NM_177438.3:c.446T>C

Variant names:

• chr14-95130185-A-G
• rs549001286
• NM_177438.3:c.446T>C

Variant summary

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

The NM_177438.3(DICER1):​c.446T>C​(p.Ile149Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000656 in 152,364 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: DICER1 NM_177438.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 8.87

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.446T>C	p.Ile149Thr	missense_variant	Exon 5 of 27	ENST00000343455.8	NP_803187.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DICER1	ENST00000343455.8	c.446T>C	p.Ile149Thr	missense_variant	Exon 5 of 27	1	NM_177438.3	ENSP00000343745.3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152246 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

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: 0.00000656 AC: 1 AN: 152364 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74512

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

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

Mar 21, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 149 of the DICER1 protein (p.Ile149Thr). This variant is present in population databases (rs549001286, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with DICER1-related conditions. ClinVar contains an entry for this variant (Variation ID: 412161). 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 with a negative predictive value of 80%. 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

Nov 15, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.I149T variant (also known as c.446T>C), located in coding exon 4 of the DICER1 gene, results from a T to C substitution at nucleotide position 446. The isoleucine at codon 149 is replaced by threonine, an amino acid with 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	Uncertain	0.51
BayesDel_addAF	Benign	-0.080	T
BayesDel_noAF	Benign	-0.18
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.47	T;T;T;T;.
Eigen	Uncertain	0.21
Eigen_PC	Uncertain	0.39
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	.;.;D;.;D
M_CAP	Benign	0.016	T
MetaRNN	Uncertain	0.61	D;D;D;D;D
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.8	L;L;L;L;L
PrimateAI	Benign	0.42	T
PROVEAN	Uncertain	-2.9	D;D;D;D;D
REVEL	Benign	0.24
Sift	Uncertain	0.0020	D;D;D;D;D
Sift4G	Uncertain	0.0050	D;D;D;D;D
Polyphen		0.015	B;B;B;B;.
Vest4		0.81
MutPred		0.63		Loss of stability (P = 0.0076);Loss of stability (P = 0.0076);Loss of stability (P = 0.0076);Loss of stability (P = 0.0076);Loss of stability (P = 0.0076);
MVP		0.64
MPC		0.68
ClinPred		0.85	D
GERP RS		5.8
Varity_R		0.65
gMVP		0.73

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: rs549001286; hg19: chr14-95596522;