Fucosidosis: four new mutations and a new polymorphism

Area of Science:

• Biochemistry
• Genetics
• Rare Diseases

Background:

• Fucosidosis is a rare lysosomal storage disorder characterized by a severe deficiency of alpha-L-fucosidase activity.
• The disorder results from mutations in the FUCA-1 gene, which encodes the alpha-L-fucosidase enzyme.

Purpose of the Study:

• To identify and characterize mutations in the FUCA-1 gene in patients with fucosidosis.
• To correlate identified mutations with clinical phenotypes and enzyme activity.

Main Methods:

• Amplification of all 8 exons of the FUCA-1 gene using PCR.
• Subcloning and sequencing of amplified PCR products.
• Restriction fragment length polymorphism (RFLP) analysis for haplotype determination.
• Pedigree analysis and prediction of mutation consequences on enzyme function.

Main Results:

• Four presumed disease-causing mutations in FUCA-1 were identified: a large deletion in Algerian siblings, E375X in Hispanic patients, G60D in Italian and French-American (Cajun) patients, and K151fs in an Italian patient.
• The G60D mutation creates a unique AflIII restriction site, and the K151fs mutation alters BstXI and BpmI sites.
• A common polymorphism (Q281R) was identified in exon 5, potentially linked to electrophoretic variants.

Conclusions:

• The identified mutations provide a molecular basis for fucosidosis in the studied patient cohorts.
• Genetic analysis of FUCA-1 is crucial for diagnosing fucosidosis and understanding its diverse molecular etiology.
• Further studies are needed to fully elucidate the functional impact of the Q281R polymorphism.