Laboratory for Molecular Diagnostics
Center for Nephrology and Metabolic Disorders

Alpha-galactosidase A

The alpha-galactosidase A, an enzyme to degrade ceramid into removable compounds, is found in lysosoms. Accumulation of not digestable metabolites results in Fabry disease.

Epidemiology

The prevalance of mutations is from 0,2 per 100.000 in Netherlands up to 0,9 in Australia.

Gene Structure

The GLA gene is about 10kb in size. It is located on X-chromosom (Xq22.1). Mutation relevant for Fabry's disease can be fount on all of the 7 exons.

Phenotype

Hemizygous male patients develop the full blown disease females that are heterozygous develop only few symptomes. Clincal manifestation starts in early adult age. Some patients develop end stage renal disease.

Pathology

The enzyme is glycosilated. It forms a homodimer. The different types known so far differ in there extend of glycosilation. The enzyme has an important function in cell membrane turn over. It is located in lysosomes degradates here glycosphingolipids. If not degredated these substances accumulate in many organs to result in dysfunction. This takes place in epithelial cells, in glomeruli and tubuli of the kidney, in heart muscel cells, in cells of the ganglions of the peripheral nervous system and in the cornea.

Test Strategy

Patients where biochemical data and family history is suspect for Fabry's diesease.

Interpretation

The verification of a mutation is equivalent to a strong confirmation of the diagnosis. Often new mutations will be found. There is a correlation between mutation and clinical picture. The therpy is available.

Genetests:

Clinic Method Carrier testing
Turnaround 5 days
Specimen type genomic DNA
Clinic Method Massive parallel sequencing
Turnaround 25 days
Specimen type genomic DNA
Clinic Method Genomic sequencing of the entire coding region
Turnaround 20 days
Specimen type genomic DNA
Clinic Method Multiplex Ligation-Dependent Probe Amplification
Turnaround 20 days
Specimen type genomic DNA

Related Diseases:

Fabry disease
GLA

References:

1.

Grünfeld JP et al. (2002) Anderson-Fabry disease: its place among other genetic causes of renal disease.

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2.

Pastores GM et al. (2002) Biochemical and molecular genetic basis of Fabry disease.

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3.

Branton M et al. (2002) Natural history and treatment of renal involvement in Fabry disease.

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4.

Orphanet article

Orphanet ID 122153 [^]
5.

NCBI article

NCBI 2717 [^]
6.

OMIM.ORG article

Omim 300644 [^]
7.

Wikipedia article

Wikipedia EN (Fabry_disease) [^]
Update: April 29, 2019