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

A case of type II fucosidosis-diagnosed with neuroradiological and dysmorphological findings

The Article Abstract is not available.

Lysosomal storage diseases in the era of COVID-19: a report of an Egyptian case of alpha-fucosidosis and a summary of the lysosomal storage diseases-COVID-19 relationship

Background

We present a case of alpha-fucosidosis, a lysosomal storage disorder, from Egypt. The report also includes a brief review of the COVID-19 and lysosomal storage diseases relationship.

Case presentation

A female patient aged 18 years, diagnosed with type II fucosidosis, based on the cutaneous signs, characteristic facies, and systemic symptoms, and diagnosis was confirmed using genetic analysis. The patient died from COVID-19 pneumonia during the COVID-19 pandemic after getting the infection from her father and being hospitalized.

Conclusions

Patients with lysosomal storage diseases with local or systemic immune suppression may be predisposed to respiratory complications of COVID-19. Intense care with protective guidelines should be applied to those patients.

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.

Clinical and Genetic Characteristics of Chinese Children With GLUT1 Deficiency Syndrome: Case Report and Literature Review

Objective: GLUT1 deficiency syndrome (GLUT1-DS) is a rare, treatable neurometabolic disorder. However, its diagnosis may be challenging due to the various and evolving phenotypes. Here we report the first Chinese familial cases with genetically confirmed GLUT1-DS and analyze the characteristics of Chinese children with GLUT1-DS from clinical, laboratory, and genetic aspects.

Methods: We reported a Chinese family with three members affected with GLUT1-DS and searched for relevant articles up to September 2020 from PubMed, WOS, CNKI, and WanFang databases. A total of 30 Chinese patients diagnosed with GLUT1-DS (three newly identified patients in one family and 27 previously reported ones) were included and analyzed in this study.

Results: The median age of onset of the 30 patients (male: 18, female: 12) was 8.5 months (range, 33 days to 10 years). Epileptic seizures were found in 25 patients, most with generalized tonic–clonic and focal ones. Movement disorders were found in 20 patients—frequently with ataxia and dystonia, developmental delay in 25 patients, and microcephaly only in six patients. The cerebrospinal fluid (CSF) analysis showed decreased CSF glucose (median: 1.63 mmol/L, range: 1.1–2.6 mmol/L) and glucose ratio of CSF to blood (median: 0.340; range: 0.215–0.484). The genetic testing performed in 28 patients revealed 27 cases with pathogenic variations of the SLC2A1 gene, including 10 missense, nine frameshift, three nonsense, three large fragment deletions, and two splice-site mutations. Most patients had a good response to the treatment of ketogenic diet or regular diet with increased frequency. Although three patients in this Chinese family carried the same pathogenic mutation c.73C > T (p.Q25X) in the SLC2A1 gene, their symptoms and responses to treatment were not exactly the same.

Conclusion: The clinical manifestations of GLUT1-DS are heterogeneous, even among family members sharing the same mutation. For children with unexplained epileptic seizures, developmental delay, and complex movement disorders, detection of low CSF glucose or SLC2A1 gene mutations is helpful for the diagnosis of GLUT1-DS. Early initiation of ketogenic diet treatment significantly improves the symptoms and prognosis of GLUT1-DS.

Identification of a novel homozygous loss-of-function mutation in FUCA1 gene causing severe fucosidosis: A case report

Fucosidosis is a rare lysosomal storage disorder characterized by deficiency of α-L-fucosidase with an autosomal recessive mode of inheritance. Here, we describe a 4-year-old Chinese boy with signs and symptoms of fucosidosis but his parents were phenotypically normal. Whole exome sequencing (WES) identified a novel homozygous single nucleotide deletion (c.82delG) in the exon 1 of the FUCA1 gene. This mutation will lead to a frameshift which will result in the formation of a truncated FUCA1 protein (p.Val28Cysfs*105) of 132 amino acids approximately one-third the size of the wild type FUCA1 protein (466 amino acids). Both parents were carrying the mutation in a heterozygous state. This study expands the mutational spectrum of the FUCA1 gene associated with fucosidosis and emphasises the benefits of WES for accurate and timely clinical diagnosis of this rare disease.

The Identification of a Novel Fucosidosis-Associated FUCA1 Mutation: A Case of a 5-Year-Old Polish Girl with Two Additional Rare Chromosomal Aberrations and Affected DNA Methylation Patterns

Fucosidosis is a rare neurodegenerative autosomal recessive disorder, which manifests as progressive neurological and psychomotor deterioration, growth retardation, skin and skeletal abnormalities, intellectual disability and coarsening of facial features. It is caused by biallelic mutations in FUCA1 encoding the α-L-fucosidase enzyme, which in turn is responsible for degradation of fucose-containing glycoproteins and glycolipids. FUCA1 mutations lead to severe reduction or even loss of α-L-fucosidase enzyme activity. This results in incomplete breakdown of fucose-containing compounds leading to their deposition in different tissues and, consequently, disease progression. To date, 36 pathogenic variants in FUCA1 associated with fucosidosis have been documented. Among these are three splice site variants. Here, we report a novel fucosidosis-related 9-base-pair deletion (NG_013346.1:g.10233_10241delACAGGTAAG) affecting the exon 3/intron 3 junction within a FUCA1 sequence. This novel pathogenic variant was identified in a five-year-old Polish girl with a well-defined pattern of fucosidosis symptoms. Since it is postulated that other genetic, nongenetic or environmental factors can also contribute to fucosidosis pathogenesis, we performed further analysis and found two rare de novo chromosomal aberrations in the girl’s genome involving a 15q11.1-11.2 microdeletion and an Xq22.2 gain. These abnormalities were associated with genome-wide changes in DNA methylation status in the epigenome of blood cells.

Fucosidosis-Clinical Manifestation, Long-Term Outcomes, and Genetic Profile-Review and Case Series

Fucosidosis is a neurodegenerative disorder which progresses inexorably. Clinical features include coarse facial features, growth retardation, recurrent upper respiratory infections, dysostosis multiplex, and angiokeratoma corporis diffusum. Fucosidosis is caused by mutations in the FUCA1 gene resulting in α-L-fucosidase deficiency. Only 36 pathogenic variants in the FUCA1 gene are related to fucosidosis. Most of them are missense/nonsense substitutions; six missense and 11 nonsense mutations. Among deletions there were eight small and five gross changes. So far, only three splice site variants have been described—one small deletion, one complete deletion and one stop-loss mutation. The disease has a significant clinical variability, the cause of which is not well understood. The genotype–phenotype correlation has not been well defined. This review describes the genetic profile and clinical manifestations of fucosidosis in pediatric and adult cases.