Starting
Initialising…
0%
PALB2
Final classification
VUS
PALB2 c.3049G>A · p.Ala1017Thr
PALB2

NM_024675.3:c.3049G>A (p.Ala1017Thr) is a missense variant in PALB2, a gene for which loss of function is an established mechanism of PALB2-related cancer predisposition (autosomal dominant) and Fanconi anemia complementation group N (autosomal recessive).

Gene
PALB2
Transcript
NM_024675.3
HGVS · transcript:coding
NM_024675.3:c.3049G>A
Consequence
N/A
GRCh38
chr16:23621426 C>T
GRCh37
chr16:23632747 C>T
Basis Richards et.al., 2015 - Combining rules v1.2.0 criteria-combination framework was evaluated deterministically with applied criteria: BP1 supporting benign; no rule matched the adjudicated criteria.
Richards et.al., 2015 - Combining rules v1.2.0 criteria-combination framework was evaluated deterministically with applied criteria: BP1 supporting benign; no rule matched the adjudicated criteria.
Classification rationale
BP1 VUS
PALB2 c.3049G>A

NM_024675.3:c.3049G>A (p.Ala1017Thr) is a missense variant in PALB2, a gene for which loss of function is an established mechanism of PALB2-related cancer predisposition (autosomal dominant) and Fanconi anemia complementation group N (autosomal recessive).1 This variant has been classified as a Variant of Uncertain Significance by the ClinGen Hereditary Breast, Ovarian and Pancreatic Cancer Variant Curation Expert Panel (ClinVar Variation ID: 830187) and by seven clinical laboratories.2 In gnomAD v4.1, this variant is present at an overall allele frequency of 0.000081% (13/1,614,106 alleles; grpmax FAF=0.0075%), with the highest frequency in the South Asian population (0.0132%; 12/91,078 alleles). The gnomAD v2.1 frequency is 0.00040% (1/251,448 alleles).3 SpliceAI predicts no splicing impact (max delta score = 0.00). REVEL score is 0.202 and BayesDel score is -0.306, both in ranges consistent with a benign computational prediction, though in silico predictors are not used for missense variants under the PALB2 VCEP framework.4 Under the PALB2 VCEP v1.2.0 framework, BP1 (Supporting) is met because all PALB2 missense variants are assigned BP1 at Supporting strength, given the very low rate of functional missense variants in PALB2. No other criteria are met under this VCEP framework.5 The PM2 (Supporting) criterion is not met because the variant's gnomAD v4.1 frequency (0.00081%) exceeds the VCEP threshold of ≤0.000333%. Population frequency criteria BA1 (>0.1%) and BS1 (>0.01%) are also not met, as the grpmax FAF (0.0075%) falls below both thresholds.6 PS4 is not met; although this variant has been observed in 3 cancer cases in a case-control study (Momozawa et al. 2018), no formal odds ratio or statistical significance test meeting the VCEP threshold (OR≥3, p≤0.05) has been computed for this individual variant.7 Many ACMG/AMP criteria are not applicable under the PALB2 VCEP for missense variants, including PVS1 (not a null variant), PS1/PP3/BP4 (missense excluded), PM1 (missense mechanism not confirmed), PM5 (truncation/splice only), PP2 (missense mechanism not confirmed), and PS3/BS3 (not used in this VCEP).8 Several criteria (PP1, BS2, BS4) remain not assessed due to absence of published co-segregation, healthy adult proband, or non-segregation data for this specific variant.9 With only BP1_Supporting met and no pathogenic criteria met, this variant does not satisfy the criteria for Likely Benign (requires ≥2 benign supporting or 1 strong benign + ≥1 supporting benign). The variant remains classified as a Variant of Uncertain Significance (VUS) under the PALB2 VCEP v1.2.0 framework.10

