14-95129488-G-T

Position:

• chr14-95129488-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_177438.3(DICER1):​c.718C>A​(p.Leu240Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,102 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: DICER1 NM_177438.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.44

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 2 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.34484273).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DICER1	NM_177438.3	c.718C>A	p.Leu240Met	missense_variant	6/27	ENST00000343455.8	NP_803187.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DICER1	ENST00000343455.8	c.718C>A	p.Leu240Met	missense_variant	6/27	1	NM_177438.3	ENSP00000343745	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152102 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152102 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74292

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

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

Oct 18, 2023

This sequence change replaces leucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 240 of the DICER1 protein (p.Leu240Met). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with DICER1-related conditions. 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. 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

Oct 26, 2023

The p.L240M variant (also known as c.718C>A), located in coding exon 5 of the DICER1 gene, results from a C to A substitution at nucleotide position 718. The leucine at codon 240 is replaced by methionine, 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	Uncertain	0.51
BayesDel_addAF	Benign	-0.016	T
BayesDel_noAF	Benign	-0.26
CADD	Benign	18
DANN	Uncertain	0.98
DEOGEN2	Benign	0.40	T;T;T;T;.
Eigen	Benign	0.041
Eigen_PC	Benign	-0.040
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Uncertain	0.90	.;.;D;.;D
M_CAP	Benign	0.041	D
MetaRNN	Benign	0.34	T;T;T;T;T
MetaSVM	Benign	-0.74	T
MutationAssessor	Uncertain	2.2	M;M;M;M;M
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.77	T
PROVEAN	Benign	-1.1	N;N;N;N;N
REVEL	Benign	0.17
Sift	Uncertain	0.0070	D;D;D;D;D
Sift4G	Uncertain	0.023	D;D;D;D;D
Polyphen		0.91	P;P;P;P;.
Vest4		0.52
MutPred		0.33		Loss of helix (P = 0.0376);Loss of helix (P = 0.0376);Loss of helix (P = 0.0376);Loss of helix (P = 0.0376);Loss of helix (P = 0.0376);
MVP		0.71
MPC		1.1
ClinPred		0.94	D
GERP RS		-2.9
Varity_R		0.46
gMVP		0.45

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: rs1060503615; hg19: chr14-95595825;