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LMNB1 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

LMNB1 gene

The LMNB1 gene provides instructions for making the lamin B1 protein, a structural component of the nuclear envelope that is critical for nerve cell health.

Normal Function

The LMNB1 gene produces the lamin B1 protein, an intermediate filament protein. It serves as a scaffolding component of the nuclear lamina, a mesh-like layer attached to the inner membrane of the nuclear envelope.

Beyond providing structural stability to the nucleus, lamin B1 helps regulate the movement of molecules into and out of the nucleus. It also plays a role in DNA replication and the organization of chromosomes, which influences the activity (expression) of many genes.

Health Conditions Related to Genetic Changes

Autosomal dominant leukodystrophy with autonomic disease (ADLD)

ADLD is a condition characterized by the loss of myelin—the fatty substance that insulates nerve fibers—leading to nervous system abnormalities.

  • Causes: Nearly all cases result from an abnormal extra copy (duplication) of the LMNB1 gene, leading to an overproduction of lamin B1. In rare cases, deletions near the gene can also lead to overexpression.
  • Cellular Impact: Brain cells, particularly oligodendrocytes (which produce myelin), are highly sensitive to excess lamin B1. Increased levels cause the nuclear envelope to harden and decrease the expression of genes necessary for myelin maintenance.
  • Symptoms: Affected individuals typically experience autonomic nervous system dysfunction (e.g., bowel and bladder issues) in their thirties or forties, followed by progressive movement problems due to demyelination in the brain and spinal cord.

Other Names for This Gene

  • LMN
  • LMN2
  • LMNB

Frequently Asked Questions

The earliest signs usually involve the autonomic nervous system, which controls involuntary functions. Common initial symptoms include constipation, bladder control issues, and orthostatic hypotension (dizziness upon standing). As the condition progresses, patients may experience difficulty with balance, coordination, and speech, which are signs of demyelination in the brain and spinal cord.
Diagnosis is confirmed through genetic testing that identifies a duplication of the LMNB1 gene, which is the cause in nearly all cases. Because symptoms typically do not appear until the thirties or forties, presymptomatic testing is available for at-risk family members. This allows for early monitoring and genetic counseling, although there is currently no cure to prevent the onset of the disease.
DLD is an autosomal dominant condition, meaning only one copy of the altered gene is needed to cause the disorder. If one parent has ADLD, each child has a 50 percent chance of inheriting the gene duplication. Genetic counseling is recommended for families to understand inheritance patterns and discuss testing options for offspring.
While the primary impact is on the nervous system due to the sensitivity of oligodendrocytes to excess lamin B1, the protein is present in many cell types. However, clinical manifestations of ADLD are predominantly neurological. Research continues to explore whether subtle effects on other tissues exist, but the hallmark features remain autonomic dysfunction and progressive demyelination.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

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