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Molecular Genetics and Metabolism Dec 2023X-linked adrenoleukodystrophy (XALD) is the most common leukodystrophy. It has an estimated incidence of around 1/17.000, and a variable phenotype. Following the passage... (Review)
Review
X-linked adrenoleukodystrophy (XALD) is the most common leukodystrophy. It has an estimated incidence of around 1/17.000, and a variable phenotype. Following the passage of Aidens Law, New York became the first state to implement a newborn screening for XALD in 2013. Since then, 38 American states, Taiwan, and the Netherlands have included XALD in their NBS program, and Japan and Italy have ongoing pilot studies. Screening for XALD allows for early, potentially lifesaving treatment of adrenal insufficiency and cerebral demyelination but is also a complex subject, due to our limited understanding of the natural history and lack of prognostic biomarkers. Screening protocols and algorithms vary between countries and states, and results and experiences gained so far are important for the future implementation of XALD NBS in other countries. In this review, we have examined the algorithms, methodologies, and outcomes used, as well as how common challenges are addressed in countries/states that have experience using NBS for XALD. We identified 14 peer-reviewed reports on NBS for XALD. All studies presented methods for detecting XALD at birth by NBS using a combination of mass spectrometry and ABCD1 gene sequencing. This has allowed for early surveillance of presymptomatic XALD patients, and the possibility for early detection and timely treatment of XALD manifestations. Obstacles to NBS for XALD include how to deal with variants of unknown significance, whether to screen females, and the ethical concerns of an NBS for a disease where we have limited understanding of natural history and phenotype/genotype correlation.
Topics: Infant, Newborn; Female; Humans; Adrenoleukodystrophy; Neonatal Screening; Adrenal Insufficiency; New York; Genetic Association Studies
PubMed: 37979237
DOI: 10.1016/j.ymgme.2023.107734 -
Orphanet Journal of Rare Diseases Nov 2023Zellweger spectrum disorders (ZSD) and X-linked adrenoleukodystrophy (X-ALD) are inherited metabolic diseases characterized by dysfunction of peroxisomes, that are...
BACKGROUND
Zellweger spectrum disorders (ZSD) and X-linked adrenoleukodystrophy (X-ALD) are inherited metabolic diseases characterized by dysfunction of peroxisomes, that are essential for lipid metabolism and redox balance. Oxidative stress has been reported to have a significant role in the pathogenesis of neurodegenerative diseases such as peroxisomal disorders, but little is known on the intracellular activation of Mitogen-activated protein kinases (MAPKs). Strictly related to oxidative stress, a correct autophagic machinery is essential to eliminated oxidized proteins and damaged organelles. The aims of the current study are to investigate a possible implication of MAPK pathways and autophagy impairment as markers and putative therapeutic targets in X-ALD and ZSDs.
METHODS
Three patients with ZSD (2 M, 1 F; age range 8-17 years) and five patients with X-ALD (5 M; age range 5- 22 years) were enrolled. A control group included 6 healthy volunteers. To evaluate MAPKs pathway, p-p38 and p-JNK were assessed by western blot analysis on peripheral blood mononuclear cells. LC3II/LC3I ratio was evaluated ad marker of autophagy.
RESULTS
X-ALD and ZSD patients showed elevated p-p38 values on average 2- fold (range 1.21- 2.84) and 3.30-fold (range 1.56- 4.26) higher when compared with controls, respectively. p-JNK expression was on average 12-fold (range 2.20-19.92) and 2.90-fold (range 1.43-4.24) higher in ZSD and X-ALD patients than in controls. All patients had altered autophagic flux as concluded from the reduced LC3II/I ratio.
CONCLUSIONS
In our study X-ALD and ZSD patients present an overactivation of MAPK pathways and an inhibition of autophagy. Considering the absence of successful therapies and the growing interest towards new therapies with antioxidants and autophagy inducers, the identification and validation of biomarkers to monitor optimal dosing and biological efficacy of the treatments is of prime interest.
Topics: Humans; Child; Adolescent; Child, Preschool; Young Adult; Adult; Adrenoleukodystrophy; Zellweger Syndrome; Leukocytes, Mononuclear; Peroxisomes; Oxidation-Reduction
PubMed: 37974207
DOI: 10.1186/s13023-023-02940-x -
Stem Cell Research Dec 2023X-linked adrenoleukodystrophy (ALD) is a rare peroxisome disease with phenotypic heterogeneity. There is a lack of suitable in vitro models to study its pathogenesis. We...
