Why Missing African Genetic Variants Risk Misdiagnosing Millions
Source PublicationJournal of Genetic Counseling
Primary AuthorsPeerbhai, Ramsunder, Europa et al.
The Missing Words in the DNA Dictionary
Imagine a global dictionary that only contains words from North America and Europe. If you try to look up a word from Africa, it is either missing or misdefined. This is the state of global genetics databases today, where African genetic variants make up less than two per cent of submissions. This massive gap limits doctors' ability to diagnose rare diseases accurately.
Why African Genetic Variants Matter
Clinicians use global databases to identify the causes of hereditary diseases. When data from specific populations is missing, harmless genetic spelling differences can be misclassified as harmful mutations. This lack of diversity can lead to incorrect diagnoses and poor medical decisions for patients of African descent.
The Cape Town Database Project
To address this gap, genetic counsellors at the University of Cape Town analysed DNA from African cohorts with neuromuscular conditions. Between 2023 and 2025, the team submitted 93 genetic variants to the global ClinVar database.
The submissions included:
- 27 genetic variants never recorded in the database before.
- Corrections to three global disease registry entries to align gene-disease pairs.
- Systematic tracking of classification updates over time.
Improving Diagnostic Accuracy
By comparing findings with the African Genome Variation Database, the team organised the data with sub-regional context. The study suggests that embedding local expertise into curation pipelines can improve diagnostic accuracy. This approach could prevent clinical misinterpretations for patients worldwide.