Confirmation of Exome Sequencing Results Using Sanger Sequencing-Considerations in a Low-Resource Setting

Area of Science:

• Genomic Medicine
• Developmental Disorders
• Bioinformatics

Background:

• Exome sequencing (ES) is a primary diagnostic tool for developmental disorders (DD).
• International guidelines traditionally recommend orthogonal validation of ES findings, like Sanger sequencing.
• The DDD-Africa study addresses equitable genomic medicine implementation in low-resource African settings.

Purpose of the Study:

• To evaluate the necessity of confirmatory Sanger sequencing for exome sequencing variants in a low-resource setting.
• To assess the cost-benefit ratio of confirmatory testing in resource-limited environments.
• To facilitate the implementation of genomic medicine in Africa.

Main Methods:

• Performed Sanger sequencing for 70 variants in 64 probands with identified variants of interest from exome sequencing.
• Applied strict quality parameters to exome sequencing data to minimize false-positive variant identification.

Main Results:

• All 38 high-confidence variants from exome sequencing were confirmed by Sanger sequencing.
• All 32 low-confidence variants identified by exome sequencing were confirmed as false-positives.

Conclusions:

• Orthogonal validation of exome sequencing results using Sanger sequencing is redundant when robust, context-informed quality thresholds are applied.
• Eliminating confirmatory testing removes barriers to genomic medicine implementation.
• This approach accelerates global genomic access, particularly in resource-limited settings.