BP1 VUS
Gene diagram · NM_024675.3 · variants mapped to exon structure
PALB2 NM_024675.3
Fetching transcript structure from UCSC…
Applied criteria · 1 met · select any tile
Met
Not met
Not assessed
N/A
Strength very strong supporting
Pathogenic evidence
PVS
PS
PM
PP
Benign evidence
BA
BS
BP
Rationale
Select a criterion.
Sources
Evidence used
    Gaps remaining
      Rule
      Research & evidence
      Population frequency
      gnomAD v4.1 screenshot
      gnomAD v4.1
      gnomAD v2.1 screenshot
      gnomAD v2.1
      v4.1
      This variant is present in gnomAD v4.1 (AF= 8.05399e-06; MAF= 0.00081%, 13/1614106 alleles, homozygotes = 0) and has highest observed frequency in the South Asian population (AF= 0.000131755; MAF= 0.01318%, 12/91078 alleles, homozygotes = 0); grpmax FAF= 7.506e-05.
      v2.1
      This variant is present in gnomAD v2.1 (AF= 3.97697e-06; MAF= 0.00040%, 1/251448 alleles, homozygotes = 0) and has highest observed frequency in the South Asian population (AF= 3.26627e-05; MAF= 0.00327%, 1/30616 alleles, homozygotes = 0).
      🇨🇦 CA
      This variant is absent from gnomAD-Canada.
      Allele frequency by ancestry
      three datasets · side by side
      gnomAD v4.1
      0.00081% · 13 / 1,614,106
      0 hom · FAF 0.0075%
      South Asian
      12 / 91,078
      0.013%
      Remaining individuals
      1 / 62,508
      0.0016%
      + 8 not observed (Admixed American, European (Finnish), Amish, East Asian, Middle Eastern, Ashkenazi Jewish, African/African American, European (non-Finnish))
      gnomAD v2.1
      0.0004% · 1 / 251,448
      0 hom
      South Asian
      1 / 30,616
      0.0033%
      + 7 not observed (African/African American, Admixed American, Ashkenazi Jewish, East Asian, European (Finnish), European (non-Finnish), Remaining individuals)
      gnomAD Canada 🇨🇦
      Absent · 0 / ?
      0 hom
      Not observed in any ancestry group.
      ClinVar screenshot
      ClinVar
      This variant has been reported in ClinVar as Uncertain significance (7 clinical laboratories) and as Uncertain Significance by ClinGen Hereditary Breast, Ovarian and Pancreatic Cancer Variant Curation Expert Panel, ClinGen (expert panel). (ClinVarID = 830187)
      SpliceAI screenshot
      In silico
      SpliceAI predicts no significant splice impact for this variant (max delta score = 0.00). REVEL score = 0.202. BayesDel score = -0.305671.
      Functional / OncoKB screenshot
      Functional Unknown Oncogenic Effect
      OncoKB did not identify variant-specific reviewed functional evidence for this variant; gene-level curated context is available for reviewer follow-up. PALB2, a scaffolding protein involved in DNA repair, is altered in various cancers.
      OncoKB ↗
      COSMIC screenshot
      COSMIC
      Cancer hotspots screenshot
      Cancer hotspots
      Somatic evidence Not in COSMIC / hotspots
      COSMIC
      This variant does not lie in a statistically significant hotspot. This variant has not previously been reported in somatic cancers (COSMIC).
      Hotspots
      This variant does not lie in a statistically significant hotspot.
      Sources & reference links
      8Sources
      CSpec VCEP
      ClinVar
      gnomAD v2.1
      gnomAD v4.1
      SpliceAI
      OncoKB
      COSMIC
      Cancer hotspots
      Triaged references · 9 PMIDs not cited in assessment
      23977390 ↗ Prevalence of PALB2 mutations in breast cancer patients in multi-ethnic Asian population in Malaysia and Singapore. CLINVAR
      25741868 ↗ Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. CLINVAR
      26467025 ↗ A Standardized DNA Variant Scoring System for Pathogenicity Assessments in Mendelian Disorders. CLINVAR
      31586400 ↗ A global functional analysis of missense mutations reveals two major hotspots in the PALB2 tumor suppressor. CLINVAR
      34242744 ↗ Customizing local and systemic therapies for women with early breast cancer: the St. Gallen International Consensus Guidelines for treatment of early breast cancer 2021. CLINVAR
      15604628 ↗ Genetic cancer risk assessment and counseling: recommendations of the national society of genetic counselors. CLINVAR
      17508274 ↗ Risk assessment and genetic counseling for hereditary breast and ovarian cancer: recommendations of the National Society of Genetic Counselors. CLINVAR
      18163131 ↗ The emerging landscape of breast cancer susceptibility. CLINVAR
      28492532 ↗ Sherloc: a comprehensive refinement of the ACMG-AMP variant classification criteria. CLINVAR