CRLF2

Chr Y

cytokine receptor like factor 2

Also known as: CRL2, CRLF2Y, TSLPR

The protein functions as a receptor for thymic stromal lymphopoietin (TSLP) and forms a complex with IL7R to activate STAT3, STAT5, and JAK2 pathways that control cell proliferation and hematopoietic system development. Rearrangements of this gene with immunoglobulin heavy chain or P2RY8 genes are associated with B-progenitor acute lymphoblastic leukemia and Down syndrome-associated ALL. The gene shows low constraint against loss-of-function variants, consistent with its primary role in hematologic malignancies rather than developmental disorders.

OMIMResearchSummary from RefSeq, UniProt
MultiplemechanismLOEUF 1.40
Clinical SummaryCRLF2
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
💊
Clinical Trials
1 active or recruiting trial — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.40LOEUF
pLI 0.000
Z-score 0.52
OE 0.84 (0.531.40)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
-0.85Z-score
OE missense 1.20 (1.061.35)
178 obs / 148.7 exp
Tolerant

Tolerant to missense variation

Observed / Expected Ratios
LoF OE0.84 (0.531.40)
00.351.4
Missense OE1.20 (1.061.35)
00.61.4
Synonymous OE1.17
01.21.6
LoF obs/exp: 11 / 13.0Missense obs/exp: 178 / 148.7Syn Z: -1.07
DN
0.6840th %ile
GOF
0.75top 25%
LOF
0.2580th %ile

This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function and dominant-negative). Both the Badonyi & Marsh prediction and the broader genomic evidence point to gain-of-function as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

GOFprediction above median
DNprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

CRLF2 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold
Clinical Literature
Open Research Assistant →