Is ITK p.Lys248Ter (c.742A>T) pathogenic?

ITK p.Lys248Ter (c.742A>T) is classified Pathogenic in ITK (ClinVar, Single submitter, 1 submitter; last evaluated 2023-02-16). Very rare (popmax 0.000339%, nfe); Associated with lymphoproliferative syndrome 1.

What condition is associated with ITK p.Lys248Ter (c.742A>T)?

ITK p.Lys248Ter (c.742A>T) is associated with lymphoproliferative syndrome 1 (ClinVar).

How common is ITK p.Lys248Ter (c.742A>T) in the general population?

ITK p.Lys248Ter (c.742A>T) is very rare (popmax 0.000339%, nfe) (gnomAD).

How is Combined immunodeficiency due to ITK deficiency inherited?

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

ITK p.Lys248Ter

c.742A>T · rs1754674801 · VCV2148272

Pathogenic Single submitter

Classification

Pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

Consequence

nonsense (stop-gain)

predicted LoF

gnomAD v4.1

Rare

very rare (popmax 0.000339%, nfe)

Conditions

lymphoproliferative syndrome 1

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Consequence	nonsense (stop-gain)	predicted loss-of-function
NMD	predicted	premature termination codon in exon 8 of 17
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 11	GERP 1.7, phastCons 1
Overall
CADD	39.0	PHRED · no single calibrated threshold — expert panels disagree

Predicted loss-of-function is descriptive, not an applied PVS1 code.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000339% European (non-Finnish) · 4/1,178,312 alleles

Filtering AF 7.9e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 5.4e-05%

Overall 0.00031% 5/1,611,798 alleles · very rare

Ancestry group	Frequency	1 in
Remaining individualsnot grpmax-eligible	0.0016%	62,384
European (non-Finnish)grpmax	0.000339%	294,578

Remaining individuals shows a higher raw frequency than the grpmax group above it. gnomAD excludes bottlenecked groups — Finnish, Ashkenazi Jewish, Amish and “Remaining individuals” — from grpmax, because founder effects make their frequencies unrepresentative for filtering. The table is sorted by frequency, so an excluded group can sit above the grpmax row.

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: ITK
Protein: p.Lys248Ter
Coding: c.742A>T
MANE Select: NM_005546
dbSNP: rs1754674801
Type: single nucleotide variant
Location: chr5:157232368 (GRCh38)
Gene constraint: LOEUF 0.644 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 84.82 · 37 PDB
Residue 248: the sh2 domain

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

Disease context

lymphoproliferative syndrome 1 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Combined immunodeficiency due to ITK deficiency (Orphanet):

Inheritance: Autosomal recessive
Onset: Adolescent, Childhood

Similar variants

ITK c.851+5G>A Uncertain significance ★★ same condition
ITK p.Ala191Thr Uncertain significance ★★ ⚠ same condition
ITK p.Ala261Thr Uncertain significance ★★ ⚠ same condition
ITK p.Ala308Ser Uncertain significance ★★ ⚠ same condition
ITK p.Ala345Val Uncertain significance ★★ ⚠ same condition
ITK p.Ala471Thr Uncertain significance ★★ ⚠ same condition
ITK p.Ala525Thr Uncertain significance ★★ ⚠ same condition
ITK p.Ala583Val 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/itk-p-lys248ter (accessed [today's date]).

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