Starting
Initialising…
0%
MLH3
Final classification
VUS
MLH3 c.20T>A · p.Val7Asp
MLH3

NM_001040108.2:c.20T>A (p.Val7Asp) is a missense variant in exon 2 of MLH3, a DNA mismatch repair gene associated with autosomal dominant Lynch syndrome and autosomal recessive polyposis predisposition.

Gene
MLH3
Transcript
NM_001040108.2
HGVS · transcript:coding
NM_001040108.2:c.20T>A
Consequence
N/A
GRCh38
chr14:75049636 A>T
GRCh37
chr14:75516339 A>T
Basis gene-specific framework lacked a usable explicit final combination framework, so generic ACMG/AMP 2015 final-combination rules were applied as fallback; applied criteria: PM2 supporting; combination = 1 supporting, which maps to VUS.
gene-specific framework lacked a usable explicit final combination framework, so generic ACMG/AMP 2015 final-combination rules were applied as fallback; applied criteria: PM2 supporting; combination = 1 supporting, which maps to VUS.
Classification rationale
PM2 VUS
MLH3 c.20T>A

NM_001040108.2:c.20T>A (p.Val7Asp) is a missense variant in exon 2 of MLH3, a DNA mismatch repair gene associated with autosomal dominant Lynch syndrome and autosomal recessive polyposis predisposition. This variant is absent from gnomAD v2.1 and v4.1 population databases, supporting PM2 at a supporting strength level.1 Multiple computational predictors do not support a deleterious effect: REVEL score is 0.384 (intermediate), BayesDel is −0.281 (benign-leaning), and SpliceAI predicts no splice impact (max delta 0.00). PP3 is not met.2 The variant has been reported once in ClinVar as Uncertain significance by a single clinical laboratory (Ambry Genetics; Variation ID 1785889); no pathogenic or benign consensus exists.3 No variant-specific functional studies, case-control data, cosegregation evidence, or de novo observations were identified for this variant in the available evidence sources. The PVS1 criterion is not applicable as this is a missense change (p.Val7Asp) that does not meet the ClinGen SVI PVS1 null-variant criteria (PMC6185798).4 The variant has been observed once in a somatic cancer context (COSMIC COSV53136280), which is not directly informative for germline pathogenicity classification.

PM2 VUS
Gene diagram · NM_001040108.2 · variants mapped to exon structure
MLH3 NM_001040108.2
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
      Population frequency
      Absent from gnomAD v4.1.
      Absent from gnomAD v2.1.
      This variant is absent from gnomAD-Canada.
      ClinVar screenshot
      ClinVar
      This variant has been reported in ClinVar as Uncertain significance (1 clinical laboratory). (ClinVarID = 1785889)
      SpliceAI screenshot
      In silico
      SpliceAI predicts no significant splice impact for this variant (max delta score = 0.00). REVEL score = 0.384. BayesDel score = -0.280993.
      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. MLH3, a DNA mismatch repair protein, is infrequently altered in cancer.
      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 previously been reported in somatic cancers (COSMIC; COSV53136280, n = 1 times).
      Hotspots
      This variant does not lie in a statistically significant hotspot.
      Sources & reference links
      7Sources
      ClinVar
      gnomAD v2.1
      gnomAD v4.1
      SpliceAI
      OncoKB
      COSMIC
      Cancer hotspots