A Novel Homozygous Mutation in the FUCA1 Gene Highlighting Fucosidosis as a Cause of Dystonia: Case Report and Literature Review.

BACKGROUND: Fucosidosis is a rare lysosomal disorder caused by mutations in the FUCA1 gene. We describe here a novel homozygous mutation in FUCA1 in an Indian fucosidosis case. Furthermore, we summarize the clinical and genetic findings in the most recently reported individuals with fucosidosis. CASE: The proband is an 8-year-old boy born to consanguineous parents. He had generalized dystonia and bilateral spasticity as well as coarse facies, dysostosis multiplex, recurrent infections, angiokeratoma corporis diffusum, and visceromegaly. Whole exome sequencing analysis detected a homozygous canonical splice variant in the FUCA1 gene [Chr1(GRCh37):g.24172346C > T; NM_000147.4:c.1261-1G > A], not previously reported as causative of a human phenotype. Low levels of α-fucosidase in patient leukocytes and a positive qualitative urine based thin layer chromatography test for fucosidosis confirmed the diagnosis. Our literature review identified 89 cases of fucosidosis since the last major review. We show that dystonia is a rare manifestation (12%) and that only a small minority of cases receive treatment with transplantation (3.37%). CONCLUSION: We report a novel homozygous mutation in FUCA1 as the cause of severe neurological phenotype including generalized dystonia. Early recognition of fucosidosis may be important for consideration of promising treatment options, such as bone marrow transplantation.

Transcriptomic analysis of FUCA1 knock-down in keratinocytes reveals new insights into the pathogenesis of fucosidosis skin lesions.

Fucosidosis is a rare lysosomal storage disease which has been classified into two subtypes, depending on the severity of clinical signs and symptoms. Fucosidosis patients' skin abnormalities include angiokeratoma corporis diffusum, widespread telangiectasia, thick skin, hyperhidrosis and hypohidrosis, acrocyanosis and distal transverse nail bands. It has been described that >50% of fucosidosis patients have angiokeratoma. At molecular level, fucosidosis is caused by lysosomal alpha-L-fucosidase (FUCA1) gene mutations. Obtaining samples for functional studies has been challenging due to the inherent difficulty in finding affected individuals. The effect of FUCA1 dysfunction on gene expression is unknown. The aim of this study was to analyse, in keratinocytes, the transcriptomic effect of FUCA1 knock-down for a better understanding of skin lesions' pathogenesis affecting fucosidosis patients. FUCA1 knock-down (siRNA) was performed in human HaCaT immortalised keratinocytes. Affymetrix arrays and qPCR were used for analysing gene expression. Bioinformatics was used for functional clustering of modified genes. In total, 387 genes showed differential expression between FUCA1 silenced and non-silenced cells (222 up-regulated and 165 down-regulated). Up-regulated genes belonged to two major groups: keratinocyte differentiation/epidermal development (n = 17) and immune response (n = 61). Several transcription factors were up-regulated in FUCA1-siRNA transfected cells. This effect might partly have been produced by abnormal transcription factor expression, that is FOXN1. We thus propose that fucosidosis-related skin lesions (eg angiokeratoma) and those of other diseases (eg psoriasis) might be caused by dysfunctions in common aetiological overlapping molecular cascades.

Recalcitrant chronic rhinosinusitis in the setting of fucosidosis, a rare lysosomal storage disorder.

Fucosidosis is an autosomal recessive lysosomal storage disorder caused by the deficiency of alpha-L-fucosidase. We present the case of an affected female in the second decade of life with chronic rhinosinusitis (CRS) including recalcitrant polypoid inflammation, which has not been previously reported in the literature. With the advancement of life-prolonging measures, children with lysosomal storage disorders may suffer increasingly from CRS due to the lymphohistiocytic and macrophage infiltrate of the paranasal sinus mucosa that resembles severe polypoid inflammation.

Skeletal and Brain Abnormalities in Fucosidosis, a Rare Lysosomal Storage Disorder.

Fucosidosis is a rare genetic lysosomal storage disorder caused by a deficiency in alpha- L-fucosidase. We present a case of a 4-year, 11-month-old girl with developmental delay, as well as skeletal and brain abnormalities as shown on X-ray and MRI. Her spinal X- rays demonstrated lumbar kyphosis and anterior beaking of lumbar vertebral bodies. Lower iliac segment constriction, increased angulation of the acetabular roof, and widening of the ribs were apparent on abdominal X-ray. Her brain MRI illustrated symmetric T1 hyperintensity and T2 hypointensity of the bilateral globi pallidi. The case report highlights clinical and imaging findings of this rare disease.

