Therapy of X-linked adrenoleukodystrophy

Pre-meiotic deletion of PEX5 causes spermatogenesis failure and infertility in mice

Peroxisomes are involved in the regulation of various pathological processes. Peroxisomal biogenesis factor 5 (PEX5), which plays an essential role in peroxisomal biogenesis, is critical for reactive oxygen species (ROS) accumulation. However, its underlying functions in spermatogenesis have not yet been identified. Pex5 was deleted by crossing Stra8-Cre mice with Pex5^flox/flox mice before the onset of meiosis. The morphology of testes and epididymides, spermatogenesis function, and fertility in both wild type (WT) and Pex5^-/- mice were analysed by haematoxylin and eosin (HE) and immunofluorescent staining. Mechanism of PEX5 affecting peroxisomes and spermatogenesis were validated by Western blot and transmission electron microscopy (TEM). Transcriptome RNA sequencing (RNA-seq) was used to profile the dysregulated genes in testes from WT and Pex5^-/- mice on postnatal day (P) 35. The adult Pex5 knockout male mice were completely sterile with no mature sperm production. Loss of Pex5 in spermatocytes resulted in multinucleated giant cell formation, meiotic arrest, abnormal tubulin expression, and deformed acrosome formation. Furthermore, Pex5 deletion led to delayed DNA double-strand break repair and improper crossover at the pachytene stage. Impaired peroxisome function in Pex5 knockout mice induced ROS redundancy, which in turn led to an increase in germ cell apoptosis and a decline in autophagy. Pex5 regulates ROS during meiosis and is essential for spermatogenesis and male fertility in mice.

Successful Pregnancy Following Preimplantation Genetic Diagnosis of Adrenoleukodystrophy by Detection of Mutation on the ABCD1 Gene

Background

Adrenoleukodystrophy (ALD) is a rare sex-linked recessive disorder that disrupts adrenal gland function and the white matter of the nervous system. According to recent epidemiological statistics, up to this moment, the disease is the most recorded peroxisomal disorder. ABCD1 is a gene related to ALD, with more than 850 unique mutations have been reported. Early diagnosis of the disease would help to consult families with ALD to plan for interventions to prevent passing along the pathogenic mutations to their children.

Material and Methods

A heterozygous ABCD1 gene mutation related to ALD found in a Vietnamese woman was used to design primers for the polymerase chain reaction (PCR) to amplify the segment spanning the mutation. Then, combining sequencing methods for the PCR products, especially Sanger sequencing and next-generation sequencing (NGS), a protocol was developed to detect mutations on the ABCD1 gene to apply for the DNA samples of in-vitro fertilization (IVF) embryos biopsied at the blastocyst stage to screen for pathogenic alleles.

Results

The established protocol for PGD of ALD detected mutant alleles in 5/8 embryos (62.5%), while the remaining 3 embryos (37.5%) did not carry any mutation. One of the 3 embryos was transferred, and a healthy female baby was born after a full-term pregnancy.

Conclusion

The developed protocol was helpful for the preimplantation genetic diagnosis process to help families with the monogenic disease of ALD but wish to have healthy children.

Allogeneic hematopoietic stem cell transplantation with myeloablative conditioning for adult cerebral X-linked adrenoleukodystrophy

