rs377767428

Positions:

• chr10-43120120-G-A
• chr10-43120120-G-C
• chr10-43120120-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PM5 PP3

The NM_020975.6(RET):​c.2647G>A​(p.Ala883Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,696 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. A883F) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: RET NM_020975.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 6.89

Genes affected

RET (HGNC:9967): (ret proto-oncogene) This gene encodes a transmembrane receptor and member of the tyrosine protein kinase family of proteins. Binding of ligands such as GDNF (glial cell-line derived neurotrophic factor) and other related proteins to the encoded receptor stimulates receptor dimerization and activation of downstream signaling pathways that play a role in cell differentiation, growth, migration and survival. The encoded receptor is important in development of the nervous system, and the development of organs and tissues derived from the neural crest. This proto-oncogene can undergo oncogenic activation through both cytogenetic rearrangement and activating point mutations. Mutations in this gene are associated with Hirschsprung disease and central hypoventilation syndrome and have been identified in patients with renal agenesis. [provided by RefSeq, Sep 2017]

RET (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.771

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RET	NM_020975.6	c.2647G>A	p.Ala883Thr	missense_variant	15/20	ENST00000355710.8	NP_066124.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RET	ENST00000355710.8	c.2647G>A	p.Ala883Thr	missense_variant	15/20	5	NM_020975.6	ENSP00000347942.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461696 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 727142

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Multiple endocrine neoplasia, type 2 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Mar 09, 2023	This missense variant replaces alanine with threonine at codon 883 of the RET protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). A functional study has reported that this variant has low transforming activity based on focal formation, soft-agar growth and growth rate assays in ex vivo cells (PMID: 21810974). This variant has been reported in four individuals from three families affected with medullary thyroid cancer that include two unrelated heterozygous carriers (PMID: 28946813, 29515777, 31510104) and two siblings from a consanguineous family who are homozygous for this variant (PMID: 15531548, 31510104). At least three heterozygous carriers from this consanguineous family who are older than the affected siblings are asymptomatic for thyroid-related disease (PMID: 15531548). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 31, 2021	This sequence change replaces alanine with threonine at codon 883 of the RET protein (p.Ala883Thr). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and threonine. This variant is not present in population databases (ExAC no frequency). This missense change has been observed in individual(s) with medullary thyroid carcinoma (PMID: 15531548, 25440022, 28946813). ClinVar contains an entry for this variant (Variation ID: 24958). 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: "Possibly Damaging"; Align-GVGD: "Class C0"). Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on RET function (PMID: 21810974). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. This variant disrupts the p.Ala883 amino acid residue in RET. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9294615, 10679286, 21186952, 25244518, 28323957). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 17, 2024

The p.A883T variant (also known as c.2647G>A), located in coding exon 15 of the RET gene, results from a G to A substitution at nucleotide position 2647. The alanine at codon 883 is replaced by threonine, an amino acid with similar properties. This variant has been reported in the homozyous state in two brothers with medullary thyroid cancer (MTC) diagnosed in their fifties; however, four relatives who were heterozygous for the variant did not have MTC (Elisei R et al. J. Clin. Endocrinol. Metab. 2004 Nov;89:5823-7). Studies of familial MTC, as well as apparently sporadic MTC cases, have identified this variant (Romei C et al. Eur. J. Endocrinol. 2010 Aug;163:301-8; Romei C et al. Clin. Endocrinol. (Oxf). 2015 Jun;82:892-9; Lebeault M et al. Thyroid. 2017 12;27:1511-1522; Romei C et al. Oncotarget. 2018 Feb;9:9875-9884). In vitro assays analyzing the transforming activity of RET variants, found that this variant had an intermediate number of focus formation units, therefore described as having low or non-transforming potential (Cosci B et al. Endocr. Relat. Cancer. 2011 Oct;18:603-12). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.80	D;.
Eigen	Uncertain	0.29
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.77	D;D
MetaSVM	Benign	-0.78	T
MutationAssessor	Benign	-0.80	N;N
PrimateAI	Pathogenic	0.80	T
PROVEAN	Uncertain	-3.6	D;D
REVEL	Pathogenic	0.77
Sift	Benign	0.10	T;D
Sift4G	Benign	0.20	T;T
Polyphen		1.0	D;D
Vest4		0.49
MutPred		0.86		Loss of sheet (P = 0.1158);Loss of sheet (P = 0.1158);
MVP		0.95
MPC		0.54
ClinPred		0.99	D
GERP RS		5.5
Varity_R		0.84
gMVP		0.84

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs377767428; hg19: chr10-43615568;