CLDN19

Chr 1AR

claudin 19

Also known as: HOMG5

CLDN19 encodes claudin-19, a tight junction protein that forms paracellular channels with claudin-16 to facilitate magnesium and calcium reabsorption in the kidney and maintains barrier function in retinal pigment epithelium and Schwann cells. Mutations cause hypomagnesemia 5, renal, with ocular involvement (HOMGO), a progressive disease characterized by renal magnesium wasting, hypercalciuria, nephrocalcinosis, and severe ocular abnormalities including chorioretinal scars, macular colobomata, myopia, and nystagmus. This condition follows autosomal recessive inheritance.

OMIMResearchSummary from RefSeq, OMIM, UniProt
MultiplemechanismARLOEUF 1.081 OMIM phenotype
Clinical SummaryCLDN19
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
1.08LOEUF
pLI 0.005
Z-score 1.40
OE 0.51 (0.271.08)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
0.78Z-score
OE missense 0.81 (0.700.95)
112 obs / 137.7 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.51 (0.271.08)
00.351.4
Missense OE0.81 (0.700.95)
00.61.4
Synonymous OE0.77
01.21.6
LoF obs/exp: 5 / 9.7Missense obs/exp: 112 / 137.7Syn Z: 1.46
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveCLDN19-related hypomagnesemia with ocular involvementOTHERAR

Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.

DN
0.79top 25%
GOF
0.84top 5%
LOF
0.2092th %ile

The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.

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

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

CLDN19 · 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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