ClinVar Genomic variation as it relates to human health

The NM_177438.2:c.5038A>G (p.Lys1680Glu) variant in DICER1 is a missense variant predicted to cause substitution of lysine by glutamic acid at amino acid 1680 (p.Lys1680Glu). The total allele frequency in gnomAD v4.1.0 is 0.000003420 (5/1461878 alleles) with highest population minor allele frequencies of 0.00004967 (3/60396 alleles) and 0.000001799 (2/1111996) in a population of undescribed ancestry and the European (non-Finnish) population, respectively (PM2_Supporting, BS1, and BA1 are not met). The computational predictor REVEL gives a score of 0.697, which is neither above nor below the thresholds predicting a damaging or benign impact on DICER1 function (PP3 and BP4 not met). 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 data). In summary, this variant meets the criteria to be classified as Uncertain Significance for DICER1-related tumor predisposition based on the ACMG/AMP criteria applied, as specified by the ClinGen DICER1 VCEP: BS2_Supporting. (Bayesian Points: -1; VCEP specifications version 1.3.0; 02/27/2024)

This sequence change replaces lysine, which is basic and polar, with glutamic acid, which is acidic and polar, at codon 1680 of the DICER1 protein (p.Lys1680Glu). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This missense change has been observed in individual(s) with unspecified cancer (PMID: 28873162). ClinVar contains an entry for this variant (Variation ID: 412143). 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.

The p.K1680E variant (also known as c.5038A>G), located in coding exon 22 of the DICER1 gene, results from an A to G substitution at nucleotide position 5038. The lysine at codon 1680 is replaced by glutamic acid, 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.

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Observed in at least one individual with advanced cancer undergoing multigene hereditary cancer panel testing (PMID: 28873162); This variant is associated with the following publications: (PMID: 28873162)

Variant interpreted as Uncertain significance and reported on 09-01-2018 by Lab Invitae. GenomeConnect-Invitae Patient Insights Network assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. Registry team members make no attempt to reinterpret the clinical significance of the variant. Phenotypic details are available under supporting information.