Definition
- CDKN2A gene
- Autosomal Dominant condition
- Reduced penetrance and variable expressivity
Genetics
- Linked to mutations in the CKDN2A gene on Chromosome 9
- CDKN2A gene:
- Cyclin dependent kinase inhibitor 2A gene
- Codes for 3 different tumor suppressors, including p16
- Also NRAS/BRAF
Clinical
- Causes a person to have a large number of naevi (Often > 100)
- With a propensity to become dysplastic
Sequele
- Associated with increased melanoma risk
- Some say 100% cumulative lifetime risk
- Vs 5% with Dysplastic Naevi only
Diagnostic Criteria
- 1 or more 1° or 2° relatives with melanoma
- Large number of naevi > 50
- Dysplastic Naevi on histology