14-95115683-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.1891A>G(p.Ile631Val) 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I631F) has been classified 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: 7.81

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 where missense usually causes diseases, DICER1

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DICER1	NM_177438.3	c.1891A>G	p.Ile631Val	missense_variant	11/27	ENST00000343455.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DICER1	ENST00000343455.8	c.1891A>G	p.Ile631Val	missense_variant	11/27	1	NM_177438.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

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

Invitae

Oct 23, 2018

This sequence change replaces isoleucine with valine at codon 631 of the DICER1 protein (p.Ile631Val). The isoleucine residue is highly conserved and there is a small physicochemical difference between isoleucine and valine. 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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with DICER1-related disease. This variant is not present in population databases (ExAC no frequency). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 07, 2020

The p.I631V variant (also known as c.1891A>G), located in coding exon 10 of the DICER1 gene, results from an A to G substitution at nucleotide position 1891. The isoleucine at codon 631 is replaced by valine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. 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: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Benign	-0.0067	T
BayesDel_noAF	Benign	-0.25
Cadd	Uncertain	26
Dann	Uncertain	1.0
DEOGEN2	Benign	0.30	T;T;T;T;.
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Benign	0.019	T
MetaRNN	Uncertain	0.49	T;T;T;T;T
MetaSVM	Benign	-0.84	T
MutationAssessor	Benign	0.93	L;L;L;L;L
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	-0.73	N;N;N;N;N
REVEL	Benign	0.26
Sift	Benign	0.12	T;T;T;T;T
Sift4G	Benign	0.13	T;T;T;T;T
Polyphen		0.99	D;D;D;D;.
Vest4		0.60
MutPred		0.52		Loss of catalytic residue at I631 (P = 0.0918);Loss of catalytic residue at I631 (P = 0.0918);Loss of catalytic residue at I631 (P = 0.0918);Loss of catalytic residue at I631 (P = 0.0918);Loss of catalytic residue at I631 (P = 0.0918);
MVP		0.59
MPC		0.99
ClinPred		0.81	D
GERP RS		5.1
Varity_R		0.26
gMVP		0.53

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: rs878855245; hg19: chr14-95582020;