Table 1. Summary of the CNS clinical phenotypes of patients with mutations studied in this communication.
| Mutant | Trigger | Clinical | References |
|---|---|---|---|
| F51L | Returning from high altitude | ADEM-like illness, with MRI changes and full recovery. | Scherer, unpublished |
| T55I | None noted | Two brothers with transient CNS generalized weakness, dysarthria, dysphagia, and MRI changes. An unrelated 63 yo patient had an abnormal MRI. | 15,16 |
| R75W | 4 unprovoked; worst attack after wrestling | Two sets of attacks − 3 closely-spaced attacks at 12 yo; one unprovoked attack followed by one provoked attack at 15 yo, with MRI changes. | 19 |
| E102del | Mother – infections, Son 1 - exercise, and after return from mountains, Son 2 - infection surgery | Mother’s symptoms recurred at irregular intervals. Son 1: tetraparesis for 1 hour after football practice; confusion, weakness for 3 hours, weeks after being at high altitude. Son 2: multiple brief, 1 hour episodes during childhood. One severe episode at 19 yo, following appendectomy in setting of mononucleosis. Both showed MRI WM changes. | 20 |
| V139M | Fever, Trauma?, Infection? | Yearly < 1 hour episodes after fever. Longer, 12 hour episode at age 17 with relapse on day 2. 2 brothers: 13 yo with 1/2 day episode 2 weeks after concussion with relapse a day later; 16 yo with hemiparesis and WM changes on MRI, 2 weeks after pneumonia. | 29,22 |
| R142Q | Transient neurological findings and WM changes on MRI. Associated with deafness. | S. Yum PC60 | |
| R142W | Return from high altitudes | 26 yo with subacute dysarthria, incoordination, difficulty walking, and a feeling of weakness within days of returning from alt of 8000 ft. lasting 2 weeks but waxing and waning. 41 yo female patient with WM changes on MRI. | 17,13 |
| R164Q | Fever, Post influenza infection? | 14 yo with 3 days paresthesia, disorientation, ataxia and weakness and foci of WM changes on MRI. | 26 |
| R164W | Fever?None noted | 14 yo with 6 hours of headache, nausea, vertigo, and fever. bilateral facial weakness, dysarthria, dysphagia, pyramidal right-sided weakness. 44 yo man with 10 y of CNS symptoms; normal VERs, abnormal BAERs, MRI findings; no clinical event for CNS involvement. 13 yo with 30 minutes of slurred speech and leg weakness followed a week later by 36 hours of right hemiparesis and dysphasia and diffuse WM changes on MRI. | 18,21,30 |
| C168Y | return from high altitudes | 16 yo with 5 days of multiple 8-10 hr episodes with tingling in the fingers of both hands and the perioral region, progressing to severe dysarthria, weakness, and ataxia and WM changes on MRI. | 17 |
| V177A | 7 yo with 36 hours of left hemiparesis and dysphasia. | 24 | |
| Y151C | PNS-only; no evoked potential abnormalities. | ref. 31 and PC G. Nicholson | |
| V181M | PNS-only; no evoked potential abnormalities. | ref. 31 and PC G. Nicholson | |
| R183C | PNS-only; no evoked potential abnormalities. | ref. 31 and PC G. Nicholson | |
| L239I | PNS-only; no evoked potential abnormalities. | ref. 31 and PC G. Nicholson |
WM: white matter; yo: year old; ADEM: acute disseminated encephalomyelitis; PC: personal communication.