rs878855243

Positions:

• chr14-95117651-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_177438.3(DICER1):​c.1480A>G​(p.Met494Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: DICER1 NM_177438.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.92

Genes affected

DICER1 (HGNC:17098): (dicer 1, ribonuclease III) This gene encodes a protein possessing an RNA helicase motif containing a DEXH box in its amino terminus and an RNA motif in the carboxy terminus. The encoded protein functions as a ribonuclease and is required by the RNA interference and small temporal RNA (stRNA) pathways to produce the active small RNA component that represses gene expression. This protein also acts as a strong antiviral agent with activity against RNA viruses, including the Zika and SARS-CoV-2 viruses. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2021]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), DICER1. . Gene score misZ 4.2261 (greater than the threshold 3.09). Trascript score misZ 6.1353 (greater than threshold 3.09). GenCC has associacion of gene with goiter, multinodular 1, with or without Sertoli-Leydig cell tumors, global developmental delay - lung cysts - overgrowth - Wilms tumor syndrome, DICER1-related tumor predisposition, DICER1 syndrome, pleuropulmonary blastoma.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DICER1	NM_177438.3	c.1480A>G	p.Met494Val	missense_variant	9/27	ENST00000343455.8	NP_803187.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DICER1	ENST00000343455.8	c.1480A>G	p.Met494Val	missense_variant	9/27	1	NM_177438.3	ENSP00000343745	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

DICER1-related tumor predisposition Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 12, 2022

ClinVar contains an entry for this variant (Variation ID: 242040). This variant has not been reported in the literature in individuals affected with DICER1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 494 of the DICER1 protein (p.Met494Val). 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. 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: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 07, 2023

The p.M494V variant (also known as c.1480A>G), located in coding exon 8 of the DICER1 gene, results from an A to G substitution at nucleotide position 1480. The methionine at codon 494 is replaced by valine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.16
BayesDel_addAF	Uncertain	0.094	D
BayesDel_noAF	Benign	-0.10
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.31	T;T;T;T;.
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.93	.;.;D;.;D
M_CAP	Benign	0.055	D
MetaRNN	Uncertain	0.52	D;D;D;D;D
MetaSVM	Benign	-0.63	T
MutationAssessor	Benign	-0.11	N;N;N;N;N
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Benign	-0.31	N;N;N;N;N
REVEL	Uncertain	0.35
Sift	Benign	0.27	T;T;T;T;T
Sift4G	Benign	1.0	T;T;T;T;T
Polyphen		0.98	D;D;D;D;.
Vest4		0.68
MutPred		0.38		Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);
MVP		0.77
MPC		1.3
ClinPred		0.91	D
GERP RS		5.2
Varity_R		0.27
gMVP		0.63

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs878855243; hg19: chr14-95583988;