Establishment of a New-Generation National Reference Material System for Fragile X Syndrome Using Targeted Long-Read...

Area of Science:

• Genetics
• Molecular Biology
• Medical Diagnostics

Background:

• Fragile X syndrome (FXS) is a leading inherited intellectual disability cause.
• CGG repeat expansion in the FMR1 gene underlies FXS.
• Current diagnostic methods lack precision for long repeats and AGG interruptions, hindering risk assessment.

Purpose of the Study:

• To develop a precise assay for comprehensive FMR1 gene characterization.
• To improve Fragile X syndrome molecular diagnostics and risk assessment.
• To establish advanced national reference materials for FXS.

Main Methods:

• Development of a targeted long-read sequencing assay (tLRS-FMR1).
• Application of the assay to 22 national FXS reference materials.
• Validation against conventional diagnostic methods.

Main Results:

• The tLRS-FMR1 assay achieved 100% concordance with standard methods.
• Precise quantification of CGG repeats and mapping of AGG interruptions were enabled.
• High reproducibility and a low detection limit (3 ng/μL) were demonstrated.

Conclusions:

• Successful development of the tLRS-FMR1 assay.
• Establishment of a new generation of national FXS reference materials with enhanced molecular data.
• Foundation laid for improved standardization and accuracy in FXS molecular diagnosis.