Table 1.
Motor nerve conduction studies of four patients in the study.
| Patient | ||||||||||||||||||
| BAB392 | BAB1219 | BAB1415 | BAB3724a | BAB7807 | Normal values | |||||||||||||
|
Age at testing (years) |
4 | 35 | 3.5 | 30 | 24 | |||||||||||||
|
Age of onset (years) |
3–4 | Childhood | 2–3 | 3 | 23 | |||||||||||||
| Family history | Negative | Negative | Negative | Negative | Negative | |||||||||||||
| Motor NCS |
DL (ms) |
V (m/s) |
Amp (mV) |
DL (ms) |
V (m/s) |
Amp (mV) |
DL (ms) |
V (m/s) |
Amp (mV) |
DL (ms) |
V (m/s) |
Amp (mV) |
DL (ms) |
V (m/s) |
Amp (mV) |
DL (ms) |
V (m/s) |
Amp (mV) |
| R. median | 3.1 | 44 | 2.5 | 8.9 | 23.3 | 8.51 | 2.5 | 39 | N/A | NR | NR | NR | N/A | 41.4 | N/A | <4.0 | >50 | 5.0 |
| R. ulnar | 3.0 | 42 | 2.5 | 5.3 | 29.9 | 7.57 | 1.8 | 67 | >4 | NR | NR | NR | N/A | N/A | N/A | <3.5 | >50 | 5.0 |
| R. common peroneal |
4.9 | 28 | 0.75 | NR | NR | NR | NR | NR | NR | NR | NR | NR | N/A | 22.3 | N/A | <4.5 | >40 | 2.0 |
| R. tibialis | 4.8 | 22 | 1.5 | NR | NR | NR | NR | NR | NR | NR | NR | NR | N/A | 29.2 | N/A | <5.0 | >40 | 4.0 |
| Clinical diagnosis |
CMT; Tonic-clonic seizures; developmental delay |
CMT1 | CMT1 | CMT; sensorineural hearing loss; glaucoma |
CMT | |||||||||||||
| CNV |
PRICKLE1 deletion (de novo) |
MPZ duplication | KIF24 deletion |
NDRG1 duplicationa |
MPZ first exon deletion |
|||||||||||||
| SNV |
Chr1:12059066 G>T; MFN2 p.V244L; de novo |
Chr14:105180633 G>A; INF2 p.R1045Q |
Chr1:12059082 C>T; MFN2 p.S249F |
Chr14:102481630 A>C; DYNC1H1 p.K2401N |
N/A | |||||||||||||
Boldface type indicates likely pathogenic mutations.
Amp, amplitude; CMT, Charcot-Marie-Tooth; CNV, copy-number variant; DL, distal latency; NCS, nerve conduction studies; N/A, not available; NR, not recordable; R., right; SNV, single-nucleotide variant; V, conduction velocity.
a
Previously published NDRG1 CNV is homozygous and is a known recessive locus. All others are heterozygous and have known or postulated autosomal dominant mechanisms.