Is TYK2 p.Pro646= (c.1938T>C) pathogenic?

TYK2 p.Pro646= (c.1938T>C) is classified Likely benign in TYK2 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-01-13). Absent from gnomAD v4.1; Associated with immunodeficiency 35.

What condition is associated with TYK2 p.Pro646= (c.1938T>C)?

TYK2 p.Pro646= (c.1938T>C) is associated with immunodeficiency 35 (ClinVar).

How common is TYK2 p.Pro646= (c.1938T>C) in the general population?

TYK2 p.Pro646= (c.1938T>C) is absent from gnomAD v4.1 (gnomAD).

TYK2 p.Pro646=

Q: How is Susceptibility to infection due to TYK2 deficiency inherited?

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

c.1938T>C · rs2145214439 · VCV1122924

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

immunodeficiency 35

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	<0.2	no splice effect predicted · four deltas, not one · how we know
Constraint at this position
Conservation	phyloP -1.4	GERP -4.4
Overall
CADD	0.527	PHRED · no single calibrated threshold — expert panels disagree

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: TYK2
Protein: p.Pro646=
Coding: c.1938T>C
MANE Select: NM_003331
dbSNP: rs2145214439
Type: single nucleotide variant
Location: chr19:10361791 (GRCh38)
Gene constraint: LOEUF 0.626 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 82.69 · 52 PDB
Residue 646: the protein kinase 1 domain

Full TYK2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

immunodeficiency 35 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Susceptibility to infection due to TYK2 deficiency (Orphanet):

Inheritance: Autosomal recessive
Onset: Infancy

Similar variants

TYK2 p.Pro646Ser Uncertain significance ★ ⚠ same residue
TYK2 p.Arg609Ter Pathogenic/Likely pathogenic ★★ same condition
TYK2 p.Trp798Ter Pathogenic ★★ same condition
TYK2 p.Ala1004Gly Uncertain significance ★★ ⚠ same condition
TYK2 p.Ala1026Thr Uncertain significance ★★ ⚠ same condition
TYK2 p.Ala165Thr Uncertain significance ★★ ⚠ same condition
TYK2 p.Ala195Ser Uncertain significance ★★ ⚠ same condition
TYK2 p.Ala195Thr 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/tyk2-p-pro646 (accessed [today's date]).

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