Is TERT p.Pro421Ser (c.1261C>T) pathogenic?

TERT p.Pro421Ser (c.1261C>T) is classified Uncertain significance in TERT (ClinVar, Single submitter, 1 submitter; last evaluated 2022-12-15). AlphaMissense: likely benign (0.0748); Absent from gnomAD v4.1; Associated with dyskeratosis congenita, autosomal dominant 2.

What condition is associated with TERT p.Pro421Ser (c.1261C>T)?

TERT p.Pro421Ser (c.1261C>T) is associated with dyskeratosis congenita, autosomal dominant 2, idiopathic pulmonary fibrosis (ClinVar).

How common is TERT p.Pro421Ser (c.1261C>T) in the general population?

TERT p.Pro421Ser (c.1261C>T) 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 TERT p.Pro421Ser (c.1261C>T)?

AlphaMissense predicts likely benign (score 0.0748) — an in-silico prediction, not a clinical call.

TERT p.Pro421Ser

c.1261C>T · rs773246847 · VCV946702

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0748 · ACMG-weighted

gnomAD v4.1

Not reported

no allele count reported in gnomAD v4.1 (AN 1,552,502)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

dyskeratosis congenita, autosomal dominant 2

Computational evidence

Protein change
AlphaMissense	0.0748	likely benign
REVEL	0.132	moderately benign-leaning
SaProt	LLR -7.01	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -0.51	GERP -2
Regional constraint	o/e 0.93	unconstrained · MANE · 12 kb · p 0.082 · regional, not allelic
Overall
CADD	0.814	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — a triage signal, not a reclassification

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

Population frequency

gnomAD v4.1 · exomes + genomes

No allele count reported in gnomAD v4.1 (AN 1,552,502). This is missing data, not an absence: the variant may or may not be present in gnomAD. Rarity (ACMG PM2) and BA1/BS1 cannot be assessed for it.

Variant & gene context

Gene: TERT
Protein: p.Pro421Ser
Coding: c.1261C>T
MANE Select: NM_198253
dbSNP: rs773246847
Type: single nucleotide variant
Location: chr5:1293625 (GRCh38)
Gene constraint: LOEUF 0.593 · pLI <0.01 · ClinGen HI 1/3 (gnomAD)
Structure: AlphaFold pLDDT 80.98 · 32 PDB
Residue 421: the 'required for oligomerization' region; the 'rna-interacting domain 2' region; the 'qfp motif' region

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

Disease context

dyskeratosis congenita, autosomal dominant 2 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: idiopathic pulmonary fibrosis

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

TERT p.Pro421= Likely benign ★★ same residue
TERT p.Pro421Leu Uncertain significance ★ ⚠ same residue
TERT p.Pro421Gln Uncertain significance ★ ⚠ same residue
TERT c.2130+1G>A Likely pathogenic ★★ same condition
TERT c.2130+2T>G Likely pathogenic ★★ same condition
TERT c.2131-2A>G Likely pathogenic ★★ same condition
TERT c.2286+1G>A Likely pathogenic ★★ same condition
TERT c.3157+1G>T 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/tert-p-pro421ser (accessed [today's date]).

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