Table 1 Clinical and electrophysiological findings of the affected patients from the two families with a Tyr82His mutation in the MPZ gene.
| Age (y) (sex) | Age at onset (y) | Initial symptoms | Weakness/deformity | Sensory signs | Reflexes | NCV motor | NCV sensory | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Median | Ulnar | Peroneal L/R | Median | Ulnar | Sural | |||||||
| H11.05 | 63 (M) | 46 | Back pain | ULd 4 LL 0–3/pes planus | UL+ LL+ * | Areflexia | 34 | 50 | NR/NR | NR | 48 | NR |
| H11.06 | 32 (F) | nr | AS | –/pes cavus | – | Normal | 46 | 50 | 41/31 | 46 | 48 | 37 |
| H11.07 | 26 (F) | nr | AS | – | – | Normal | 55 | 56 | 44/44 | 54 | 55 | 39 |
| H11.08 | 40 (F) | nr | AS | –/pes planus | – | Normal | 55 | 59 | 34/41 | 50 | 53 | 36 |
| H11.09 | 35 (M) | nr | AS | – | – | Normal | 50 | 54 | 38/37 | 47 | 50 | 35 |
| H11.11 | 31 (F) | nr | AS | UL ‐ LLd 4/pes planus | UL ‐ LL + | Reduced ankle | 48 | 48 | 25/28† | 45 | 41 | 32 |
| H11.13 | 73 (M) | 45 | NE | Steppage gait | NE | NE | NE | NE | NE | NE | NE | NE |
| H11.15 | 34 (F) | ? | Legs: S; pain feet | – | – | Normal | NE | 54 | 34/36 | NE | 65 | 39 |
| H11.18 | 43 (F) | 35 | Legs: WD; S | UL ‐ LLd 4 | UL ‐ LL + * | Absent ankle | 50 | 60 | NR/NR | NR | ||
| H11.22 | 51(M) | 45 | Legs: WD; M and S | ULd 4 LL 0–3 | UL ‐ LL + * | Absent ankle | 39 | 48 | ||||
| H11.23 | 53 (F) | ? | Legs: WD | UL 4 LLd 4 | UL ‐ LL + | Absent ankle, knee | 34 | 48 | NE | NE | NE | NE |
| H11.24 | 61 (F) | 55 | Legs: WD; pain | UL ‐ LLd 4/pes planus | UL ‐ LL + * | Absent ankle | 42 | 57 | NE/40† | NE | NE | 51 |
| U1.01 | 44 (F) | 36 | Legs S | –/claw toes | UL ‐ LL + | Reduced ankle | 49 | 57 | 32/34 | NE | 48 | |
| U1.02 | 51 (F) | 47 | Legs S | – | UL ‐ LL + * | Absent ankle, knee | 45 | 52 | 20†/41† | NE | 46 | 55 |
NCV, figures in bold: associated with decreased compound muscle action potential (CMAP) or sensory nerve action potential (SNAP).
†CMAP amplitude <1 mV.
H11.22 (father of H11.11) is included in the table because he was clearly affected and an obligate gene carrier. However, DNA was not available. H11.14, a 64 year old man, also an obligate carrier (father of H11.15), had CMT symptoms from age 45 years, but also a history of alcohol abuse and was therefore excluded. H11.15 complained of pain in her feet and back and altered sensation under her feet, but she had no signs of Charcot‐Marie‐Tooth disease (CMT). Electrophysiological examination showed slightly reduced motor nerve conduction velocities in the legs and a decreased abductor hallucis brevis compound muscle action potential.
Additional family members from whom DNA was not available who are not included in the table: a 66 year old woman (H11.16) with a mainly sensory neuropathy in the legs, who stated that symptoms began after aorto‐iliac segment vascular surgery, and her 40 year old daughter (H11.17) who was asymptomatic but had minor sensory signs in the feet, atrophy of both extensor digitorum brevis muscles and minor electrophysiological abnormalities. H11.25 (father of H11.07 and H11.08) had CMT symptoms starting in the sixth decade, but died from amyotrophic lateral sclerosis. In family U1 the father was believed to be affected as he experienced difficulty walking from the age of 50; a medical record was not available.
AS, asymptomatic; (F), female; L, left; M, motor; (M), male; NE, not examined; R, right; S, sensory; LL, lower limbs; NCV, nerve conduction velocity (for median and ulnar nerve, calculated between elbow and wrist; for peroneal nerve, between fibular head and ankle; for sural nerve, from calf to lateral malleolus); nr, not relevant; NR, no response; UL, upper limbs; WD, walking difficulty; y, years
Motor signs: d, distal; MRC gradings; –, absent.
Sensory signs: *including abnormal pain sensation; +, present; –, absent.