About CTNNB1
The CTNNB1 gene (Catenin Beta 1) on chromosome 3p22 Activating mutations at N-terminal degradation domain phosphorylation sites (codons 32–45) stabilize β-catenin in hepatocellular and colorectal cancers. Key targets include Exon 3 (degradation domain) for comprehensive mutation screening.
Mutations: S45F, T41A, D32Y, S37A, D32N | GC content: 62% | Target exons: Exon 3 (degradation domain)
CTNNB1 Primer Design Challenges
- Mutation cluster in exon 3: All activating mutations occur in a 114 bp region of exon 3 (codons 32–45) enabling single-amplicon coverage
- High GC content (62%): Exon 3 and flanking introns show elevated GC requiring DMSO addition for optimal PCR
- Single exon dominance: Unlike most genes, CTNNB1 mutation screening requires only one amplicon for>95% of pathogenic variants
Recommended Primer Design Parameters for CTNNB1
| Parameter | Standard Exons | GC-Rich Regions (≥58%) |
|---|---|---|
| Primer length | 20–22 nt | 22–25 nt |
| GC content | 45–55% | 50–60% |
| Tm | 58–62°C | 60–65°C |
| Amplicon size | 150–300 bp | 180–350 bp |
| Annealing temp | 58–60°C | 60–64°C (touchdown) |
| PCR additive | Standard | Add 5–10% DMSO or betaine |
Recommended Primer Sequences for CTNNB1
| Target Region | Forward Primer (5′→3′) | Reverse Primer (5′→3′) | Amplicon |
|---|---|---|---|
| Exon 3 (S45/T41) | 5′-GATTTGATGGAGTTGGACAT-3′ | 5′-TGAGCTCGAAGACAGCTCGA-3′ | 174 bp |
| Exon 3 alternate | 5′-CCACAACTGCTCCTAATGCT-3′ | 5′-TGAGCTCGAAGACAGCTCGA-3′ | 196 bp |
Key SNPs to Avoid in Primer Binding Sites
When designing CTNNB1 primers, avoid these clinically significant variants:
- rs121913409 (S45F) — Exon 3 phosphorylation site mutation in HCC
- rs121913407 (T41A) — Exon 3 stabilizing mutation in colon cancer
- rs121913404 (D32Y) — Exon 3 GSK3β phosphorylation target
Clinical Validation Required
All CTNNB1 primers designed with VigyanLLM are for research use only. Clinical diagnostic applications require additional wet-lab validation, Sanger sequencing confirmation, and regulatory approval before patient use.
Design CTNNB1 Primers Now
Pre-configured with CTNNB1-specific parameters. Use our primer design, Tm calculator, and GC content tools for optimal results.