LMNB1

Chr 5AD

lamin B1

Also known as: ADLD, LMN, LMN2, LMNB, MCPH26

The protein is a B-type lamin that forms part of the nuclear lamina structure. Duplications cause autosomal dominant adult-onset leukodystrophy (ADLD), while other mutations result in autosomal dominant primary microcephaly 26. The pathogenic mechanism involves a dominant-negative effect where mutant protein disrupts normal nuclear envelope function.

OMIMResearchSummary from RefSeq, OMIM, UniProt, Mechanism
MultiplemechanismADLOEUF 0.411 OMIM phenotype
Clinical SummaryLMNB1
🧬
Gene-Disease Validity (ClinGen)
microcephaly 26, primary, autosomal dominant · ADDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Moderately constrained gene (pLI 0.55) — some intolerance to loss-of-function variants.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Moderate LoF intolerance
LoF Constraint
0.41LOEUF
pLI 0.555
Z-score 3.92
OE 0.21 (0.110.41)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
1.63Z-score
OE missense 0.74 (0.660.82)
229 obs / 309.5 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.21 (0.110.41)
00.351.4
Missense OE0.74 (0.660.82)
00.61.4
Synonymous OE0.95
01.21.6
LoF obs/exp: 6 / 28.6Missense obs/exp: 229 / 309.5Syn Z: 0.41
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveLMNB1-related developmental disorderOTHERAD
DN
0.83top 10%
GOF
0.7127th %ile
LOF
0.3453th %ile

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

DNprediction above median · 1 literature citation
GOFprediction 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.

Literature Evidence

DNDominant negative mutant lamin B proteins that disrupt lamin B assembly in interphase nuclei also disrupted spindle assembly in mitosis.PMID:16543417

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

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

LMNB1 · 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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