X-linked adrenoleukodystrophy (ALD) is a rare peroxisome disease with phenotypic heterogeneity. There is a lack of suitable in vitro models to study its pathogenesis. We established two strains of iPSCs from skin fibroblasts of patients with childhood cerebral ALD and Addison's disease, respectively. CytoTune™2.0 Sendai reprogramming kit was used. The iPSC lines showed typical stem cell morphology, normal karyotype, and carrying ABCD1 variation. The iPSC lines express pluripotency markers, and have the capacity to differentiate into three germ layers. iPSCs can be used as an alternative cell source for ALD in vitro model to study its pathogenesis and therapeutic strategies.
Topics: Humans; Child; Induced Pluripotent Stem Cells; Adrenoleukodystrophy; Cell Differentiation; Fibroblasts
PubMed: 37948838
DOI: 10.1016/j.scr.2023.103243 -
Frontiers in Neurology 2023RNA polymerase III-related leukodystrophy (POLR3-related leukodystrophy) is a rare, genetically determined hypomyelinating disease arising from biallelic pathogenic...
RNA polymerase III-related leukodystrophy (POLR3-related leukodystrophy) is a rare, genetically determined hypomyelinating disease arising from biallelic pathogenic variants in genes encoding subunits of RNA polymerase III (Pol III). Here, we describe the first reported case of POLR3-related leukodystrophy caused by biallelic pathogenic variants in , encoding the RPC4 subunit of Pol III. The individual, a female, demonstrated delays in walking and expressive and receptive language as a child and later cognitively plateaued. Additional neurological features included cerebellar signs (e.g., dysarthria, ataxia, and intention tremor) and dysphagia, while non-neurological features included hypodontia, hypogonadotropic hypogonadism, and dysmorphic facial features. Her MRI was notable for diffuse hypomyelination with myelin preservation of early myelinating structures, characteristic of POLR3-related leukodystrophy. Exome sequencing revealed the biallelic variants in , a missense variant (c.541C > T, p.P181S) and an intronic splice site variant (c.656-6G > A, p.?). Functional studies of the patient's fibroblasts demonstrated significantly decreased RNA-level expression of , along with reduced expression of other Pol III subunit genes. Notably, Pol III transcription was also shown to be aberrant, with a significant decrease in RNA and several distinct tRNA genes analyzed. Affinity purification coupled to mass spectrometry of the p.P181S variant showed normal assembly of Pol III subunits yet altered interaction of Pol III with the PAQosome chaperone complex, indicating the missense variant is likely to alter complex maturation. This work identifies biallelic pathogenic variants in as a novel genetic cause of POLR3-related leukodystrophy, expanding the molecular spectrum associated with this disease, and proposes altered tRNA homeostasis as a factor in the underlying biology of this hypomyelinating disorder.
PubMed: 37915380
DOI: 10.3389/fneur.2023.1254140 -
Free Neuropathology Jan 2023The history of adrenoleukodystrophy (ALD), adrenomyeloneuropathy (AMN) and other peroxisomal diseases is exemplary for the stunning progress of scientific medicine... (Review)
Review
The history of adrenoleukodystrophy (ALD), adrenomyeloneuropathy (AMN) and other peroxisomal diseases is exemplary for the stunning progress of scientific medicine within the past 50 years. Like many breakthroughs in medicine, the detailed analysis of patients' pathologically affected tissues was instrumental, resulting in stepwise systematic clarification of what had remained enigmatic until the 1970s. This flashback paper is a recollection of the first neuropathological description of a slowly evolving clinical phenotype, spastic paraparesis with adrenal insufficiency, in a young adult by Budka et al. 1976 [3], using virtual microscopy of the original histologic slides. The clinico-pathological presentation derives from the classical cerebral ALD phenotype in boys, where electron microscopy demonstrated the underlying pathological hallmark of characteristic lipid inclusions shared by both phenotypes. Our report allowed the delineation of a new disease type almost simultaneously described in more cases as AMN by Griffin et al. 1977 [4] and Schaumburg et al. 1977 [11]. Moreover, our report indicated clinical heterogeneity in the ALD disease group that, as shown later, extends further to females, to Addison-only, and even to asymptomatic subjects. The gene underlying ALD was discovered in 1993 as a defect in the gene. Yet, it has hitherto remained unclear how the gene defect causes the strikingly broad and unpredictable phenotypic spectrum of ALD/AMN.