The adult cerebral form of X-linked adrenoleukodystrophy (ACALD), an acute inflammatory demyelinating disease, results in a rapidly progressive neurodegeneration, typically leading to severe disability or death within a few years after onset. We have treated 15 men who had developed ACALD with allogeneic hematopoietic stem cell transplantation (HSCT) from matched donors after myeloablative conditioning with busulfan and cyclophosphamide. All patients engrafted and 11 survived (estimated survival 73 ± 11%), 8 with stable cognition and 7 of them with stable motor function (estimated event-free survival 36 ± 17%). Death after transplantation occurred within the first year after HSCT and was caused either primarily by infection (N = 3) or due to disease progression triggered by infection (N = 1). Patients with minor myelopathic symptoms (N = 4) or with no or mild cerebral symptoms pre-transplant (N = 7) had an excellent outcome. In contrast, no patient with major neurological symptoms associated with an extensive involvement of pyramidal tract fibres in the internal capsule (N = 5) survived without cognitive deterioration. Notably, early leukocyte recovery was associated with dismal outcome for yet unknown reasons. All 10 tested survivors showed a reduction of plasma hexacosanoic acid (C26:0) in the absence of Lorenzo's oil. Over time, the event-free survival could be improved from 2 out of 8 patients (25%) before 2013 to 5 out of 7 patients (71%) thereafter. Therefore, allogeneic HSCT appears to be a suitable treatment option for carefully selected ACALD patients when transplanted from matched donors after myeloablative, busulfan-based conditioning.

[Overview of X-linked adrenoleukodystrophy in Morocco: results of the implementation of the program of clinical and biological diagnosis]

Introduction

L'adrénoleucodystrophie liée à l'X (X-ALD) est une maladie neurodégénérative sévère, due à des mutations du gène ABCD1. Elle se manifeste par une atteinte du système nerveux central et périphérique, une insuffisance surrénalienne et une atteinte des testicules chez le garçon. Son diagnostic repose sur le dosage des Acides Gras à Très Longue Chaine. Le diagnostic précoce est d'une grande importance puisque il définit l'accessibilité aux traitements selon le stage de la maladie.

Méthodes

Nous avons mis en place un programme de diagnostic de l'X-ALD au Maroc au niveau de l'Hôpital d'enfants et du Laboratoire centrale des maladies héréditaires et du métabolisme de Rabat. Le programme s'articule sur trois axes à savoir : le recrutement des patients, le diagnostic et la sensibilisation. Le diagnostic s'effectue selon trois protocoles : un protocole pour les cas symptomatiques, un deuxième pour les cas asymptomatiques et un troisième pour les femmes hétérozygotes.

Résultats

Durant trois ans après la mise en place de notre programme de diagnostic de l'Adrénoleucodystrophie liée à l'X, nous avons diagnostiqué la maladie chez sept familles, avec neuf garçons et trois femmes hétérozygotes. Tous les enfants diagnostiqués présentaient la forme cérébrale démyélinisante. Toutes les femmes hétérozygotes étaient asymptomatiques. Une prise en charge thérapeutique a été mise place selon la symptomatologie de chaque cas.

Conclusion

l'X-ALD est une maladie rare. Notre programme de diagnostique a permis de diagnostiquer un nombre important de cas, ce qui montre son importance. Les compagnes de sensibilisation auprès des professionnels permettront de mieux comprendre la maladie et mieux la diagnostiquer et ainsi donner accès à un nombre plus élevé de patients.

Management of X-linked adrenoleukodystrophy in Morocco: actual situation

OBJECTIVES

X-linked adrenoleukodystrophy is a neurodegenerative disorder caused by mutations in the ABCD1 gene. Adrenomyeloneuropathy and childhood cerebral Adrenoleukodystrophy are the most common phenotypes. This paper focuses on a descriptive study of the first program of diagnosis, treatment, and follow-up of this disease in Morocco.

RESULTS

We developed three protocols of X-linked Adrenoleukodystrophy management: general protocol, asymptomatic protocol, and heterozygous protocol. Over a period of 5 years, we recruited eight families with 16 patients. Clinically, the presentation is primary adrenal insufficiency and behavioral changes. All patients had elevated levels of very long fatty acids. This is the first study of X-linked adrenoleukodystrophy in Morocco. It shows the importance of this metabolic disease and broadens perspectives in terms of its diagnosis and its treatment.

