rs1555376402

chr14-95132626-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_177438.3(DICER1):c.196A>G(p.Thr66Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 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. T66I) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: DICER1 NM_177438.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.68

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 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, DICER1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.853

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DICER1	NM_177438.3	c.196A>G	p.Thr66Ala	missense_variant	3/27	ENST00000343455.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DICER1	ENST00000343455.8	c.196A>G	p.Thr66Ala	missense_variant	3/27	1	NM_177438.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

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

Dec 26, 2021

This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 66 of the DICER1 protein (p.Thr66Ala). 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. ClinVar contains an entry for this variant (Variation ID: 543652). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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

Jul 06, 2021

The p.T66A variant (also known as c.196A>G), located in coding exon 2 of the DICER1 gene, results from an A to G substitution at nucleotide position 196. The threonine at codon 66 is replaced by alanine, an amino acid with similar 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	Benign	0.12
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.40
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.45	T;T;T;T;.;T;T
Eigen	Uncertain	0.41
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Uncertain	0.96	D
M_CAP	Pathogenic	0.43	D
MetaRNN	Pathogenic	0.85	D;D;D;D;D;D;D
MetaSVM	Uncertain	0.64	D
MutationAssessor	Pathogenic	4.1	H;H;H;H;H;.;.
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Pathogenic	0.86	D
PROVEAN	Benign	-1.6	N;N;N;N;N;D;D
REVEL	Uncertain	0.45
Sift	Benign	0.23	T;T;T;T;T;D;D
Sift4G	Benign	0.45	T;T;T;T;T;.;.
Polyphen		0.21	B;B;B;B;.;.;.
Vest4		0.96
MutPred		0.83		Loss of methylation at K70 (P = 0.0639);Loss of methylation at K70 (P = 0.0639);Loss of methylation at K70 (P = 0.0639);Loss of methylation at K70 (P = 0.0639);Loss of methylation at K70 (P = 0.0639);Loss of methylation at K70 (P = 0.0639);Loss of methylation at K70 (P = 0.0639);
MVP		0.99
MPC		0.57
ClinPred		0.98	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.21
gMVP		0.86

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: rs1555376402; hg19: chr14-95598963;