Oligodendrocyte loss during the disease course in a canine model of the lysosomal storage disease fucosidosis.

Hypomyelination is a poorly understood feature of many neurodegenerative lysosomal storage diseases, including fucosidosis in children and animals. To gain insight into hypomyelination in fucosidosis, we investigated lysosomal storage, oligodendrocyte death, and axonal and neuron loss in CNS tissues of fucosidosis-affected dogs aged 3 weeks to 42 months using immunohistochemistry, electron microscopy, and gene expression assays. Vacuole accumulation in fucosidosis oligodendrocytes commenced by 5 weeks of age; all oligodendrocytes were affected by 16 weeks. Despite progressive vacuolation, mature oligodendrocyte loss by apoptosis (caspase-6 positive) in the corpus callosum and cerebellar white matter stabilized by 16 weeks, with no further subsequent loss. Axonal neurofilament loss progressed only in late disease, suggesting that disturbed axon-oligodendrocyte interactions are unlikely to be the primary cause of hypomyelination. A 67% decline in the number of Purkinje cell layer oligodendrocytes coincided with a 67% increase in the number of caspase-6-positive Purkinje cells at 16 weeks, suggesting that early oligodendrocyte loss contributes to Purkinje cell apoptosis. Fucosidosis hypomyelination appeared to follow normal spatiotemporal patterns of myelination, with greater loss of oligodendrocytes and larger downregulation of CNP, MAL, and PLP1 genes at 16 weeks in the cerebellum versus the frontal cortex. These studies suggest that survival of oligodendrocytes in fucosidosis is limited during active myelination, although the mechanisms remain unknown.

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

Fucosidosis is a rare lysosomal storage disease. A 14-year-old girl is presented, with recurrent infections, progressive dystonic movement disorder and mental retardation with onset in early childhood. The clinical picture was also marked by mild morphologic features, but absent dysostosis multiplex and organomegaly. MRI images at 6.5 years of age were reminiscent of pallidal iron deposition ("eye-of-the-tiger" sign) seen in neurodegeneration with brain iron accumulation (NBIA) disorders. Progressively spreading angiokeratoma corporis diffusum led to the correct diagnosis. This case extends the scope of clinical and neuroradiological manifestations of fucosidosis.

Hypomyelination with T2-hypointense globi pallidi in a child with fucosidosis.

A 4-year-old boy presented with progressive neurodegeneration, mild coarsening of facies and spasticity. The classical neuroimaging guided the subsequent investigation of enzyme assay which confirmed the diagnosis of fucosidosis.

Mutation identification of Fabry disease in families with other lysosomal storage disorders.

Fabry disease (FD) is an X-linked lysosomal storage disorder (LSD) caused by the deficiency of the enzyme α-galactosidase. It exhibits a wide clinical spectrum that may lead to a delayed or even missed diagnosis and the real incidence can be underestimated. We report the cases of two unrelated Italian families in whom FD was incidentally diagnosed in two females. In both families, the risk for other lysosomal disorders was known from other members affected by fucosidosis or mucopolysaccharidosis I Hurler/Scheie. Some subjects were simultaneously heterozygous for Fabry and the other lysosomal deficiency. Our study shows that the risk for more than one LSDs can occur in a family pedigree. The diagnosis of Fabry in female probands represents a diagnostic challenge, as symptoms and signs can be variably present because of the random X-chromosome inactivation.

Lysosomal disorders associated with leukoencephalopathy.

Metachromatic leukodystrophy and Krabbe's disease are among the most widely recognized causes of leukodystrophy. However, white matter changes have been described in several other lysosomal storage disorders. These conditions are summarized and those associated with hypomyelination are reviewed in more detail.

[The child with a known metabolic disease: anaesthetic management]. / L'enfant souffrant d'une maladie métabolique connue: stratégie anesthésique.

The anaesthetic management of a child with a known metabolic disease is always a challenge. It should be a multidisciplinary process based upon the experience of all medical specialists involved and on a thorough review of the information available in the literature and in specialized up to date websites. The authors propose a list of questions to be addressed when dealing with such a case and provide two clinical examples.

