Clinical and genetic summary of congenital insensitivity to pain and erythromelalgia cases
| Case | Onset | Sex | Family history | SCN9A mutation | EMG† | QST‡ for heat pain | Laser doppler tested§ | TST¶ or ARS†† anhidrosis | Nerve biopsy‡‡ |
|---|---|---|---|---|---|---|---|---|---|
| #1 | Infancy | M | No | Nl | >99% | No | Nl | Yes | |
| #2 | Infancy | M | No | Nl | >99% | No | Nl | Yes | |
| #3 | Infancy | F | No | Nl | >99% | No | Nl | Yes | |
| #4 | Infancy | M | No | Nl | >99% | No | Nl | Yes | |
| #5 | Infancy | F | No | Nl | No | No | Nl | Yes | |
| #6 | Infancy | M | No | *R523>X, IVS8-2A>G, K655>R | Nl | No | No | No | Yes |
| Erythromelalgia | |||||||||
| #1 | Twenty | F | Yes | Nl | <1% | Yes | Global | No | |
| #2 | Teens | F | Yes | Nl | >99% | Yes | Nl | No | |
| #3 | Teens | F | No | Nl | <1% | No | Regional | No | |
| #4 | Sixties | F | No | Nl | No | No | No | No | |
| #5 | Teens | F | Yes | Nl | No | Yes | Nl | No | |
| #6 | Teens | F | No | Nl | No | Yes | Regional | Yes | |
| #7 | Thirties | F | Yes | Q10K* | Nl | No | No | No | No |
| #8 | Teens | F | No | Nl | Nl | Yes | Regional | No | |
| #9 | Sixties | F | Yes | Nl | >99% | Yes | Nl | No | |
| #10 | Infancy | M | Yes | Nl | No | Yes | Regional | No | |
| #11 | Forties | F | Yes | Nl | Nl | Yes | Regional | No | |
| #12 | Fifties | F | Yes | Nl | No | Yes | Regional | No | |
| #13 | Teens | F | Yes | Nl | >99% | Yes | Regional | No | |
*Novel mutant variants.
†EMG is electromyography and inclusive of sural and median sensory, peroneal, tibial and ulnar motor nerve conduction studies.
‡QST is quantitative sensory testing that measures heat pain recognition where >95% represents insensitivity and <5% hyperalgesia compared with matched age and gender controls.19
§Erythromelalgia laser Doppler-tested patients who had findings consistent with erythromelalgia by having elevated skin temperature and blood flow at symptomatic distal extremities.2 ,3
¶TST is thermoregulatory sweat test with regions of anhidrosis noted.38
††ARS is autonomic reflex screen with abnormalities limited to sudomotor sweat function loss by quantitative sudomotor reflex testing with regions of anhidrosis noted.38
‡‡All congenital insensitivity to pain patients had whole sural nerve biopsy studied with normal sensory fibre evaluation apart from CIP index case #6 who had skin biopsy nerve studied by PGP9.5 immunostaining.
CIP, congenital insensitivity to pain; Nl, tested and normal; QST, quantitative sensation testing.