rs775370673

chr14-95126746-T-Achr14-95126746-T-C

Variant summary

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

The NM_177438.3(DICER1):c.737A>T(p.Tyr246Phe) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. 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. Y246C) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 31)
• Consequence: DICER1 NM_177438.3 missense, splice_region
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.41

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 where missense usually causes diseases, DICER1
• BP4: Computational evidence support a benign effect (MetaRNN=0.3175423).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DICER1	NM_177438.3	c.737A>T	p.Tyr246Phe	missense_variant, splice_region_variant	7/27	ENST00000343455.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DICER1	ENST00000343455.8	c.737A>T	p.Tyr246Phe	missense_variant, splice_region_variant	7/27	1	NM_177438.3	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251284 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135814

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 31

ExAC AF: 0.00000824 AC: 1

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

Aug 30, 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. 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: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C15"). ClinVar contains an entry for this variant (Variation ID: 1003259). This variant has not been reported in the literature in individuals affected with DICER1-related conditions. This variant is present in population databases (rs775370673, gnomAD 0.0009%). This sequence change replaces tyrosine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 246 of the DICER1 protein (p.Tyr246Phe). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 16, 2021

The p.Y246F variant (also known as c.737A>T), located in coding exon 6 of the DICER1 gene, results from an A to T substitution at nucleotide position 737. The tyrosine at codon 246 is replaced by phenylalanine, an amino acid with highly similar properties. This amino acid position is well 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	0.18
BayesDel_addAF	Uncertain	0.022	T
BayesDel_noAF	Benign	-0.21
Cadd	Benign	19
Dann	Benign	0.97
DEOGEN2	Uncertain	0.73	D;D;D;D;.
Eigen	Benign	-0.21
Eigen_PC	Benign	-0.059
FATHMM_MKL	Uncertain	0.96	D
M_CAP	Benign	0.024	T
MetaRNN	Benign	0.32	T;T;T;T;T
MetaSVM	Benign	-0.96	T
MutationAssessor	Uncertain	2.1	M;M;M;M;M
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.72	T
PROVEAN	Uncertain	-2.7	D;D;D;D;D
REVEL	Benign	0.20
Sift	Benign	0.077	T;T;T;T;T
Sift4G	Uncertain	0.013	D;D;D;D;D
Polyphen		0.066	B;B;B;B;.
Vest4		0.49
MutPred		0.61		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		0.68
MPC		0.57
ClinPred		0.49	T
GERP RS		4.2
Varity_R		0.37
gMVP		0.47

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs775370673; hg19: chr14-95593083;