Lyso-Gb3 Indicates that the Alpha-Galactosidase A Mutation D313Y is not Clinically Relevant for Fabry Disease

Area of Science:

• Genetics and rare diseases
• Biochemistry and molecular diagnostics

Background:

• Fabry disease is an X-linked lysosomal storage disorder with potentially severe clinical outcomes.
• The D313Y mutation's clinical significance is uncertain, as patients often lack typical Fabry disease manifestations.
• Reduced alpha-galactosidase A enzyme activity is observed in D313Y mutation carriers.

Purpose of the Study:

• To conduct a comprehensive analysis of the D313Y mutation's clinical, biochemical, and molecular genetic aspects.
• To evaluate the D313Y mutation's classification as a classical or variant mutation in Fabry disease.

Main Methods:

• Clinical evaluation of two patients with the D313Y mutation.
• Biochemical analysis of alpha-galactosidase A activity.
• Measurement of the biomarker lyso-Gb3 levels.
• Molecular genetic analysis.

Main Results:

• Both patients exhibited reduced alpha-galactosidase A activity.
• Neither patient presented with clinical symptoms or organ involvement characteristic of Fabry disease.
• Lyso-Gb3 levels in both patients were below the average range observed in the normal population.

Conclusions:

• The D313Y mutation is biochemically and clinically distinct from classical Fabry disease mutations.
• This study provides evidence supporting the classification of D313Y as a rare variant mutation.
• Further research may clarify the precise role and implications of the D313Y mutation.