TTYH2

Chr 17

tweety family member 2

Also known as: C17orf29

The protein functions as a calcium-activated large conductance chloride channel and a volume-regulated anion channel that mediates regulatory volume decrease in the brain through efflux of chloride and glutamate. Based on the extremely low probability of loss-of-function intolerance (pLI = 0.0001) and predicted gain-of-function mechanism, TTYH2 mutations are not currently associated with established human disease. Loss-of-function variants in this gene appear to be well-tolerated in the general population.

Summary from RefSeq, UniProt, Mechanism
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0
Active trials
2
Pubs (1 yr)
0
P/LP submissions
P/LP missense
0.65
LOEUF
Multiple*
Mechanism· predicted
Clinical SummaryTTYH2
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.65LOEUF
pLI 0.000
Z-score 3.02
OE 0.40 (0.260.65)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
0.36Z-score
OE missense 0.94 (0.861.04)
311 obs / 329.2 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.40 (0.260.65)
00.351.4
Missense OE0.94 (0.861.04)
00.61.4
Synonymous OE1.02
01.21.6
LoF obs/exp: 12 / 29.8Missense obs/exp: 311 / 329.2Syn Z: -0.15
DN
0.74top 25%
GOF
0.80top 10%
LOF
0.2189th %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

TTYH2 · protein map & ClinVar variants

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

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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