Childhood leukodystrophies: A literature review of updates on new definitions, classification, diagnostic approach and management

Childhood leukodystrophies are a growing category of neurological disorders in pediatric neurology practice. With the help of new advanced genetic studies such as whole exome sequencing (WES) and whole genome sequencing (WGS), the list of childhood heritable white matter disorders has been increased to more than one hundred disorders. During the last three decades, the basic concepts and definitions, classification, diagnostic approach and medical management of these disorders much have changed. Pattern recognition based on brain magnetic resonance imaging (MRI), has played an important role in this process. We reviewed the last Global Leukodystrophy Initiative (GLIA) expert opinions in definition, new classification, diagnostic approach and medical management including emerging treatments for pediatric leukodystrophies.

Emerging treatments for pediatric leukodystrophies

The leukodystrophies are a heterogeneous group of inherited disorders with broad clinical manifestations and variable pathologic mechanisms. Improved diagnostic methods have allowed identification of the underlying cause of these diseases, facilitating identification of their pathologic mechanisms. Clinicians are now able to prioritize treatment strategies and advance research in therapies for specific disorders. Although only a few of these disorders have well-established treatments or therapies, a number are on the verge of clinical trials. As investigators are able to shift care from symptomatic management of disorders to targeted therapeutics, the unmet therapeutic needs could be reduced for these patients.

X-linked adrenoleukodystrophy presenting as attention deficit hyperactivity disorder

X-linked adrenoleukodystrophy (X-ALD) is one the leukodystrophies causing a progressive decline in neurological function mainly affecting the children. The most common symptoms are changes in behavior, including social withdrawal or aggression, poor memory or poor scholastic performance. Here, we present a 7-year-old boy who presented with symptoms of inattention and hyperactivity and later turned out to be a case of X-ALD.

Disease specific therapies in leukodystrophies and leukoencephalopathies

Leukodystrophies are a heterogeneous, often progressive group of disorders manifesting a wide range of symptoms and complications. Most of these disorders have historically had no etiologic or disease specific therapeutic approaches. Recently, a greater understanding of the pathologic mechanisms associated with leukodystrophies has allowed clinicians and researchers to prioritize treatment strategies and advance research in therapies for specific disorders, some of which are on the verge of pilot or Phase I/II clinical trials. This shifts the care of leukodystrophy patients from the management of the complex array of symptoms and sequelae alone to targeted therapeutics. The unmet needs of leukodystrophy patients still remain an overwhelming burden. While the overwhelming consensus is that these disorders collectively are symptomatically treatable, leukodystrophy patients are in need of advanced therapies and if possible, a cure.

Ophthalmic manifestations of inherited neurodegenerative disorders

Ophthalmic findings are common features of neurodegenerative disorders and, in addition to being clinically important, have emerged as potentially useful biomarkers of disease progression in several conditions. Clinically, these visual system abnormalities can be a clue to diagnosis, as well as being a prominent cause of disability in affected patients. In this Review, we describe the various afferent visual system and other ophthalmic features of inherited neurodegenerative disorders, including the muscular dystrophies, Friedreich ataxia, the spinocerebellar ataxias, hereditary spastic paraplegia, Charcot-Marie-Tooth disease, and other conditions. We focus on the expanding role of optical coherence tomography in diagnostic imaging of the retina and optic nerve head, and the possible use of ophthalmic findings as biomarkers of disease severity in hereditary neurodegenerative disorders. In addition, we discuss the ophthalmic manifestations and treatment implications of mitochondrial dysfunction, which is a feature of many inherited neurodegenerative diseases.

X-linked adrenoleukodystrophy: are signs of hypogonadism always due to testicular failure?

We present the clinical and hormonal findings of a young male with X-linked adrenoleukodystrophy (X-ALD), with special emphasis on the biochemical and clinical pattern of hypogonadism. A patient, with primary adrenal insufficiency since the age of 5 years, developed progressive neurological symptoms at the age of 29. Diagnosis of X-ALD was established by elevated serum very long chain fatty acids (VLCFAs) and genetic testing. His sexual body hair was sparse. Hormonal investigations revealed normal testosterone and inappropriately elevated LH levels. Androgen receptor gene analysis was negative for mutations or polymorphic variants associated with decreased receptor activity. Signs of hypogonadism in patients with confirmed X-ALD are not exclusively due to primary testicular failure. Tissue specific androgen resistance represents an alternative possibility. Since no loss-of-function mutations were detected in the androgen receptor, it is speculated that the patient's androgen resistance could be part of a functional defect mediated through VLCFA accumulation at the testosterone receptor and/or post-receptor levels.

