16-23637948-G-C
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate
The NM_024675.4(PALB2):c.113C>G(p.Ala38Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000548 in 1,461,030 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A38V) has been classified as Uncertain significance.
Frequency
Consequence
NM_024675.4 missense
Scores
Clinical Significance
Conservation
Publications
- hereditary breast carcinomaInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen, Ambry Genetics
- Fanconi anemia complementation group NInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
- pancreatic cancer, susceptibility to, 3Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
- familial ovarian cancerInheritance: AD Classification: MODERATE Submitted by: ClinGen
- Fanconi anemiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hereditary nonpolyposis colon cancerInheritance: AD Classification: LIMITED Submitted by: ClinGen
Genome browser will be placed here
ACMG classification
Our verdict: Likely_benign. The variant received -2 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_024675.4. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| PALB2 | NM_024675.4 | MANE Select | c.113C>G | p.Ala38Gly | missense | Exon 3 of 13 | NP_078951.2 | ||
| PALB2 | NM_001407296.1 | c.53C>G | p.Ala18Gly | missense | Exon 2 of 12 | NP_001394225.1 | |||
| PALB2 | NM_001407297.1 | c.113C>G | p.Ala38Gly | missense | Exon 3 of 12 | NP_001394226.1 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| PALB2 | ENST00000261584.9 | TSL:1 MANE Select | c.113C>G | p.Ala38Gly | missense | Exon 3 of 13 | ENSP00000261584.4 | ||
| PALB2 | ENST00000568219.5 | TSL:1 | c.-773C>G | 5_prime_UTR | Exon 3 of 13 | ENSP00000454703.2 | |||
| PALB2 | ENST00000561514.3 | TSL:5 | c.119C>G | p.Ala40Gly | missense | Exon 3 of 13 | ENSP00000460666.3 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.0000278 AC: 7AN: 251464 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.00000548 AC: 8AN: 1461030Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2AN XY: 726910 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:3
The p.A38G variant (also known as c.113C>G), located in coding exon 3 of the PALB2 gene, results from a C to G substitution at nucleotide position 113. The alanine at codon 38 is replaced by glycine, an amino acid with similar properties. This alteration was seen in two Chinese patients with early-onset breast cancer (Wong ESY et al. NPJ Genom. Med. 2016 Jan;1:15003). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.
not specified Uncertain:1
Variant summary: PALB2 c.113C>G (p.Ala38Gly) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 2.8e-05 in 251464 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.113C>G has been reported in the literature in individuals affected with Breast Cancer, some with a family history of other cancers, including those related to Hereditary Breast And Ovarian Cancer Syndrome (e.g. Wong_2016, Xie_2018, Kwong_2020). These reports do not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. At least one publication reports experimental evidence evaluating an impact on protein function in a mouse embryonic stem cell-based assay of homologous recombination-mediated repair (Ng_2022). These results showed no damaging effect of this variant versus the WT protein. The following publications have been ascertained in the context of this evaluation (PMID: 32068069, 33811135, 29263802, 28580595). ClinVar contains an entry for this variant (Variation ID: 318561). Based on the evidence outlined above, the variant was classified as uncertain significance.
Fanconi anemia complementation group N Uncertain:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease.
Familial cancer of breast Uncertain:1
This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 38 of the PALB2 protein (p.Ala38Gly). This variant is present in population databases (rs371875379, gnomAD 0.03%). This missense change has been observed in individual(s) with breast cancer (PMID: 28580595, 29263802). ClinVar contains an entry for this variant (Variation ID: 318561). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change does not substantially affect PALB2 function (PMID: 33811135). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at