Is DKC1 p.Cys74Arg (c.220T>C) pathogenic?

DKC1 p.Cys74Arg (c.220T>C) is classified Uncertain significance in DKC1 (ClinVar, Single submitter, 1 submitter; last evaluated 2021-07-12). AlphaMissense: ambiguous (0.5344); Absent from gnomAD v4.1; Associated with dyskeratosis congenita.

What condition is associated with DKC1 p.Cys74Arg (c.220T>C)?

DKC1 p.Cys74Arg (c.220T>C) is associated with dyskeratosis congenita (ClinVar).

How common is DKC1 p.Cys74Arg (c.220T>C) in the general population?

DKC1 p.Cys74Arg (c.220T>C) is absent from gnomAD v4.1 (gnomAD).

How is Dyskeratosis congenita inherited?

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

What do computational predictors say about DKC1 p.Cys74Arg (c.220T>C)?

AlphaMissense predicts ambiguous (score 0.5344) — an in-silico prediction, not a clinical call.

DKC1 p.Cys74Arg

c.220T>C · rs2148509751 · VCV1444615

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

ambiguous

0.5344 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

dyskeratosis congenita

Computational evidence

Protein change
AlphaMissense	0.5344	ambiguous
REVEL	0.474	indeterminate
SaProt	LLR -5.98	tolerated
Splicing
SpliceAI	<0.2	all four deltas below 0.2 · T>G here scores Δ0.71 · evaluated, not missing
Constraint at this position
Conservation	phyloP 6.1	GERP 3.9, phastCons 1
Regional constraint	o/e 0.35	constrained · MANE · 4,035 bp · p 1.8e-12 · regional, not allelic
Overall
CADD	19.49	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: DKC1
Protein: p.Cys74Arg
Coding: c.220T>C
MANE Select: NM_001363
dbSNP: rs2148509751
Type: single nucleotide variant
Location: chrX:154765955 (GRCh38)
Structure: AlphaFold pLDDT 79.74 · 7 PDB

Full DKC1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

dyskeratosis congenita — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Dyskeratosis congenita (Orphanet):

Inheritance: Autosomal dominant, Autosomal recessive, X-linked recessive
Onset: Adolescent, Adult, Childhood, Infancy, Neonatal
Prevalence: 1-9 / 1 000 000 (Europe)

Similar variants

DKC1 p.Ala353Val Pathogenic ★★ ⚠ same condition
DKC1 p.Asn63Lys Pathogenic/Likely pathogenic ★★ ⚠ same condition
DKC1 p.Thr49Met Pathogenic ★★ ⚠ same condition
DKC1 p.Thr66Ala Pathogenic/Likely pathogenic ★★ ⚠ same condition
DKC1 c.1339-10T>G Uncertain significance ★★ same condition
DKC1 c.16+5G>A Uncertain significance ★★ same condition
DKC1 c.640+3G>A Uncertain significance ★★ same condition
DKC1 p.Ala162Thr Uncertain significance ★★ ⚠ 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/dkc1-p-cys74arg (accessed [today's date]).

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