Late diagnosis of fucosidosis in a child with progressive fixed dystonia, bilateral pallidal lesions and red spots on the skin

An unusual presentation of fucosidosis in a Chinese boy: a case report and literature review (childhood fucosidosis)

Background

Fucosidosis is one of the rare autosomal recessive lysosomal storage diseases (LSDs) attributed to FUCA1 variants causing the deficiency of α-L-fucosidase in vivo. Α-L-fucosidase deficiency will cause excessive accumulation of fucosylated glycoproteins and glycolipids, which eventually leads to dysfunction in all tissue systems and presents with multiple symptoms. Fucosidosis is a rare disease which is approximately 120 cases have been reported worldwide (Wang, L. et al., J Int Med Res 48, 1-6, 2020). The number of reported cases in China is no more than 10 (Zhang, X. et al., J Int Med Res 49:3000605211005975, 2021).

Case presentation

The patient was an 8-year-old Chinese boy who presented with postnatal motor retardation, intellectual disability, short stature, language development retardation, coarse facial features, hepatomegaly, and diffuse angiokeratoma of both palms. His genetic testing showed the presence of a homozygous pathogenic variant (c.671delC) in the FUCA1 gene. In addition, the enzymatic activity of α-L-fucosidase was low. Ultimately, the patient was diagnosed with fucosidosis.

Conclusions

Fucosidosis is a rare lysosomal storage disease because of FUCA1 variants that cause the deficiency of α-L-fucosidase in vivo. An explicit diagnosis requires a combination of clinical manifestations, imaging examination, genetic testing and enzyme activity analysis. Early diagnosis plays an important role in fucosidosis.

Eye of the Tiger: Looking Beyond Neurodegeneration with Brain Iron Accumulation Disorders

The “eye-of-the-tiger” sign in brain magnetic resonance imaging (MRI) is typically associated with neurodegeneration with brain iron accumulation disorders, especially pantothenate kinase-associated neurodegeneration. However, very similar neuroimaging findings may be seen in other neurodegenerative disorders involving the basal ganglia. We report here a patient with fucosidosis who had MRI brain findings closely resembling the “eye-of-the-tiger” sign.

Ferroptosis and Its Modulation by Autophagy in Light of the Pathogenesis of Lysosomal Storage Diseases

Ferroptosis is one of the recently described types of cell death which is dependent on many factors, including the accumulation of iron and lipid peroxidation. Its induction requires various signaling pathways. Recent discovery of ferroptosis induction pathways stimulated by autophagy, so called autophagy-dependent ferroptosis, put our attention on the role of ferroptosis in lysosomal storage diseases (LSD). Lysosome dysfunction, observed in these diseases, may influence ferroptosis efficiency, with as yet unknown consequences for the function of cells, tissues, and organisms, due to the effects of ferroptosis on physiological and pathological metabolic processes. Modulation of levels of ferrous ions and enhanced oxidative stress, which are primary markers of ferroptosis, are often described as processes associated with the pathology of LSD. Inhibition of autophagy flux and resultant accumulation of autophagosomes in neuronopathic LSD may induce autophagy-dependent ferroptosis, indicating a considerable contribution of this process in neurodegeneration. In this review article, we describe molecular mechanisms of ferroptosis in light of LSD, underlining the modulation of levels of ferroptosis markers in these diseases. Furthermore, we propose a hypothesis about the possible involvement of autophagy-dependent ferroptosis in these disorders.

Fucosidosis in a Chinese boy: a case report and literature review

Fucosidosis is a rare lysosomal storage disease, resulting from a deficiency in an alpha-l-fucosidase enzyme. There are fewer than 120 cases of this disease worldwide and very few reported in Chinese children. Here, we report a Chinese boy presenting with psychomotor regression, dermatological abnormality, dysostosis multiplex, and classic changes observed with head magnetic resonance imaging. He was diagnosed with fucosidosis, with a previously reported homozygous mutation of c.393(exon2)T > A, p.Tyr131Stop, in the FUCA1 gene. Increasing awareness of fucosidosis will help in the early diagnosis of this disease and could shed light on the therapeutic role of hematopoietic stem cell transplantation, which may be effective in early stages of the disease.

A Proposed Diagnostic Algorithm for Inborn Errors of Metabolism Presenting With Movements Disorders

Inherited metabolic diseases or inborn errors of metabolism frequently manifest with both hyperkinetic (dystonia, chorea, myoclonus, ataxia, tremor, etc.) and hypokinetic (rigid-akinetic syndrome) movement disorders. The diagnosis of these diseases is in many cases difficult, because the same movement disorder can be caused by several diseases. Through a literature review, two hundred and thirty one inborn errors of metabolism presenting with movement disorders have been identified. Fifty-one percent of these diseases exhibits two or more movement disorders, of which ataxia and dystonia are the most frequent. Taking into account the wide range of these disorders, a methodical evaluation system needs to be stablished. This work proposes a six-step diagnostic algorithm for the identification of inborn errors of metabolism presenting with movement disorders comprising red flags, characterization of the movement disorders phenotype (type of movement disorder, age and nature of onset, distribution and temporal pattern) and other neurological and non-neurological signs, minimal biochemical investigation to diagnose treatable diseases, radiological patterns, genetic testing and ultimately, symptomatic, and disease-specific treatment. As a strong action, it is emphasized not to miss any treatable inborn error of metabolism through the algorithm.