Myelin peroxisomes - essential organelles for the maintenance of white matter in the nervous system

Peroxisomes are cellular compartments primarily associated with lipid metabolism. Most cell types, including nervous system cells, harbor several hundred of these organelles. The importance of peroxisomes for central nervous system white matter is evidenced by a variety of human peroxisomal disorders with neurological impairment frequently involving the white matter. Moreover, the most frequent childhood white matter disease, X-linked adrenoleukodystrophy, is a peroxisomal disorder. During the past decade advances in imaging techniques have enabled the identification of peroxisomes within the myelin sheath, especially close to nodes of Ranvier. Although the function of myelin peroxisomes is not solved yet on molecular level, recently acquired knowledge suggests a central role for these organelles in axo-glial metabolism. This review focuses on the biology of myelin peroxisomes as well as on the pathology of myelin and myelinated axons that is observed as a consequence of partial or complete peroxisomal dysfunction in the brain.

Clinical manifest x-linked recessive adrenoleukodystrophy in a female

Adrenoleukodystrophy (ALD) is a rare X-linked inherited leukodystrophy with a reduced capacity for degradation of very long chain fatty acids (VLCFAs). The intracellular accumulation of VLCFA leads to demyelination in the central nervous system (CNS) and cell destruction in the adrenal glands. ALD primarily affects males; however, females may develop milder symptoms that may be difficult to recognize. The present report describes a 35-year-old female who experienced a feeling of heaviness in the upper and lower limbs, pain in both knees, and difficulty climbing stairs, running, and jumping. Clinical examination revealed decreased sensitivity in the feet, particularly to touch. Deep tendon reflexes in the lower limbs were brisk, and Babinski's sign was present bilaterally. Multiple sclerosis (MS) was excluded, and all clinical and biochemical tests were normal. After two years of progressing symptoms, the patient was reevaluated and plasma levels of VLCFA were found to be elevated. Seven years prior to this finding, the patient had been found to be heterozygous for the missense mutation c.1679C> T, p.Pro560Leu on the ABCD1 gene (ATP-Binding Cassette subfamily D1). In conclusion, the patient's symptoms could be attributed to ALD. The present case underlines the importance of reevaluating family history in women presenting with vague neurological symptoms.

Viral vectors and delivery strategies for CNS gene therapy

This review aims to provide a broad overview of the targets, challenges and potential for gene therapy in the CNS, citing specific examples. There are a broad range of therapeutic targets, with very different requirements for a suitable viral vector. By utilizing different vector tropisms, novel routes of administration and engineered promoter control, transgenes can be targeted to specific therapeutic applications. Viral vectors have proven efficacious in preclinical models for several disease applications, spurring several clinical trials. While the field has pushed the limits of existing adeno-associated virus-based vectors, a next generation of vectors based on rational engineering of viral capsids should expand the application of gene therapy to be more effective in specific therapeutic applications.

Strength: a relevant link to functional performance in the neurodegenerative disease of adrenomyeloneuropathy

BACKGROUND

With progressive abnormalities in leg strength, tone, and sensation, adrenomyeloneuropathy (AMN) is a differential diagnosis for multiple sclerosis and hereditary spastic paraparesis. AMN pathology has been linked to weakness, making it a relevant model to evaluate the relationship between neurodegeneration and disability. Quantifying symptom severity in AMN is essential for treatment development in rehabilitative management.

OBJECTIVE

To identify deficits in body functions, activity, and participation of people with AMN and provide a practical framework for evaluating the severity of disability.

METHODS

Cohort analysis of 142 participants with AMN.

