--- title: "RET C620S (c.1859G>C, rs77503355) | Dante Labs" description: "ClinVar classifies RET C620S as Pathogenic (criteria provided, multiple submitters, no conflicts). Where it sits in the genome, its predicted effect, and the Genome Test reports that look at it." url: "https://dantelabs.com/genes/ret/variants/c620s" --- 1. [Genes](https://dantelabs.com/genes) 2. [RET](https://dantelabs.com/genes/ret) 3. RET C620S Variant # RET C620S NM_020975.6(RET):c.1859G>C (p.Cys620Ser) Also known as - p.Cys620Ser - p.C620S - rs77503355 * ClinVar classification Pathogenic * Review status 2 stars out of 4 criteria provided, multiple submitters, no conflicts * Last evaluated 27 March 2024 Data current to ClinVar release 2026-10-12 · Dante Labs data release 2026.10.16-c6eea6bf Facts last changed 16 October 2026 ## Summary C620S is a missense variant in RET: it changes a single amino acid in the protein the gene encodes. ClinVar classifies it as pathogenic for Multiple Endocrine Neoplasia Type 2 (criteria provided, multiple submitters, no conflicts). ## ClinVar classifications | Condition | Classification | Review status | Submissions | Last evaluated | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | -------------- | --------------------------------------------------------------------- | ------------- | -------------- | | [Multiple Endocrine Neoplasia Type 2](https://dantelabs.com/conditions/thyroid-cancer-report) [ClinVar VCV000013943 (opens in a new tab)](https://www.ncbi.nlm.nih.gov/clinvar/variation/13943/) | Pathogenic | 2 stars out of 4 criteria provided, multiple submitters, no conflicts | 2 submissions | 27 March 2024 | Classifications as ClinVar records them in release 2026-10-12. ClinVar updates them as evidence is reviewed. ## Where it lies in RET C620S lies in exon 10 of the 20 in RET's MANE Select transcript, NM_020975.6. [RET variants in exon 10 →](https://dantelabs.com/genes/ret/variants?exon=10) [RET's gene diagram →](https://dantelabs.com/genes/ret#gene-structure) ## Molecular details | Gene | [RET](https://dantelabs.com/genes/ret) | | --------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- | | Transcript | NM_020975.6 MANE Select | | Coding DNA change (HGVS c.) | c.1859G>C | | Protein change (HGVS p.) | p.Cys620Ser p.C620S | | Predicted consequence | Missense [missense_variant (opens in a new tab)](https://purl.obolibrary.org/obo/SO_0001583) | | Predicted impact | Moderate | | Position (GRCh38) | chr10:43113655 G>C | | Position (GRCh37) | chr10:43609103 G>C | | dbSNP ID | [rs77503355 (opens in a new tab)](https://www.ncbi.nlm.nih.gov/snp/rs77503355) | | ClinVar Variation ID | [VCV000013943 (opens in a new tab)](https://www.ncbi.nlm.nih.gov/clinvar/variation/13943/) | | ClinVar Allele ID | 28982 | | ClinGen Allele Registry ID | [CA008085 (opens in a new tab)](https://reg.clinicalgenome.org/redmine/projects/registry/genboree_registry/by_canonicalid?canonicalid=CA008085) | | ClinVar name | NM_020975.6(RET):c.1859G>C (p.Cys620Ser) | ## RET C620S in other databases - [ClinVar VCV000013943 (opens in a new tab)](https://www.ncbi.nlm.nih.gov/clinvar/variation/13943/) - [dbSNP rs77503355 (opens in a new tab)](https://www.ncbi.nlm.nih.gov/snp/rs77503355) - [ClinGen Allele Registry CA008085 (opens in a new tab)](https://reg.clinicalgenome.org/redmine/projects/registry/genboree_registry/by_canonicalid?canonicalid=CA008085) - [gnomAD 10-43113655-G-C (opens in a new tab)](https://gnomad.broadinstitute.org/variant/10-43113655-G-C?dataset=gnomad_r4) - [Ensembl rs77503355 (opens in a new tab)](https://www.ensembl.org/Homo_sapiens/Variation/Explore?v=rs77503355) ## Reports that look at this variant (2) These Genome Test condition reports include C620S among the variants they look at. | Report | Conditions | Inheritance | | --------------------------------------------------------------------------------------------- | ----------------------------------- | ------------------ | | [Malignant Endocrine Neoplasm](https://dantelabs.com/conditions/malignant-endocrine-neoplasm) | Malignant Endocrine Neoplasm | | | | Multiple Endocrine Neoplasia | Autosomal dominant | | [Thyroid Cancer](https://dantelabs.com/conditions/thyroid-cancer-report) | Thyroid Tumor | | | | Thyroid Cancer | | | | Thyroid Gland Carcinoma | | | | Multiple Endocrine Neoplasia Type 2 | Autosomal dominant | | | Thyroid Gland Disorder | | ## Other variants in RET - [c.1852T>A Pathogenic 2 stars out of 4](https://dantelabs.com/genes/ret/variants/c-1852t-a) - [c.1858T>A Pathogenic/likely pathogenic 2 stars out of 4](https://dantelabs.com/genes/ret/variants/c-1858t-a) - [c.1947G>A Pathogenic/likely pathogenic 2 stars out of 4](https://dantelabs.com/genes/ret/variants/c-1947g-a) - [c.1998G>C Pathogenic/likely pathogenic 2 stars out of 4](https://dantelabs.com/genes/ret/variants/c-1998g-c) - [c.2370G>T Pathogenic 2 stars out of 4](https://dantelabs.com/genes/ret/variants/c-2370g-t) - [c.2410G>C Pathogenic/likely pathogenic 2 stars out of 4](https://dantelabs.com/genes/ret/variants/c-2410g-c) - [C609R Pathogenic 2 stars out of 4](https://dantelabs.com/genes/ret/variants/c609r) - [C609Y Pathogenic 2 stars out of 4](https://dantelabs.com/genes/ret/variants/c609y) - [C611F Pathogenic 2 stars out of 4](https://dantelabs.com/genes/ret/variants/c611f) - [C611Y Pathogenic 2 stars out of 4](https://dantelabs.com/genes/ret/variants/c611y) [All RET variants](https://dantelabs.com/genes/ret/variants) ## Limitations This page describes publicly available information about a genetic variant. It is not a diagnosis, and it says nothing about whether you or anyone else carries this variant. Classifications come from ClinVar and change as new evidence is reviewed. A classification here may differ from the one in ClinVar today, or from the one a laboratory reports. Whole genome sequencing with short reads can miss or miscall some variants, particularly in repeated or highly similar stretches of DNA and in large insertions, deletions or rearrangements. If you have questions about a variant in your own results or in your family, talk to a genetic counsellor or your doctor. ## Sources & credits - Classifications from ClinVar (release 2026-10-12), National Center for Biotechnology Information. - Condition terms from the Mondo Disease Ontology (release 2026-10-06), used under CC BY 4.0. - Gene symbols and names from the HUGO Gene Nomenclature Committee (release 2026-10-16). - Allele identifiers from the ClinGen Allele Registry (release 2026-10-16-c4908f54). - Reference SNP identifiers from dbSNP (release b157), National Center for Biotechnology Information. - Gene–disease links from the Gene Curation Coalition, GenCC (release 2026-10-16). - Difficult regions from the Genome in a Bottle Consortium (release v3.6). - Transcripts from MANE (release v1.5), NCBI and EMBL-EBI. - Predicted consequences from mehari (release 0.11.0), with transcript models from cdot. - Built from Dante Labs data release 2026.10.16-c6eea6bf of 16 October 2026. ## Cite this page APA > Dante Labs. (16 October 2026). RET C620S (c.1859G>C, rs77503355) (Version 2026.10.16-c6eea6bf). Retrieved 17 October 2026, from https\://dantelabs.com/genes/ret/variants/c620s Vancouver > Dante Labs. RET C620S (c.1859G>C, rs77503355) \[Internet]. Version 2026.10.16-c6eea6bf. 16 October 2026 \[cited 17 October 2026]. Available from: https\://dantelabs.com/genes/ret/variants/c620s Download citation [RIS](https://dantelabs.com/genes/ret/variants/c620s/cite.ris) [BibTeX](https://dantelabs.com/genes/ret/variants/c620s/cite.bib) [CSL-JSON](https://dantelabs.com/genes/ret/variants/c620s/cite.json) ## Read your whole genome From $449 Free shipping · Results in 6–8 weeks [Explore the Genome Test](https://dantelabs.com/whole-genome-sequencing)