Severe hypomyelination as the leading neuroradiological sign in a patient with fucosidosis.

Fucosidosis is a rare autosomal recessive lysosomal storage disease, resulting from a deficiency of alpha- L-fucosidase. We report on the clinical and MRI findings of a girl with this disorder. Developmental delay became obvious at an age between 6 and 12 months. Cranial MRI at 16 months revealed severe global hypomyelination of both supra- and infratentorial white matter but no involvement of basal ganglia or thalamus. No clinical signs typical for fucosidosis were present at this time, and psychomotor development still progressed slowly. Since the age of 2 years, progressive neurological deterioration occurred. The diagnosis was established by severely decreased activity of alpha- L-fucosidase in plasma and leukocytes and confirmed by the detection of compound heterozygosity for two missense mutations of the FUCA1 gene. A follow-up imaging at the age of 4 years showed progression of neuroradiological abnormalities, particularly progressive involvement of basal ganglia and thalami. The course of this patient and her MRI findings enlarge the clinical and neuroradiological spectrum of fucosidosis.

Fucosidosis with angiokeratoma. Immunohistochemical & electronmicroscopic study of a new case and literature review.

Fucosidosis is a rare lysosomal storage disease due to alpha-L-fucosidase deficiency. It presents clinically with neurological, skeletal, and cutaneous findings, including mainly angiokeratoma corporis diffusum. Electronmicroscopic examination reveals characteristic electron-lucent cytoplasmic vacuolization present in several cell types of the skin and other tissues. We present here a new patient suffering from fucosidosis with angiokeratoma, whose normal and diseased skin was studied by lightmicroscopy and electronmicroscopy. The salient clinicopathological features of this disease are briefly reviewed.

Fucosidosis with hypothyroidism: a case report.

Fucosidosis is a rare, autosomal recessive lysosomal storage disorder caused by a severe deficiency of alpha-L-fucosidase. Here we present a 27-month-old male who was referred to us for evaluation of developmental delay, which was first detected at age six months. His past medical history was also remarkable for recurrent pulmonary infections and myoclonic seiures. His family history revealed that he was the first living child from a consanguineous marriage. He had a younger sister who died at five months of age from pneumonia who had facial resemblance to the proband, developmental delay and a congenital heart defect. Physical examination revealed length: 81 cm (25-50p), weight: 10.2 kg (25-50p), and head circumference: 49 cm (50-75p). He had a coarse face, hepatomegaly and generalized spasticity. His initial laboratory examination revealed negative urine screening column chromatography for mucopolysaccharidosis. His X-ray findings were consistent with mild form of dysostosis multiplex. Based on clinical and laboratory features, fucosidosis was suspected. Fucosidase enzyme activity was zero. In addition to fucosidosis, thyroid function tests indicated primary hypothyroidism. This is, to the best of our knowledge, the fourth case of fucosidosis diagnosed in Turkey.

Four year follow-up of a case of fucosidosis treated with unrelated donor bone marrow transplantation.

Fucosidosis is a rare autosomal recessive lysosomal disorder caused by alpha-fucosidase deficiency. We report a child with fucosidosis, second daughter of non-consanguineous parents, for whom biochemical diagnosis followed clinical evidence of the disease in her older sister. Based on previous experiences, the indication to transplant was considered. Since she lacked a matched sibling, an unrelated marrow donor was found. At pre-hematopoietic stem cell transplantation evaluation, first signs of neurological involvement were clinically detectable. MRI showed diffuse hypomyelination and auditory brainstem responses and somatic-sensorial evoked potentials were altered. Visual evoked potentials were normal, tortuosity in the retinal veins and peripapillary hemorrhages were detected. Bone marrow transplantation conditioning was with a regimen of busulphan, thiotepa and cyclophosphamide; in vivo Campath 1G, cyclosporin A and short course methotrexate were given to prevent graft-versus-host disease. The patient engrafted rapidly and her post-transplant course was complicated by moderate graft-versus-host disease, transient episodes of idiopathic thrombocytopenic purpura, repeated septic complications and recurrent episodes of Sweet's syndrome. Sequential short tandem repeat polymorphisms on peripheral blood and bone marrow cells documented the persistence of donor engraftment. Follow-up showed a progressive rise of enzymatic levels. Psychomotor development improved, as confirmed by evaluation of evoked potentials and by MRI scanning.