MEASURES

of body functions (leg strength, vibration sensation, range of motion, and spasticity), activity (walk velocity, standing balance, Timed Up and Go, and Sit-to-Stand Time), and participation (6-Minute Walk) are evaluated. Regression analyses identify relationships between the measures. A staging framework (mild, moderate, and severe) reflects the continuum of disability. Finally, an analysis of variance/Kruskal-Wallis was used for between-stage and sex differences among the variables.

RESULTS

Strength is the strongest correlate for the 5 measures of activity and participation. Staging based on weakness distinguishes 3 levels of severity along a continuum of disability. Differences between the sexes are more prevalent earlier in the continuum but show equally severe deficits in the last stage.

CONCLUSIONS

In AMN, staging based on degrees of weakness provides a practical means to characterize the severity of common deficits in body functions as well as activity and participation at each stage, to direct the evaluation. Such information could help clinicians develop more effective rehabilitative techniques.

Adrenoleukodystrophy in female heterozygotes: underrecognized and undertreated

X-linked adrenoleukodystrophy (X-ALD) is a neurodegenerative disease resulting from mutations in the gene ABCD1 and alterations in peroxisomal beta-oxidation of long chain fatty acids. As it has been frequently discussed, it manifests a wide range of phenotypes in male, with progressive myelopathy being the most common. Even though the gene is localized to the X-chromosome and a region subject to X-inactivation, female carriers still are affected significantly by this condition. It has been stated that between 20 and 50% of women who are carriers may manifest some symptoms and recent evidence has suggested the differences in disease manifestations and relative rates of progression between men and women. However there have been only limited studies specifically addressing this and to date there has been no comprehensive review discussing the different phenotypes in female carriers, as well as the differences in disease onset, progression, disability, nervous system pathology and neuroimaging patterns compared to affected males. This is of key importance as similarities and differences between genders will assist in determining how best to target therapies in all affected individuals as opportunities for treatment present themselves. As will be further addressed in this review, we need to improve our understanding of the associations of emergent neuroimaging techniques to physical disability in this population. We reviewed the clinical presentations in the carrier population, the distinct disability profile and neuroimaging findings in order to put together pieces of this neglected segment in X-ALD and give direction to further studies.

Preferential expression of mutant ABCD1 allele is common in adrenoleukodystrophy female carriers but unrelated to clinical symptoms

Background

Approximately 20% of adrenoleukodystrophy (X-ALD) female carriers may develop clinical manifestations, typically consisting of progressive spastic gait, sensory deficits and bladder dysfunctions. A skewing in X Chromosome Inactivation (XCI), leading to the preferential expression of the X chromosome carrying the mutant ABCD1 allele, has been proposed as a mechanism influencing X-linked adrenoleukodystrophy (X-ALD) carrier phenotype, but reported data so far are conflicting.

Methods

To shed light into this topic we assessed the XCI pattern in peripheral blood mononuclear cells (PBMCs) of 30 X-ALD carriers. Since a frequent problem with XCI studies is the underestimation of skewing due to an incomplete sample digestion by restriction enzymes, leading to variable results, we developed a pyrosequencing assay to identify samples completely digested, on which to perform the XCI assay. Pyrosequencing was also used to quantify ABCD1 allele-specific expression. Moreover, very long-chain fatty acid (VLCFA) levels were determined in the same patients.

Results

We found severely (≥90:10) or moderately (≥75:25) skewed XCI in 23 out of 30 (77%) X-ALD carriers and proved that preferential XCI is mainly associated with the preferential expression of the mutant ABCD1 allele, irrespective of the manifestation of symptoms. The expression of mutant ABCD1 allele also correlates with plasma VLCFA concentrations.

Conclusions

Our results indicate that preferential XCI leads to the favored expression of the mutant ABCD1 allele. This emerges as a general phenomenon in X-ALD carriers not related to the presence of symptoms. Our data support the postulated growth advantage of cells with the preferential expression of the mutant ABCD1 allele, but argue against the use of XCI pattern, ABCD1 allele-specific expression pattern and VLCFA plasma concentration as biomarkers to predict the development of symptoms in X-ALD carriers.

