rs542398644

chr14-95112225-C-Achr14-95112225-C-Gchr14-95112225-C-T

Variant summary

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

The NM_177438.3(DICER1):c.2063G>T(p.Arg688Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,750 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R688Q) 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: 7.88

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.2063G>T	p.Arg688Leu	missense_variant	13/27	ENST00000343455.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DICER1	ENST00000343455.8	c.2063G>T	p.Arg688Leu	missense_variant	13/27	1	NM_177438.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251378 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135864

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461750 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727172

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.: 32

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

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

Nov 13, 2022

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt DICER1 protein function. ClinVar contains an entry for this variant (Variation ID: 963942). 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 arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 688 of the DICER1 protein (p.Arg688Leu). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 16, 2021

The p.R688L variant (also known as c.2063G>T), located in coding exon 12 of the DICER1 gene, results from a G to T substitution at nucleotide position 2063. The arginine at codon 688 is replaced by leucine, an amino acid with dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious 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	Uncertain	0.42
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.15
Cadd	Pathogenic	27
Dann	Uncertain	1.0
DEOGEN2	Benign	0.41	T;T;T;T;.
Eigen	Uncertain	0.27
Eigen_PC	Uncertain	0.26
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Benign	0.061	D
MetaRNN	Uncertain	0.73	D;D;D;D;D
MetaSVM	Benign	-0.86	T
MutationAssessor	Benign	0.94	L;L;L;L;L
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.64	T
PROVEAN	Benign	-1.3	N;N;N;N;N
REVEL	Uncertain	0.35
Sift	Benign	0.37	T;T;T;T;T
Sift4G	Benign	0.40	T;T;T;T;T
Polyphen		0.83	P;P;P;P;.
Vest4		0.87
MutPred		0.56		Gain of catalytic residue at E691 (P = 0.0864);Gain of catalytic residue at E691 (P = 0.0864);Gain of catalytic residue at E691 (P = 0.0864);Gain of catalytic residue at E691 (P = 0.0864);Gain of catalytic residue at E691 (P = 0.0864);
MVP		0.91
MPC		1.3
ClinPred		0.93	D
GERP RS		5.4
Varity_R		0.34
gMVP		0.67

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: rs542398644; hg19: chr14-95578562;