Is DICER1 p.Cys306= (c.918T>C) pathogenic?

DICER1 p.Cys306= (c.918T>C) is classified Benign/Likely benign in DICER1 (ClinVar, Multiple submitters, 3 submitters; last evaluated 2026-04-15). Very rare (popmax 0.000509%, nfe); Associated with DICER1-related tumor predisposition.

What condition is associated with DICER1 p.Cys306= (c.918T>C)?

DICER1 p.Cys306= (c.918T>C) is associated with DICER1-related tumor predisposition, hereditary neoplastic syndrome (ClinVar).

How common is DICER1 p.Cys306= (c.918T>C) in the general population?

DICER1 p.Cys306= (c.918T>C) is very rare (popmax 0.000509%, nfe) (gnomAD).

How is DICER1 tumor-predisposition syndrome inherited?

Typically Autosomal dominant (Orphanet). A genetic counselor can assess individual risk for a family.

DICER1 p.Cys306=

c.918T>C · rs886943453 · VCV417136

Benign/Likely benign Multiple submitters

Classification

Benign/Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

gnomAD v4.1

Rare

very rare (popmax 0.000509%, nfe)

Conditions

DICER1-related tumor predisposition

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -1.3	GERP -3.5
Overall
CADD	4.158	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000509% European (non-Finnish) · 6/1,179,498 alleles

Filtering AF 0.000183% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00012%

Overall 0.000372% 6/1,612,998 alleles · very rare

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: DICER1
Protein: p.Cys306=
Coding: c.918T>C
MANE Select: NM_177438
dbSNP: rs886943453
Type: single nucleotide variant
Location: chr14:95124654 (GRCh38)
Gene constraint: LOEUF 0.275 · pLI 1.00 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 67.89 · 21 PDB
Residue 306: an α-helix; the 'required for interaction with prkra and tarbp2' region

Full DICER1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Also linked: hereditary neoplastic syndrome

For DICER1 tumor-predisposition syndrome (Orphanet):

Inheritance: Autosomal dominant
Onset: Adolescent, Adult, Childhood
Prevalence: <1 / 1 000 000 (Worldwide)

Similar variants

DICER1 p.Cys306Ser Uncertain significance ★ ⚠ same residue
DICER1 p.Cys306fs Pathogenic ★ same residue
DICER1 c.1509+16A>G Likely pathogenic ★★★ same condition
DICER1 c.1752+213A>G Likely pathogenic ★★★ same condition
DICER1 c.1753-9A>G Likely pathogenic ★★★ same condition
DICER1 c.1907+1G>A Pathogenic ★★★ same condition
DICER1 c.1908-3C>G Likely pathogenic ★★★ same condition
DICER1 c.2256+5G>A Likely pathogenic ★★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/dicer1-p-cys306 (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown