14-95096023-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_177438.3(DICER1):c.4897G>A(p.Val1633Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign 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. V1633L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: DICER1 NM_177438.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.13

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, DICER1
• BP4: Computational evidence support a benign effect (MetaRNN=0.07053444).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DICER1	NM_177438.3	c.4897G>A	p.Val1633Ile	missense_variant	23/27	ENST00000343455.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DICER1	ENST00000343455.8	c.4897G>A	p.Val1633Ile	missense_variant	23/27	1	NM_177438.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461892 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

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

Dec 09, 2020

In summary, this variant is a novel missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. 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 tolerated, but these predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a DICER1-related disease. This sequence change replaces valine with isoleucine at codon 1633 of the DICER1 protein (p.Val1633Ile). The valine residue is weakly conserved and there is a small physicochemical difference between valine and isoleucine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 29, 2022

The p.V1633I variant (also known as c.4897G>A), located in coding exon 22 of the DICER1 gene, results from a G to A substitution at nucleotide position 4897. The valine at codon 1633 is replaced by isoleucine, an amino acid with highly similar properties. This amino acid position is conserved. 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	0.071
BayesDel_addAF	Benign	-0.089	T
BayesDel_noAF	Benign	-0.37
Cadd	Benign	13
Dann	Benign	0.87
DEOGEN2	Benign	0.20	T;T;T;T;.;.
Eigen	Benign	-0.70
Eigen_PC	Benign	-0.62
FATHMM_MKL	Benign	0.45	N
M_CAP	Benign	0.027	D
MetaRNN	Benign	0.071	T;T;T;T;T;T
MetaSVM	Benign	-0.76	T
MutationAssessor	Benign	0.69	N;N;N;N;.;N
MutationTaster	Benign	1.0	N;N;N;N;N;N
PrimateAI	Benign	0.28	T
PROVEAN	Benign	-0.14	N;N;N;N;N;N
REVEL	Benign	0.059
Sift	Benign	0.44	T;T;T;T;T;T
Sift4G	Benign	0.24	T;T;T;T;T;T
Polyphen		0.0010	B;B;B;B;.;.
Vest4		0.12
MutPred		0.18		Gain of helix (P = 0.0854);Gain of helix (P = 0.0854);Gain of helix (P = 0.0854);Gain of helix (P = 0.0854);.;Gain of helix (P = 0.0854);
MVP		0.65
MPC		0.40
ClinPred		0.035	T
GERP RS		3.4
Varity_R		0.017
gMVP		0.23

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: rs1060503643; hg19: chr14-95562360;