Reasoning
The BRAF VCEP requires point-based scoring for autosomal-dominant cases with RASopathy phenotypic specifications and assigns Supporting, Moderate, or Strong evidence at ≥1, ≥3, or ≥5 points. The reviewed exact-variant literature documents somatic cancer observations, including one D593G tumor in 164 non-Hodgkin lymphoma cases, one colorectal adenoma among 130 tumors, and eight tumors in a cancer cohort, but provides no RASopathy case-control comparison, unaffected-control count, or VCEP phenotypic point assignments. Therefore the governing point score cannot be evaluated; no PS4 strength is assigned. The PS4 rule's case-control note specifies RR/OR >5.0 with a confidence interval excluding 1.0, but the available studies do not provide the required matched case-control counts or estimates.
VCEP rule
Strength adjustment using point-based scoring for autosomal dominant cases with phenotypic specifications: full points awarded with RASopathy phenotypes, reduced points applicable to cases with minimal phenotypic information (i.e. prenatal cases, cases with a clinical order of a RASopathy panel without clinical information, and cases with limited clinical information in other global tests (such as WES)). ... ≥5 points. ... ≥3 points. ... ≥1 points.
Evidence considered
- The VCEP PS4 instructions require point-based scoring for autosomal-dominant cases with RASopathy phenotypic specifications; its strength rules are ≥1 point for Supporting, ≥3 points for Moderate, and ≥5 points for Strong.
- PMID:14612909 reports BRAF D593G, corresponding to the queried D594G under the newer numbering convention, in 1 of 164 non-Hodgkin lymphoma cases; the mutation was somatic and absent from corresponding normal tissue. This is not a RASopathy case-control dataset.
- PMID:14688025 reports D593G in one sigmoid-colon adenoma and BRAF mutations in 15 of 130 primary colorectal tumors; paired normal blood was used for somatic assessment. This is not a RASopathy case-control dataset.
- PMID:23352452 studies engineered D594G-B-Raf in cancer-cell assays and does not provide affected/unaffected RASopathy prevalence data.
- PMID:26498038 reports D594G in 8 cancer tumors, including one colorectal specimen with KRAS p.A59E; it is a somatic cancer cohort without unaffected controls or RASopathy phenotype scoring.
- The PS4 case-control requirement was not numerically evaluable: no matched case and control counts, RR/OR estimate, or confidence interval were reported in the reviewed variant-specific material, so no OR or 95% CI could be computed.
Still missing
- VCEP phenotypic point assignments for informative autosomal-dominant RASopathy cases are unavailable.
- No matched RASopathy case-control counts or RR/OR and confidence interval are available.
Sources