Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1PM2PM5PP2PP3_Moderate
The NM_177438.3(DICER1):āc.5441C>Gā(p.Ser1814Trp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,820 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S1814L) has been classified as Pathogenic.
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]
Verdict is Likely_pathogenic. Variant got 9 ACMG points.
PM1
In a helix (size 16) in uniprot entity DICER_HUMAN there are 6 pathogenic changes around while only 0 benign (100%) in NM_177438.3
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr14-95091289-G-A is described in Lovd as [Pathogenic].
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.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.924