NM_020975.6:c.1996A>C
Variant summary
Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PM5PP3_Moderate
The NM_020975.6(RET):c.1996A>C(p.Lys666Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,828 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. K666delinsNS) has been classified as Likely pathogenic.
Frequency
Consequence
NM_020975.6 missense
Scores
Clinical Significance
Conservation
Publications
- familial medullary thyroid carcinomaInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, G2P
- multiple endocrine neoplasia type 2AInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen, G2P
- multiple endocrine neoplasia type 2BInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae), ClinGen
- pheochromocytomaInheritance: AD Classification: DEFINITIVE Submitted by: G2P
- Hirschsprung disease, susceptibility to, 1Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- Haddad syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Hirschsprung diseaseInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- renal agenesis, unilateralInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- bilateral renal agenesisInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- renal agenesisInheritance: AR Classification: LIMITED Submitted by: G2P
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 6 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| RET | NM_020975.6 | c.1996A>C | p.Lys666Gln | missense_variant | Exon 11 of 20 | ENST00000355710.8 | NP_066124.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| RET | ENST00000355710.8 | c.1996A>C | p.Lys666Gln | missense_variant | Exon 11 of 20 | 5 | NM_020975.6 | ENSP00000347942.3 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.00000797 AC: 2AN: 250846 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.00000205 AC: 3AN: 1460828Hom.: 0 Cov.: 33 AF XY: 0.00000413 AC XY: 3AN XY: 726732 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Multiple endocrine neoplasia, type 2 Uncertain:1
This variant disrupts the p.Lys666 amino acid residue in RET. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 15858153, 20103606, 21690267, 26269449, 27673361). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. This sequence change replaces lysine, which is basic and polar, with glutamine, which is neutral and polar, at codon 666 of the RET protein (p.Lys666Gln). This variant is present in population databases (rs143795581, gnomAD 0.006%). This missense change has been observed in individual(s) with medullary thyroid cancer (PMID: 31510104). ClinVar contains an entry for this variant (Variation ID: 1045072). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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.K666Q variant (also known as c.1996A>C), located in coding exon 11 of the RET gene, results from an A to C substitution at nucleotide position 1996. The lysine at codon 666 is replaced by glutamine, an amino acid with similar properties. In one study, this alteration was detected in an Italian patient with medullary thyroid cancer (MTC) (Elisei R et al. Genes (Basel), 2019 09;10:). Similar alterations affecting this same amino acid, p.K666N and p.K666E, have been reported in multiple MTC patients and families (Xu JY et al. Thyroid. 2016 Oct, epub; Currás-Freixes M et al. J. Med. Genet., 2015 Oct;52:647-56; Ahmed SA et al. J Mol Diagn 2005;7:283-8). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for p.K666Q alteration is inconclusive. 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