Reasoning
The ClinGen HBOP ATM VCEP v1.5 PM3/BP2 specification requires affected Ataxia-Telangiectasia proband observations and weighs phase with a pathogenic or likely pathogenic ATM variant: confirmed trans receives 4.0 points for a confident phenotype or 2.0 for a consistent phenotype, phase unknown receives 2.0 or 1.0, and homozygosity receives 2.0 or 1.0, with PM3 Supporting at 1.0 point, Moderate at 2.0, Strong at 4.0, and Very Strong at 8.0. The variant is sufficiently rare for consideration (gnomAD v4.1 grpmax FAF 6.8e-07), but the available case evidence does not document an affected proband carrying NM_000051.4:c.8292_8293del with a second ATM pathogenic/likely pathogenic variant, confirmed phase, or qualifying homozygosity. The governing file ATM_PM3_BP2_1.5.pdf was searched under c.8292_8293del, p.Ser2764ArgfsTer4, and p.S2764Rfs*4, with no variant-specific table entry found; the available literature extracts likewise report no exact-variant observation. Therefore no PM3 points can be assigned from the supplied evidence.
Rule
ClinGen HBOP ATM VCEP v1.5 PM3/BP2 points table: PM3 Supporting = 1.0 point, Moderate = 2.0 points, Strong = 4.0 points, Very Strong = 8.0 points; assign points by affected-proband phenotype and phase.
Evidence considered
- ClinGen HBOP ATM VCEP v1.5 assigns 4.0 PM3 points for a confident-phenotype affected proband with confirmed trans phase, 2.0 points for phase unknown, 2.0 points for a consistent-phenotype confirmed-trans observation, and converts 1.0, 2.0, 4.0, and 8.0 points to Supporting, Moderate, Strong, and Very Strong PM3, respectively.
- gnomAD v4.1 reports this variant at grpmax FAF 6.8e-07, below the VCEP's 0.01% general-frequency ceiling for PM3 consideration.
- Searches of ATM_PM3_BP2_1.5.pdf for c.8292_8293del, p.Ser2764ArgfsTer4, and p.S2764Rfs*4 found no variant-specific table entry.
- The extracted findings for PMID:23807571, PMID:25614872, and PMID:31050087 state that the exact variant was not mentioned and provide no variant-specific phase or affected-proband data.
Still missing
- No affected Ataxia-Telangiectasia proband record with this variant and a second ATM pathogenic/likely pathogenic variant, including phase, is available.
- No qualifying homozygous affected individual or phenotype classification is documented.
- No variant-specific entry was found in ATM_PM3_BP2_1.5.pdf after searching c.8292_8293del, p.Ser2764ArgfsTer4, and p.S2764Rfs*4.
Sources