rs150883389
Variant summary
Our verdict is Uncertain significance. The variant received -2 ACMG points: 0P and 2B. BS2_SupportingBP4
This summary comes from the ClinGen Evidence Repository: The NM_177438.2:c.4423A>G variant in DICER1 is a missense variant predicted to cause substitution of threonine by alanine at amino acid 1475 (p.Thr1475Ala). This variant was observed in a proband with medulloepithelioma, type unspecified (PS4 not met; Internal lab contributor). This variant has been seen in 10 or more unrelated females without tumors through age 50 in at least one testing laboratory (BS2_Supporting; Internal lab contributors). The highest population minor allele frequency in gnomAD v4.1.0 is 0.0003287 (2/6084 alleles) in the Middle Eastern population (PM2_Supporting, BS1, and BA1 are not met). In silico tools predict no damaging impact of the variant on protein function (REVEL: 0.058; MaxEntScan and SpliceAI: no effect on splicing) (BP4). Though this variant meets the criteria to be classified as Likely Benign for DICER1-related tumor predisposition based on the ACMG/AMP criteria applied (BS2_Supporting, BP4), the ClinGen DICER1 VCEP has decided to override classification to Uncertain Significance due to the potential observation of ciliary body medulloepithelioma (a high-specificity phenotype) in a proband with limited available clinical data. (Bayesian Points: -2; VCEP specifications version 1.3.0; 02/27/2024) LINK:https://erepo.genome.network/evrepo/ui/classification/CA7330848/MONDO:0100216/024
Frequency
Consequence
NM_177438.3 missense
Scores
Clinical Significance
Conservation
Publications
- DICER1-related tumor predispositionInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- pleuropulmonary blastomaInheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- DICER1 syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- global developmental delay - lung cysts - overgrowth - Wilms tumor syndromeInheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
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ACMG classification
Our verdict: Uncertain_significance. The variant received -2 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| DICER1 | NM_177438.3 | c.4423A>G | p.Thr1475Ala | missense_variant | Exon 23 of 27 | ENST00000343455.8 | NP_803187.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| DICER1 | ENST00000343455.8 | c.4423A>G | p.Thr1475Ala | missense_variant | Exon 23 of 27 | 1 | NM_177438.3 | ENSP00000343745.3 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152170Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000796 AC: 2AN: 251364 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.0000103 AC: 15AN: 1461836Hom.: 0 Cov.: 32 AF XY: 0.00000825 AC XY: 6AN XY: 727226 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152170Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74340 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
DICER1-related tumor predisposition Uncertain:2
The NM_177438.2:c.4423A>G variant in DICER1 is a missense variant predicted to cause substitution of threonine by alanine at amino acid 1475 (p.Thr1475Ala). This variant was observed in a proband with medulloepithelioma, type unspecified (PS4 not met; Internal lab contributor). This variant has been seen in 10 or more unrelated females without tumors through age 50 in at least one testing laboratory (BS2_Supporting; Internal lab contributors). The highest population minor allele frequency in gnomAD v4.1.0 is 0.0003287 (2/6084 alleles) in the Middle Eastern population (PM2_Supporting, BS1, and BA1 are not met). In silico tools predict no damaging impact of the variant on protein function (REVEL: 0.058; MaxEntScan and SpliceAI: no effect on splicing) (BP4). Though this variant meets the criteria to be classified as Likely Benign for DICER1-related tumor predisposition based on the ACMG/AMP criteria applied (BS2_Supporting, BP4), the ClinGen DICER1 VCEP has decided to override classification to Uncertain Significance due to the potential observation of ciliary body medulloepithelioma (a high-specificity phenotype) in a proband with limited available clinical data. (Bayesian Points: -2; VCEP specifications version 1.3.0; 02/27/2024) -
This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 1475 of the DICER1 protein (p.Thr1475Ala). This variant is present in population databases (rs150883389, gnomAD 0.0009%). 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: 477204). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt DICER1 protein function with a negative predictive value of 95%. 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:2
The p.T1475A variant (also known as c.4423A>G), located in coding exon 22 of the DICER1 gene, results from an A to G substitution at nucleotide position 4423. The threonine at codon 1475 is replaced by alanine, an amino acid with similar properties. This amino acid position is not 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. -
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at