Cutaneous manifestations of fucosidosis.

Angiokeratoma corporis diffusum (ACD) is still often thought to be synonymous with Anderson-Fabry disease, a deficiency of alpha-galactosidase. It is important, however, to consider other possible enzyme deficiencies in patients with ACD. We report an 8-year-old boy with neurodevelopmental delay who was diagnosed as having fucosidosis following recognition of ACD in the dermatology department. Other cutaneous features in this patient included distal transverse purple nail bands, acrocyanosis and a naevus anaemicus. Histology and electron microscopy of skin papules was consistent with angiokeratoma. Skeletal survey demonstrated dysostosis multiplex. The diagnosis was confirmed by leucocyte oligosaccharide enzyme analysis. There are only three previous reports of fucosidosis in the U.K.

Fucosidosis with dystonia.

Fucosidosis, a progressive neurodegenerative disease, evident in early childhood, is associated with progressive loss of mental and motor function and increasing spasticity and hyperreflexia. We report a Canadian male, with clinical features similar to previously reported fucosidosis patients, however, since age 5 he has exhibited progressive dystonic posturing, initially unilateral, but recently involving both lower limbs. Extensive study of his cultured lymphoblasts demonstrated that alpha-fucosidase activity and immunoreactive alpha-fucosidase protein were absent. He is homozygous for the Q422X mutation, a C to T transition within exon 8 of the alpha-fucosidase gene which results in loss of an EcoR1 restriction enzyme cut site. Even among the 4 other reported fucosidosis families having one or more individuals homozygous for this same (Q422X) mutation there was no previous report of dystonia.

[Angiokeratoma and fucosidosis. Immunohistochemical and ultrastructural study]. / Angiokératomes et fucosidose. Etude immunohistochimique et ultrastructurale.

INTRODUCTION: Angiokeratoma can lead to diagnoses other than Fabry's disease. We report a case of angiokeratoma in a child with fucosidosis. CASE REPORT: A 7-year-old child with psychomotor retardation presented angiokeratoma located on the penis. Uptake of type I Ulex Europaeus Agglutinin antilectin antiserum was intense in the endothelial structure. This antibody is specific for alpha-L-fucose residues which were thus found in large quantities in the vacuoles of the ultrastructure. The patient also had a major deficiency in leukocyte, serum and fibroblast alpha-fucosidase. COMMENTS: This is a typical case of fucosidosis, a rare hereditary disease with autosomal recessive transmission due to generalized deficiency in alpha-L-fucosidase. Diffuse angiokeratosis should suggest, other than Fabry's disease, fucosidase and other enzyme deficiencies including sialidase, GM1 gangliosidase as well as Kanzaki's disease.

Recurrent respiratory infections in a child with fucosidosis: is the mucus too thin for effective transport?

Fucosidosis is caused by a deficiency of the lysosomal enzyme alpha-L-fucosidase (ALF) leading to an accumulation of glycoproteins in a variety of cells. Infants and young children with this disorder are prone to recurrent sinus and pulmonary infections and often die of pneumonia. We studied the mucociliary and systemic immune function in a 6 year old girl with fucosidosis and recurrent respiratory infections. All measurements of systemic immune function were normal. Sweat chloride was normal when measured on angiokeratotic skin but was greater than 65 mg/L on uninvolved areas. During the placement of tympanic ventilation tubes, tracheal mucus was gently aspirated and a mucosal biopsy was taken. Tracheal mucus transport was not measured. The biopsy material was examined under phase contrast microscopy and revealed ciliated cells with apparently normal beating. TEM of these cells showed a characteristic pattern of vacuoles in the cytoplasm as described in other tissues from patients with fucosidosis. Ciliary ultrastructure was normal. Mucus viscoelasticity was measured in a magnetic microrheometer. The loss tangent was 2 SD above the mean for normal mucus and mechanical impedance was about 2 SD below the mean. These changes are similar in direction but double in magnitude to what has been described with methacholine administration in dogs. The high compliance of the mucus may be due to incomplete assembly of mucus glycoprotein or to decreased secretion of glycoproteins in respiratory secretions. This leads to mucus that is abnormally watery and thus difficult to clear from the airway.