PubMed: 37915358
DOI: 10.17879/freeneuropathology-2023-5115 -
Endocrine Feb 2024X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal disorder caused by the variations in the ATP-binding cassette sub-family D member 1 (ABCD1) gene. This study is...
X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal disorder caused by the variations in the ATP-binding cassette sub-family D member 1 (ABCD1) gene. This study is the first to report central precocious puberty (CPP) in individuals with X-ALD. A 6-year-old boy exhibited mucocutaneous pigmentation, increased plasma adrenocorticotropic hormone levels, and elevated very long-chain fatty acids (VLCFA). We identified a variant, c.1826A>G (p. Glu609Gly), in exon 8 of the ABCD1 gene in the proband. Additionally, he displayed rapid growth, testicular volume of 5-6 mL, the onset of pubic hair, and pubertal levels of luteinizing hormone (LH), all meeting the diagnostic criteria for CPP.
Topics: Male; Humans; Child; Adrenoleukodystrophy; ATP-Binding Cassette Transporters; Puberty, Precocious; Family; Exons; Fatty Acids
PubMed: 37845577
DOI: 10.1007/s12020-023-03562-w -
European Radiology Experimental Oct 2023In adrenoleukodystrophy (ALD), contrast enhancement (CE) is a disease activity marker, but there is uncertainty about the optimal delay, if any, between contrast...
In adrenoleukodystrophy (ALD), contrast enhancement (CE) is a disease activity marker, but there is uncertainty about the optimal delay, if any, between contrast injection and magnetic resonance imaging (MRI) acquisition to avoid false-negative results. We acquired axial two-dimensional (2D) and three-dimensional (3D) T1-weighted gradient-echo every 6 min from 0 to 36 min after contrast administration (gadobutrol 0.1 mmol/kg) in an ALD patient with enlarging white matter lesions and progressive neuropsychological symptoms, using a 3-T magnet. The image signal over time was qualitatively assessed and measured in two regions of interest. On 3D sequences, no definite CE was appreciated, whereas on 2D sequences, CE was noticed after 6 min and definitely evident after 12 min, when 73% of the maximum signal intensity was measured. In ALD subjects, contrast-enhanced 2D T1-weighted gradient-echo sequences acquired at least 10 min after contrast injection may be considered to reduce false negative results.Relevance statementOur report is the first attempt to find an optimal delay between contrast administration and T1-weighted acquisition in cALD patients in order to correctly detect disease activity and avoid false negative results.Key points• The optimal time between contrast injection and image acquisition for MRI of adrenoleukodystrophy is unknown.• Contrast enhancement predicts adrenoleukodystrophy progression and could help patient's selection for the therapy.• We acquired two post-contrast T1-GRE-2D/3D sequences several times to find the best injection-time.• T1-weighted 2D GRE resulted more sensitive than T1-weighted 3D GRE even after long intervals from injection.• A delay of about 10 min may minimize false negatives.
Topics: Humans; Contrast Media; Adrenoleukodystrophy; Magnetic Resonance Imaging
PubMed: 37782421
DOI: 10.1186/s41747-023-00373-6 -
Biomolecules Aug 2023X-linked adrenoleukodystrophy (X-ALD), the most common peroxisomal disorder, is caused by mutations in the peroxisomal transporter ABCD1, resulting in the accumulation...
