The 52 variants of CMT… and their practical checklists

Jean-Marie Charcot, Pierre Marie, and Howard Henry Tooth will be confounded to see what has become of the disease they described hundreds of years ago. Charcot-Marie Tooth disease (CMT) was a simple and straightforward disease then, with easily recognisable features such as the ‘classic’ high arched foot (pes cavus), the hammer toes, and the inverted champagne glass appearance of the leg.

By Benefros at English WikipediaOwn work (Original text: Own work, originally from en.wikipedia; description page is/was here.), CC BY-SA 3.0, Link

What was once a clear clinical entity has however morphed into a complex genetic maze. CMT has literally evolved into a hydra with 52 genetically distinct heads (and I thought I will never use literally in this blog). Half of this number is made up by the 26 forms of CMT type 2, which now runs from CMT2A to CMT2Z! Where to go after Z is anyones guess?

CC BY 2.0, Link

What neurologists could easily recognise and classify by distinctive clinical features now runs rings around them with complex neurophysiological cut-off points.

By JanbroggerOwn work, Public Domain, Link

In tackling the increasingly complex phenomenon of CMT, Neurochecklists has attempted to demystify the disease with a variety of simple checklists such as:

The genetic classification of CMT

The distinctive features of CMT

The differentiating features of CMT

The investigations of CMT

The management of CMT

Or you may wish to dive in properly and explore individual CMT subtypes. In which case, here are the 52 varieties of CMT and their genetic mutations, all linked to their checklists. Watch out for SPG11!

CMT1: Autosomal dominant demyelinating

CMT1A: PMP22 

CMT1B: MPZ

CMT1C: LITAF/SIMPLE 

CMT1D: EGR2 

CMT1E: PMP22 

CMT1F: NEFL 

CMT2: Autosomal dominant axonal

CMT2A: MFN2  

CMT2B: RAB7 

CMT2C: TRPV4

CMT2D: GARS 

CMT2E: NEFL 

CMT2F: HSPB1 

CMT2G (old term for CMT2P)

CMT2H: GDAP1 

CMT2I: MPZ 

CMT2J: MPZ 

CMT2K: GDAP1 and JPH1 

CMT2L: HSPB8 

CMT2M: DNM2 

CMT2N: AARS 

CMT20: DYNC1H1 

CMT2P: LRSAM1 

CMT2Q: DHTKD1 

CMT2R: TRIM2 

CMT2S: IGHMBP2 

CMT2T: MME 

CMT2U: MARS 

CMT2V: NAGLU 

CMT2W: HARS 

CMT2X: SPG11

CMT2Y: VCP 

CMT2Z: MORC2

CMT2B1 and CMT2B2: Autosomal recessive axonal

CMT2B1: LMNA

CMT2B2: MED25 

CMT4: Autosomal recessive demyelinating

CMT4A: GDAP1 

CMT4B1: MTMR2 

CMT4B2: SBF2 

CMT4B3: SBF1 

CMT4C: SH3TC2

CMT4D: NDRG1 

CMT4E: MPZ and EGR2

CMT4F: PRX 

CMT4G: HK1 

CMT4H: FGD4 

CMT4I (non-existent)

CMT4J: FIG4 

CMT3,5 and 6

CMT3: PMP22, MPZ, EGR2, PXN, GJB1

CMT5: MFN2

CMT6: MFN2

CMTX: X-linked

CMTX1: JGB1 

CMTX2: mutation unknown

CMTX3: BSCL2

CMTX4: AIFM1 

CMTX5: PRPS1

CMTX6: PDK3 

CMTDI: Autosomal dominant intermediate

CMTDIA: mutation unknown

CMTDIB: DNM2

CMTDIC: YARS 

CMTDID: MPZ 

CMTDIE: INF2 

CMTDIF: GNB4 

CMTRI: Autosomal recessive intermediate

CMT2RIA: GDAP 

CMT2RIB: KARS

CMT2RIC: PLEKHG5 

CMT2RID: COX6A1 

 

Explore these and more on Neurochecklists

 

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