Animal models for inherited peripheral neuropathies

Area of Science:

• Neurogenetics
• Molecular Neurobiology
• Animal Models of Neurological Disease

Background:

• Inherited demyelinating peripheral neuropathies are linked to mutations in myelin genes.
• Key genes involved include PMP22, P0, and connexin 32, responsible for Charcot-Marie-Tooth (CMT) subtypes CMT1A, CMT1B, and CMTX.
• Gene dosage alterations in PMP22 cause hereditary neuropathy with liability to pressure palsies (HNPP), and point mutations in PMP22 and P0 lead to Dejerine-Sottas (DS) neuropathy.

Purpose of the Study:

• To evaluate the suitability of spontaneous and genetically engineered rodent mutants as models for inherited demyelinating neuropathies.
• To explore how these models can advance the understanding and treatment of diseases like CMT, HNPP, and DS.

Main Methods:

• Utilizing spontaneous rodent mutants (e.g., Trembler-J, Trembler) with specific point mutations in myelin genes.
• Employing genetically engineered rodents with altered expression (over/under-expression) or deficiency of myelin genes (PMP22, P0, Cx32).
• Comparing the pathological alterations in these mutants to human patient phenotypes.

Main Results:

• Spontaneous mutants with PMP22 mutations model aspects of CMT1A and DS neuropathies.
• Engineered mutants with altered PMP22 gene dosage mimic HNPP.
• Mutants deficient in P0 or Cx32 replicate pathologies seen in CMT1B, DS, and CMTX patients, respectively.

Conclusions:

• Rodent models accurately reflect the pathology of various inherited demyelinating neuropathies.
• These models are crucial for developing therapeutic strategies, identifying environmental risk factors, and advancing gene therapy for these conditions.