CRYM

Chr 16AD

crystallin mu

Also known as: DFNA40, THBP

The protein functions as an NADPH-dependent reductase that catalyzes the reduction of cyclic ketimine substrates, playing a central role in lysine and glutamate metabolism. Mutations cause autosomal dominant non-syndromic deafness (DFNA40). The gene is not highly constrained against loss-of-function variants, with hearing loss being the primary clinical manifestation.

OMIMResearchSummary from RefSeq, OMIM, UniProt
MultiplemechanismADLOEUF 0.761 OMIM phenotype
Clinical SummaryCRYM
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Gene-Disease Validity (ClinGen)
nonsyndromic genetic hearing loss · ADLimited

Limited evidence — not for standalone diagnostic reporting

Population Constraint (gnomAD)
Low constraint (pLI 0.03) — 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
0.76LOEUF
pLI 0.026
Z-score 2.21
OE 0.36 (0.190.76)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
0.98Z-score
OE missense 0.79 (0.690.91)
138 obs / 174.6 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.36 (0.190.76)
00.351.4
Missense OE0.79 (0.690.91)
00.61.4
Synonymous OE0.86
01.21.6
LoF obs/exp: 5 / 13.9Missense obs/exp: 138 / 174.6Syn Z: 0.89
DN
0.6744th %ile
GOF
0.7126th %ile
LOF
0.2777th %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

CRYM · protein map & ClinVar variants

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

3D Protein StructureAlphaFold

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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