PURPOSE:
Charcot-Marie-Tooth disease type 2A (CMT2A) is caused by
mutations in the mitofusin 2 (MFN2)
genes associated with variable
central nervous system (CNS) involvement. The authors
report a case of a middle-
aged woman with genetically confirmed CMT type 2 (CMT2), combined with delayed-onset bilateral
optic neuropathy. CASE
SUMMARY:
A 47-year-old
woman presented with complaints of subacute decrease of
visual acuity in both
eyes. Her corrected
visual acuity was 20/200 in the right
eye and 20/320 in the left
eye. Fundus photographs revealed bilateral disc
pallor and diffuse
retinal nerve fiber layer defects. No papillomacular bundle defect was observed. Goldmann
perimetry showed
central scotoma in both
eyes. She had suffered from
muscle wasting of the
legs and
foot deformities such as high arches and
hammer toes since childhood and required a
wheelchair for
ambulation. A series of CMT
gene mutation tests revealed an MFN2
gene mutation, c.617C>T (p.Thr206Ile), and the
patient was diagnosed with CMT2A.
CONCLUSIONS:
Charcot-Marie-Tooth disease is a common inherited neuromuscular disorder and CMT2A, an axonal CMT neuropathy, is associated with bilateral
optic neuropathy. Therefore, suspecting CMT and testing for
gene mutations as part of the
work-up in
patients with subacute bilateral
optic neuropathy associated with
peripheral neuropathy is critical.