rs758932000

Positions:

• chr14-95111345-G-A
• chr14-95111345-G-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 1P and 4B. PP2 BS2

The NM_177438.3(DICER1):​c.2228C>T​(p.Thr743Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,870 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. T743A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: DICER1 NM_177438.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.96

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 Likely_benign. Variant got -3 ACMG points.

• PP2: Missense variant where missense usually causes diseases, DICER1
• BS2: High AC in GnomAdExome4 at 8 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DICER1	NM_177438.3	c.2228C>T	p.Thr743Met	missense_variant	14/27	ENST00000343455.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DICER1	ENST00000343455.8	c.2228C>T	p.Thr743Met	missense_variant	14/27	1	NM_177438.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000795 AC: 2 AN: 251466 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135910

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.0000992

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461870 Hom.: 0 Cov.: 32 AF XY: 0.00000963 AC XY: 7 AN XY: 727232

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.000111 Hom.: 0

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

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

Nov 02, 2023

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 743 of the DICER1 protein (p.Thr743Met). This variant is present in population databases (rs758932000, gnomAD 0.01%). 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: 412048). 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 expected to disrupt DICER1 protein function with a positive 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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 01, 2023

The p.T743M variant (also known as c.2228C>T), located in coding exon 13 of the DICER1 gene, results from a C to T substitution at nucleotide position 2228. The threonine at codon 743 is replaced by methionine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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	Pathogenic	0.97
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.020
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.81	D;D;D;D;.
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Benign	0.075	D
MetaRNN	Uncertain	0.44	T;T;T;T;T
MetaSVM	Benign	-0.48	T
MutationAssessor	Benign	1.8	L;L;L;L;L
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Uncertain	-4.3	D;D;D;D;D
REVEL	Uncertain	0.34
Sift	Uncertain	0.0010	D;D;D;D;D
Sift4G	Uncertain	0.0020	D;D;D;D;D
Polyphen		1.0	D;D;D;D;.
Vest4		0.61
MutPred		0.22		Loss of phosphorylation at T743 (P = 0.0016);Loss of phosphorylation at T743 (P = 0.0016);Loss of phosphorylation at T743 (P = 0.0016);Loss of phosphorylation at T743 (P = 0.0016);Loss of phosphorylation at T743 (P = 0.0016);
MVP		0.69
MPC		1.4
ClinPred		0.99	D
GERP RS		3.8
Varity_R		0.42
gMVP		0.65

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		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: rs758932000; hg19: chr14-95577682;