Mitochondrial Dysfunction, Oxidative Stress and Neuroinflammation in Neurodegeneration with Brain Iron Accumulation (NBIA)

The syndromes of neurodegeneration with brain iron accumulation (NBIA) encompass a group of invalidating and progressive rare diseases that share the abnormal accumulation of iron in the basal ganglia. The onset of NBIA disorders ranges from infancy to adulthood. Main clinical signs are related to extrapyramidal features (dystonia, parkinsonism and choreoathetosis), and neuropsychiatric abnormalities. Ten NBIA forms are widely accepted to be caused by mutations in the genes PANK2, PLA2G6, WDR45, C19ORF12, FA2H, ATP13A2, COASY, FTL1, CP, and DCAF17. Nonetheless, many patients remain without a conclusive genetic diagnosis, which shows that there must be additional as yet undiscovered NBIA genes. In line with this, isolated cases of known monogenic disorders, and also, new genetic diseases, which present with abnormal brain iron phenotypes compatible with NBIA, have been described. Several pathways are involved in NBIA syndromes: iron and lipid metabolism, mitochondrial dynamics, and autophagy. However, many neurodegenerative conditions share features such as mitochondrial dysfunction and oxidative stress, given the bioenergetics requirements of neurons. This review aims to describe the existing link between the classical ten NBIA forms by examining their connection with mitochondrial impairment as well as oxidative stress and neuroinflammation.

Diagnosis and Supportive Management of Fucosidosis: A Case Report

Fucosidosis is a lysosomal storage disease, resulting from a deficiency of the enzyme alpha-L-fucosidase. We present the case of an affected female with numerous manifestations, clinically and radiographically. In fucosidosis, advanced interventions are not always necessary to have rewarding outcomes. In fact, early diagnosis and management of the symptoms with a multi-systemic supportive care approach can improve the quality of life and may also prolong the life of those patients diagnosed with fucosidosis.

Ocular findings in a patient with fucosidosis

Purpose

To describe the ocular findings in a patient with fucosidosis, a rare inborn lysosomal storage disease.

Observations

A 14 year-old female presented with angiokeratomas corporis diffusum, coarse facial features, poor verbal skills, hearing impairment and mild developmental delay. A lysosomal storage enzyme screen confirmed absent activity of α-l-fucosidase consistent with a diagnosis of fucosidosis. Her eye exam was remarkable for telangiectatic vessels in the inferior conjunctiva and mild corneal stromal haze bilaterally. Spectral domain–optical coherence tomography scans of the macula and a full-field electroretinogram were normal.

Conclusions and importance

We describe the findings in a 14 year-old patient with fucosidosis and review the systemic and ocular manifestations of this rare lysosomal storage disease.

Neurometabolic disorders are treatable causes of dystonia

A broad range of rare inherited metabolic disorders can present with dystonia. For clinicians, it is important to recognize dystonic features, but it can be complicated by the mixed and complex clinical picture seen in many neurometabolic patients. Careful phenotyping is the first step towards the diagnosis of the underlying condition and subsequent targeted treatment, further supported by imaging, biochemical diagnostics and the availability of modern diagnostic techniques such as next generation sequencing. As several neurometabolic disorders are treatable causes of dystonia, these should have priority in the diagnostic process. In the symptomatic treatment of dystonia, several therapeutic options are available. Awareness for the occurrence and optimal treatment of dystonia and other movement disorders in neurometabolic conditions is important because these symptoms can have a substantial impact on the quality of life and daily functioning; this effect is not only exerted by the dystonia itself, but also by the frequently associated non-motor features. In this paper, the highlights and key concepts of neurometabolic forms of dystonia are discussed, with a focus on phenomenology, the diagnostic approach, the most important neurometabolic aetiologies, co-occurring non-motor features and therapeutic options.

Clinical and neuroradiological approach to fucosidosis in a child with atypical presentation

Fucosidosis is a rare lysosomal storage disease with clinical presentation of developmental retardation, coarse facial features, hepatosplenomegaly, dysostosis multiplex, and angiokeratomas. Here, a 7-year-old female patient with progressive dystonic movement disorder and loss of acquired motor skills is presented. Coarse facial feature and abnormal globuspallidus signaling in brain magnetic resonance imaging (MRI) led the patient to be investigated in terms of fucosidosis despite absence of hepatosplenomegaly, dysostosis multiplex, and angiokeratomas. Markedly decreased enzyme activity of alpha-fucosidosis led to the correct diagnosis.