Early and late manifestations of neuropathy due to HSPB1 mutation in the Jewish Iranian population

A novel HSPB1S139F mouse model of Charcot-Marie-Tooth Disease

Charcot-Marie-Tooth Disease (CMT) is a commonly inherited peripheral polyneuropathy. Clinical manifestations for this disease include symmetrical distal polyneuropathy, altered deep tendon reflexes, distal sensory loss, foot deformities, and gait abnormalities. Genetic mutations in heat shock proteins have been linked to CMT2. Specifically, mutations in the heat shock protein B1 (HSPB1) gene encoding for heat shock protein 27 (Hsp27) have been linked to CMT2F and distal hereditary motor and sensory neuropathy type 2B (dHMSN2B) subtype. The goal of the study was to examine the role of an endogenous mutation in HSPB1 in vivo and to define the effects of this mutation on motor function and pathology in a novel animal model. As sphingolipids have been implicated in hereditary and sensory neuropathies, we examined sphingolipid metabolism in central and peripheral nervous tissues in 3-month-old HspS139F mice. Though sphingolipid levels were not altered in sciatic nerves from HspS139F mice, ceramides and deoxyceramides, as well as sphingomyelins (SMs) were elevated in brain tissues from HspS139F mice. Histology was utilized to further characterize HspS139F mice. HspS139F mice exhibited no alterations to the expression and phosphorylation of neurofilaments, or in the expression of acetylated α-tubulin in the brain or sciatic nerve. Interestingly, HspS139F mice demonstrated cerebellar demyelination. Locomotor function, grip strength and gait were examined to define the role of HspS139F in the clinical phenotypes associated with CMT2F. Gait analysis revealed no differences between HspWT and HspS139F mice. However, both coordination and grip strength were decreased in 3-month-old HspS139F mice. Together these data suggest that the endogenous S139F mutation in HSPB1 may serve as a mouse model for hereditary and sensory neuropathies such as CMT2F.

Hereditary motor and sensory neuropathy with SOD1-mutant: A case report

RATIONALE

Hereditary motor-sensory peripheral neuropathy, or Charot-Marie-Tooth (CMT) Charcot-Marie-Tooth disease is an inherited peripheral neuropathy characterized by progressive limb weakness and muscle atrophy. As the disease progresses, sensory and autonomic involvement may occur. We report a case of CMT associated with SOD1 gene mutation, in order to provide new ideas for clinical disease diagnosis.

PATIENT CONCERNS

A 50-years-old female patient was admitted to the hospital with "progressive weakness of the right lower extremity for 5 years, aggravating, and weakness of the left lower extremity for 4 months".

DIAGNOSIS

The patient was diagnosed CMT.

INTERVENTION

Nerve nutrition and rehabilitation therapy were given, but the patient's condition still did not improve significantly.

OUTCOMES

The improvement of symptoms was not obvious.

LESSONS

The clinical manifestations and electromyography results of this patient are consistent with the characteristics of CMT. The peripheral nerve-related hereditary gene test found mutation in SOD1. It is possible that this mutation is linked to CMT. The disease is a neurodegenerative disease, that may be slowed by physical therapy and rehabilitation, but could not be healed.

Heterogeneous Clinical Phenotypes of dHMN Caused by Mutation in HSPB1 Gene: A Case Series

Mutations in HSPB1 are known to cause Charcot-Marie-Tooth disease type 2F (CMT2F) and distal hereditary motor neuropathy (dHMN). In this study, we presented three patients with mutation in HSPB1 who were diagnosed with dHMN. Proband 1 was a 14-year-old male with progressive bilateral lower limb weakness and walking difficulty for four years. Proband 2 was a 65-year-old male with chronic lower limb weakness and restless legs syndrome from the age of 51. Proband 3 was a 50-year-old female with progressive weakness, lower limbs atrophy from the age of 44. The nerve conduction studies (NCS) suggested axonal degeneration of the peripheral motor nerves and needle electromyography (EMG) revealed chronic neurogenic changes in probands. Open sural nerve biopsy for proband 2 and the mother of proband 1 showed mild to moderate loss of myelinated nerve fibers with some nerve fiber regeneration. A novel p.V97L in HSPB1 was identified in proband 3, the other two variants (p.P182A and p.R127W) in HSPB1 have been reported previously. The functional studies showed that expressing mutant p.V97L HSPB1 in SH-SY5Y cells displayed a decreased cell activity and increased apoptosis under stress condition. Our study expands the clinical phenotypic spectrum and etiological spectrum of HSPB1 mutation.