Leukodystrophies

Leukodystrophies comprise a broad group of progressive, inherited disorders affecting mainly myelin. They often present after a variable period of normalcy with a variety of neurologic problems. Though the ultimate diagnosis is not found in many patients with leukodystrophies, distinctive features unique to them aid in diagnosis, treatment and prognostication. The clinical characteristics, etiologies, diagnostic testing and treatment options are reviewed in detail for some of the major leukodystrophies: X-linked adrenoleukodystrophy, Krabbe disease, metachromatic leukodystrophy, Pelizaeus-Merzbacher disease, Alexander disease, Canavan disease, megalencephalic leukoencephalopathy with subcortical cysts and vanishing white matter disease.

Myelin lesions associated with lysosomal and peroxisomal disorders

Abnormalities of myelin are common in lysosomal and peroxisomal disorders. Most display a primary loss of myelin in which the myelin sheath and/or oligodendrocytes are selectively targeted by diverse pathogenetic processes. The most severe and, hence, clinically relevant are heritable diseases predominantly of infants and children, the leukodystrophies: metachromatic, globoid cell (Krabbe disease) and adreno-leukodystrophy. Our still limited understanding of these diseases has derived from multiple sources: originally, neurological-neuropathologic-neurochemical correlative studies of the natural disease in humans or other mammals, which has been enhanced by more sophisticated and contemporary techniques of cell and molecular biology. Transgenic mouse models seem to be the most promising methodology, allowing the examination of the cellular role of lysosomes and peroxisomes for formation and maintenance of both myelin and axons, and providing initial platforms to evaluate therapies. Treatment options are woefully inadequate and in their nascent stages, but still inspire some hope for the future.

General aspects and neuropathology of X-linked adrenoleukodystrophy

X-adrenoleukodystrophy (X-ALD) is a metabolic, peroxisomal disease affecting the nervous system, adrenal cortex and testis resulting from inactivating mutations in ABCD1 gene which encodes a peroxisomal membrane half-adenosine triphosphate (ATP)-binding cassette transporter, ABCD1 (or ALDP), whose defect is associated with impaired peroxisomal beta-oxidation and accumulation of saturated very long-chain fatty acids (VLCFA) in tissues and body fluids. Several phenotypes are recognized in male patients including cerebral ALD in childhood, adolescence or adulthood, adrenomyeloneuropathy (AMN), Addison's disease and, eventually, gonadal insufficiency. Female carriers might present with mild to severe myeloneuropathy that resembles AMN. There is a lack of phenotype-genotype correlations, as the same ABCD1 gene mutation may be associated with different phenotypes in the same family, suggesting that genetic, epigenetic, environmental and stochastic factors are probably contributory to the development and course of the disease. Degenerative changes, like those seen in pure AMN without cerebral demyelination, are characterized by loss of axons and secondary myelin in the long tracts of the spinal cord, possibly related to the impaired lipid metabolism of VLCFAs and the associated alterations (ie, oxidative damage). Similar lesions are encountered following inactivation of ABCD1 in mice (ABCD1(-)). A different and more aggressive phenotype is secondary to cerebral demyelination, very often accompanied by inflammatory changes in the white matter of the brain and associated with activation of T lymphocytes, CD1 presentation and increased levels of cytokines, gamma-interferon, interleukin (IL)-1alpha, IL-2 and IL-6, Granulocyte macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-alpha, chemokines and chemokine receptors.

Leukodystrophies with late disease onset: an update

PURPOSE OF REVIEW

Knowledge of the metabolic and genetic basis of known and previously unknown leukodystrophies is constantly increasing, opening new treatment options such as enzyme replacement or cell-based therapies. This brief review highlights some recent work, particularly emphasizing results from studies in adulthood leukodystrophies.