X-linked adrenoleukodystrophy (X-ALD), the most common peroxisomal disorder, is caused by mutations in the peroxisomal transporter ABCD1, resulting in the accumulation of very long-chain fatty acids (VLCFA). Strongly affected cell types, such as oligodendrocytes, adrenocortical cells and macrophages, exhibit high cholesterol turnover. Here, we investigated how ABCD1 deficiency affects cholesterol metabolism in human X-ALD patient-derived fibroblasts and CNS tissues of Abcd1-deficient mice. Lipidome analyses revealed increased levels of cholesterol esters (CE), containing both saturated VLCFA and mono/polyunsaturated (V)LCFA. The elevated CE(26:0) and CE(26:1) levels remained unchanged in LXR agonist-treated Abcd1 KO mice despite reduced total C26:0. Under high-cholesterol loading, gene expression of SOAT1, converting cholesterol to CE and lipid droplet formation were increased in human X-ALD fibroblasts versus healthy control fibroblasts. However, the expression of NCEH1, catalysing CE hydrolysis and the cholesterol transporter ABCA1 and cholesterol efflux were also upregulated. Elevated Soat1 and Abca1 expression and lipid droplet content were confirmed in the spinal cord of X-ALD mice, where expression of the CNS cholesterol transporter Apoe was also elevated. The extent of peroxisome-lipid droplet co-localisation appeared low and was not impaired by ABCD1-deficiency in cholesterol-loaded primary fibroblasts. Finally, addressing steroidogenesis, progesterone-induced cortisol release was amplified in X-ALD fibroblasts. These results link VLCFA to cholesterol homeostasis and justify further consideration of therapeutic approaches towards reducing VLCFA and cholesterol levels in X-ALD.
Topics: Humans; Mice; Animals; Adrenoleukodystrophy; ATP Binding Cassette Transporter, Subfamily D, Member 1; ATP-Binding Cassette Transporters; Fatty Acids; Homeostasis; Cholesterol
PubMed: 37759733
DOI: 10.3390/biom13091333 -
International Journal of Neonatal... Sep 2023Newborn screening (NBS) for X-linked adrenoleukodystrophy (ALD) can identify affected individuals before the onset of life-threatening manifestations. Some countries...
Newborn screening (NBS) for X-linked adrenoleukodystrophy (ALD) can identify affected individuals before the onset of life-threatening manifestations. Some countries have decided to only screen boys (sex-specific screening). This study investigates the attitudes of individuals with ALD towards sex-specific NBS for ALD. A questionnaire was sent to all patients in the Dutch ALD cohort. Invitees were asked who they thought should be screened for ALD: only boys, both boys and girls or neither. The motives and background characteristics of respondents were compared between screening preferences. Out of 108 invitees, 66 participants (61%), 38 men and 28 women, participated in this study. The majority (n = 53, 80%) favored screening both newborn boys and girls for ALD, while 20% preferred boys only. None of the respondents felt that newborns should not be screened for ALD. There were no differences in the background characteristics of the respondents between screening preferences. Our study revealed a diverse range of motivations underlying respondents' screening preferences. This study is one of the first to investigate the attitudes of patients towards sex-specific screening for ALD. The outcomes of this study can offer insights to stakeholders engaged in the implementation of NBS programs. ALD patients are important stakeholders who can provide valuable input in this process.
PubMed: 37754777
DOI: 10.3390/ijns9030051 -
Pediatric Neurology Nov 2023Biallelic pathogenic variants in SLC17A5 cause three forms of free sialic acid storage disease categorized based on severity from least to most severe: Salla disease,...
BACKGROUND
Biallelic pathogenic variants in SLC17A5 cause three forms of free sialic acid storage disease categorized based on severity from least to most severe: Salla disease, intermediate-severe Salla disease, and infantile free sialic acid storage disease. Intermediate-severe Salla disease is the most recently described form. Here, we report a longitudinal characterization of intermediate-severe Salla disease progression in two sisters carrying the following biallelic variants in SLC17A5: c.406A>G (p.Lys136Glu) and c.819+1G>A.
METHODS
A retrospective review of medical records was performed. A developmental questionnaire was completed to obtain further clinical information. For functional characterization of the predicted splice site variant, RNA was extracted from patient blood samples and sequenced.
RESULTS
Disease onset occurred within the first six months of life in both patients. Early childhood development was delayed with achievement of some milestones followed by a developmental plateau in late childhood. After this, both patients began a slow and progressive neurological regression in adolescence. Functional studies confirmed the pathogenicity of the c.819+1G>A variant, resulting in a frameshift and deletion of exon 6.
CONCLUSIONS
We present a detailed study describing the clinical course of intermediate-severe Salla disease with over 15 to 20 years of evolution and demonstrate the pathogenicity of the c.819+1G>A splice site variant.
Topics: Adolescent; Humans; Child; Child, Preschool; Sialic Acid Storage Disease; Mutation; N-Acetylneuraminic Acid; Disease Progression
PubMed: 37713976
DOI: 10.1016/j.pediatrneurol.2023.08.013