NM_177438.3:c.2335A>G

Variant names:

• chr14-95108425-T-C
• rs1555370931
• NM_177438.3:c.2335A>G

Variant summary

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

The NM_177438.3(DICER1):​c.2335A>G​(p.Thr779Ala) 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 (★).

• 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: 7.73

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 in the DICER1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 43 curated pathogenic missense variants (we use a threshold of 10). The gene has 111 curated benign missense variants. Gene score misZ: 4.2261 (above the threshold of 3.09). Trascript score misZ: 6.1353 (above the threshold of 3.09). GenCC associations: The gene is linked to 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DICER1	NM_177438.3	c.2335A>G	p.Thr779Ala	missense_variant	Exon 15 of 27	ENST00000343455.8	NP_803187.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DICER1	ENST00000343455.8	c.2335A>G	p.Thr779Ala	missense_variant	Exon 15 of 27	1	NM_177438.3	ENSP00000343745.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

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

Sep 10, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine with alanine at codon 779 of the DICER1 protein (p.Thr779Ala). The threonine residue is highly conserved and there is a small physicochemical difference between threonine and alanine. 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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. -

Hereditary cancer-predisposing syndrome Uncertain:1

Jan 05, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.T779A variant (also known as c.2335A>G), located in coding exon 14 of the DICER1 gene, results from an A to G substitution at nucleotide position 2335. The threonine at codon 779 is replaced by alanine, an amino acid with similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.070
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.25	T;T;T;T;.
Eigen	Uncertain	0.25
Eigen_PC	Uncertain	0.30
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.90	.;.;D;.;D
M_CAP	Benign	0.033	D
MetaRNN	Uncertain	0.44	T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.0	N;N;N;N;N
PrimateAI	Pathogenic	0.83	D
PROVEAN	Benign	-0.40	N;N;N;N;N
REVEL	Benign	0.18
Sift	Benign	0.18	T;T;T;T;T
Sift4G	Benign	0.28	T;T;T;T;T
Polyphen		0.96	D;D;D;D;.
Vest4		0.63
MutPred		0.39		Loss of glycosylation at T779 (P = 0.0249);Loss of glycosylation at T779 (P = 0.0249);Loss of glycosylation at T779 (P = 0.0249);Loss of glycosylation at T779 (P = 0.0249);Loss of glycosylation at T779 (P = 0.0249);
MVP		0.81
MPC		1.3
ClinPred		0.62	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.29
gMVP		0.63

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs1555370931; hg19: chr14-95574762;