RECENT FINDINGS

Evidence from recent studies suggests increasing importance of metabolic dysfunctions, for example, in peroxisomal lipid metabolism or energy homeostasis, influencing axonal integrity and oligodendrocyte function and leading to white matter demyelination. In addition, diagnostic and therapeutic progress in metachromatic leukodystrophy, X-linked adrenoleukodystrophy, Krabbe diseases and other rare leukodystrophies with late onset are summarized.

SUMMARY

Better understanding of leukodystrophies in neurological routine practice is of crucial importance for differentiating between other white matter diseases such as toxic, inflammatory or vascular leukoencephalopathies. Many leukodystrophies are particularly important to recognize because specific treatments already exist or are currently under investigation. The article also provides an overview of currently known leukodystrophies in adulthood.

Very long-chain fatty acid accumulation causes lipotoxic response via 5-lipoxygenase in cerebral adrenoleukodystrophy

Childhood adrenoleukodystrophy (cALD) is a metabolic disorder in which very long-chain fatty acids (VLCFA) accumulate due to ALD protein gene defects, ultimately leading to lipotoxicity-induced neuroinflammatory demyelinating disease. Therefore, we examined VLCFA-mediated alterations in the metabolism of lipoxidative enzymes and inflammatory mediators in the cALD brain. 5-Lipoxygenase (5-LOX)-derived leukotrienes were significantly elevated in all the areas of white matter in the cALD brain. Unlike cyclooxygenase-2 expression, which was moderately high only in the plaque area, expression of 5-LOX and cytosolic phospholipase A2 was prominent in all the areas. This lipoxidative burden in the cALD brain was further shown by reduced levels of glutathione and enhanced expression of heat shock protein-70/manganese superoxide dismutase. These pathological observations were confirmed through in vitro mechanistic investigation. After increasing VLCFA through silencing Abcd1+Abcd2 in mouse primary astrocytes, enhanced expression of 5-LOX was observed, and this increased expression was blocked by treatment with monoenoic fatty acids. These results link the previously observed accumulation of VLCFA in cALD to the 5-LOX enzyme pathway. A similar increase in 5-LOX expression in astrocytes was also detected following treatment with exogenous VLCFA (C26:0). In sum, through 5-LOX activation, VLCFA accumulation causes a lipotoxic response consistent with cALD brain pathology.

A three-year-old boy with X-linked adrenoleukodystrophy and congenital pulmonary adenomatoid malformation: a case report

INTRODUCTION

X-linked adrenoleukodystrophy leads to demyelination of the nervous system, adrenal insufficiency, and accumulation of long-chain fatty acids. Most young patients with X-linked adrenoleukodystrophy develop seizures and progressive neurologic deficits, and die within the first two decades of life. Congenital or acquired disorders of the respiratory system have not been previously described in patients with X-linked adrenoleukodystrophy.

CASE PRESENTATION

A 3-year-old Arabic boy from Yemen presented with discoloration of the mucous membranes and nail beds, which were considered cyanoses due to methemoglobinemia. He also had shortness of breath, fatigue, emesis and dehydration episodes for which he was admitted to our hospital. Chest radiograph and chest computed tomography scans showed congenital pulmonary adenomatoid malformation. A few weeks before the removal of the malformation, he had a significant episode of hypotension and hypoglycemia. This development required further in-hospital evaluation that led to the diagnosis of adrenal insufficiency and the initiation of treatment with corticosteroids. One year later, he developed seizures and loss of consciousness. Magnetic resonance imaging of his head showed diffuse demyelination secondary to X-linked adrenoleukodystrophy. He was treated with anti-seizure and anti-oxidants, and was referred for bone marrow transplant evaluation.

CONCLUSION

The presence of adrenal insufficiency, neurologic deficits and seizures are common manifestations of X-linked adrenoleukodystrophy. The association of congenital lung disease with X-linked adrenoleukodystrophy or Addison's disease has not been described previously.