rs769399180
Variant summary
Our verdict is Likely benign. The variant received -5 ACMG points: 1P and 6B. PP2BP4_ModerateBS2
The NM_000222.3(KIT):c.954G>A(p.Met318Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000709 in 1,410,764 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M318V) has been classified as Likely benign.
Frequency
Consequence
NM_000222.3 missense
Scores
Clinical Significance
Conservation
Publications
- gastrointestinal stromal tumorInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, Ambry Genetics
- piebaldismInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp
- cutaneous mastocytosisInheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- mastocytosisInheritance: AD Classification: STRONG, MODERATE Submitted by: Genomics England PanelApp, Ambry Genetics
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ACMG classification
Our verdict: Likely_benign. The variant received -5 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| KIT | NM_000222.3 | c.954G>A | p.Met318Ile | missense_variant | Exon 6 of 21 | ENST00000288135.6 | NP_000213.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| KIT | ENST00000288135.6 | c.954G>A | p.Met318Ile | missense_variant | Exon 6 of 21 | 1 | NM_000222.3 | ENSP00000288135.6 |
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD2 exomes AF: 0.0000120 AC: 3AN: 250242 AF XY: 0.00000739 show subpopulations
GnomAD4 exome AF: 0.00000709 AC: 10AN: 1410764Hom.: 1 Cov.: 27 AF XY: 0.00000993 AC XY: 7AN XY: 705054 show subpopulations ⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
Age Distribution
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
Gastrointestinal stromal tumor Uncertain:2
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This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 318 of the KIT protein (p.Met318Ile). This variant is present in population databases (rs769399180, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with KIT-related conditions. ClinVar contains an entry for this variant (Variation ID: 237287). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The isoleucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -
Hereditary cancer-predisposing syndrome Uncertain:1
The p.M318I variant (also known as c.954G>A), located in coding exon 6 of the KIT gene, results from a G to A substitution at nucleotide position 954. The methionine at codon 318 is replaced by isoleucine, an amino acid with highly similar properties. This amino acid position is conserved. 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at