Pediatric Inherited Peripheral Neuropathies Flashcards
What is the most heritable peripheral neuropathy?
Charcot-Marie-Tooth (CMT), or hereditary motor and sensory neuropathies (HMSNs)
Classic presentation of CMT?
progressive motor and sensory nerve impairment with onset in the 1st or second decade of life
- insidious progressive muscle weakness - distal strength affected more than proximal
- atrophy of hand intrinsic muscles
- Pes cavus deformity
- stocking glove distribution sensory loss
Inheritance pattern of CMT1?
Autosomal dominant transmission
Is CMT1 demyelinating or axonal?
Demyelinating
Early predilection for weakness and atrophy of the anterior compartment peroneal-supplied muscles is associated with which variant of CMT?
CMT1
Which gene is associated w/ CMT1A?
PMP-22
CMT1A accounts for which percentage of CMT cases?
80%
What is the inheritance pattern for CMT2?
Autosomal dominant AND autosomal recessive inheritance
Is CMT2 demyelinating or axonal?
axonal pathology
What characteristics can differentiate CMT2 from CMT1?
variable onset and demonstrates a greater degree of lower extremity weakness than CMT1
Additional subtypes can include
- optic atrophy
- pyramidal tract involvement
- vocal cord paresis
- hearing impairment
- Adie pupils (tonic pupil, parasympathetic denervation)
- diaphragm involvement
What is Dejerine-Sottas disease?
Previously classified as CMT3, now considered to be a clinical continuum between CMT1 and congential hypomyelinating neuropathy (congenital hypomyelinating neuropathy that presents with severe weakness at birth or within the first month of life)
Autosomal dominant and autosomal recessive inheritance patterns
What is the inheritance pattern of CMT4?
Autosomal recessive inheritance
Is CMT4 primary demyelinating or axonal?
Demyelinating
What characterizes CMT4?
Severe childhood onset weakness and sensory changes
Subtypes can include:
- severe motor delays
- vocal cord paralysis
- glaucoma
What is the second most common type os demyelinating CMT?
X-linked CMT
Both dominantly and recessively inherited X-linked conditions exist
Unique clinical features of X-linked CMT?
similar to CMT1, but men tend to present with more severe disease than women
- cases of associated CNS white matter abnormalities that manifest with ataxia or cognitive abnormalities have been reported
Hereditary neuropathy with pressure palsy (HNPP) is associated with what genetic abnormality?
Reciprocal deletion of PMP-22 gene (CMT1A is associated with duplications in PMP-22)
