The following is a summary of the current understanding of the genetic types of CMT.
The key point to remember is that there are two main forms of CMT:
Demyelinating (CMT1) – affects the myelin sheath insulating & nourishing the nerve’s axon.
Axonal (CMT2) – directly affects the axon.
The rest of the various classifications are all variations of these two main groups and, currently, will have no impact on the management of the condition.
CLINICAL TYPE | INHERITANCE | LOCUS/GENE |
Demyelinating (CMT 1) | ||
CMT 1A | AD | Duplication 17p11.2-12 / PMP-22 17p11.2-12 / Point mutation PMP-22 |
CMT 1B | AD | 1q22-q23 / Point mutation Po |
CMT 1C | AD | 16p13.1 - p12.3 / SIMPLE / LITAF |
CMT 1D | AD | 10q21-q22 / Point mutation EGR2 |
Charcot-Marie-Tooth type 1 x-linked (CMT X) | ||
CMT X | X-linked | Xq13.1 / Point mutation Cx32 |
Dejerine-Sottas disease (HMSN III) | ||
DSD A | AD (AR) | 17p11.2-12 / Point mutation PMP-22 |
DSD B | AD (AR) | 1q22-q23 / Point mutation Po |
DSD C | AD | 10q21-q22 / Point mutation EGR2 |
Congenital hypomyelinating neuropathy (CHN) | ||
CHN A | AD | 17p11.2-12 / Point mutation PMP-22 |
CHN B | AD | 1q22-q23 / Point mutation Po |
CHN C | AD (AD) | 10q21-q22 / Point mutation EGR |
Hereditary neuropathy with liability to pressure palsies (HNPP) | ||
HNPP A | AD | Deletion 17p11.2 / PMP-22 17p11.2-12 / Point mutation PMP-22 |
Charcot-Marie-Tooth type 1 autosomal recessive (CMT1-AR) | ||
CMT1 ARA (CMT 4A) | AR | 8q13 - 21.1/ GDAP1 |
CMT1 ARB1 (CMT4B1) | AR | 11q22 / MTMR2 |
CMT1 ARB2 (CMT4B2) | AR | 11p15 / MTMR13 |
CMT1 ARC (CMT4C) | AR | 5q23-q33 / KIAA1985 |
CMT1 ARD (CMT4D / HMSNL) | AR | 8q24 / NDRG1 |
CMT1 ARE (CMTDN) | AR | 18q |
CMT1 ARF (CMT4F) | AR | 19q13.1-13.3 / Periaxin |
CMT1 ARG (HMSNR) | AR | 10q22-q |
Axonal (CMT 2) Charcot-Marie-Tooth type 2 autosomal dominant (CMT2 / HMSN II) | ||
CMT 2A | AD | 1p35-KIF1B / GTPase mitofusin 2 |
CMT 2B | AD | 3q13 – q22 / RAB7 |
CMT 2C | AD | 12q23 – q24 |
CMT 2D | AD | 7p14 / GARS |
CMT 2E | AD | 8p21 / NF-L |
CMT 2F | AD | 7q11-q21 / HSP 27 |
CMT 2G | AD | 12q12-q13.3 |
CMT 2L | AD | 12q24 / HSP 22 |
CMT 2 | AD | 1q22-q23 / Point mutation Po |
CMT 2 (HMSNP) | AD | 3q13.1 |
Charcot-Marie-Tooth type 2 x-linked (CMT 2X) | ||
CMT 2X | X-linked | Xq24 – q26 |
Charcot-Marie-Tooth type 2 autosomal recessive (CMT2 AR) | ||
CMT2 AR | AR | 1q21.2 – 21.3 / LMNA |
CMT2 AR | AR | 19q13.1 |
CMT2 AR | AR | 8q21 / GDAP1 3. |
Dominant Intermediate CMT (DI-CMT) | ||
DI-CMTA | AD | 10q24.1-q25.1 |
DI-CMTB | AD | Dynamin 2 |
DI-CMTC | AD | 1p34-p35 |
AD - autosomal dominant
AR - autosomal recessive
Page Last Updated 17 November 2009
