeneration. The findings were corroborated in a gene expression data set from T lymphocytes of patients with MLD; all candidates formed combinations that were able to distinguish patients with MLD from controls, and all but one candidate distinguished late-infantile MLD from juvenile MLD as part of a combinatorial biomarker pair. In particular, pro-neuregulin-1 appeared as differential on all comparisons (patients with MLD vs controls and within clinical subtypes); casein kinase II subunit alpha was detected as a potential individual marker within clinical subtypes. These findings provide a panel of biomarker candidates suitable for experimental validation and highlight the utility of mathematical models to identify biomarker candidates of early tissue damage in MLD with a high degree of accuracy and sensitivity.

Evidence Synthesis of Gene Therapy and Gene Editing from Different Disorders-Implications for Individuals with Rett Syndrome: A Systematic Review

This systematic review and thematic analysis critically evaluated gene therapy trials in amyotrophic lateral sclerosis, haemoglobinopathies, immunodeficiencies, leukodystrophies, lysosomal storage disorders and retinal dystrophies and extrapolated the key clinical findings to individuals with Rett syndrome (RTT). The PRISMA guidelines were used to search six databases during the last decade, followed by a thematic analysis to identify the emerging themes. Thematic analysis across the different disorders revealed four themes: (I) Therapeutic time window of gene therapy; (II) Administration and dosing strategies for gene therapy; (III) Methods of gene therapeutics and (IV) Future areas of clinical interest. Our synthesis of information has further enriched the current clinical evidence base and can assist in optimising gene therapy and gene editing studies in individuals with RTT, but it would also benefit when applied to other disorders. The findings suggest that gene therapies have better outcomes when the brain is not the primary target. Across different disorders, early intervention appears to be more critical, and targeting the pre-symptomatic stage might prevent symptom pathology. Intervention at later stages of disease progression may benefit by helping to clinically stabilise patients and preventing disease-related symptoms from worsening. If gene therapy or editing has the desired outcome, older patients would need concerted rehabilitation efforts to reverse their impairments. The timing of intervention and the administration route would be critical parameters for successful outcomes of gene therapy/editing trials in individuals with RTT. Current approaches also need to overcome the challenges of MeCP2 dosing, genotoxicity, transduction efficiencies and biodistribution.