Familial episodic ataxia
From Ganfyd
Web Resources for Familial episodic ataxia
Genetic Databases
Relevant Clinical Literature
UK Guidance
Other Wikis
Medpedia on Familial episodic ataxia (Less technical, good quality control)
Wikipedia on Familial episodic ataxia (Less technical, ? quality control)
- Episodic ataxia type 1 due to mutations of KCNA1 at 12p13 coding for potassium channel protein potassium voltage-gated channel subfamily A member 1
- Continuous muscle movement (myokymia, neuromyotonia)
- Periodic ataxia which can be precipitated by:
- Postural change
- Emotion
- Caloric-vestibular stimulation
- No nystagmus
- Can respond to phenytoin
- Association with autosomal dominant hypomagnesemia
- Episodic ataxia type 2 (acetazolamide-responsive hereditary paroxysmal cerebellar ataxia) due to mutations and harder to detect deletions and duplications of CACNA1A at 19p13 coding for voltage-dependent P/Q-type calcium channel subunit alpha-1A[1].
- Acetazolamide-responsive attacks of ataxia
- Migraine (close association with familial hemiplegic migraine type 1)
- Nystagmus - present between episodes
- Cerebellar atrophy
- Some patients respond to the potassium channel blocker 4-aminopyridine[2].
- Episodic ataxia type 3 maps to 1q42
- Autosomal dominant
- Vestibular ataxia
- Vertigo
- Tinnitus
- Interictal myokymia
- No nystagmus
- Response to acetazolamide
- Episodic ataxia type 4 (periodic vestibulocerebellar ataxia, PATX)
- Episodic ataxia type 5 - due to mutations of CACNB4 at 2q22 coding for voltage-dependent L-type calcium channel subunit beta-4
- Vertigo
- Ataxia lasting hours
- Interictal nystagmus, dysarthria and truncal ataxia
- Response to acetazolamide
- Mutations of same gene cause epilepsy
- Episodic ataxia type 6 - SLC1A3 at 5p13 coding for excitatory amino acid transporter 1 (GLAST-1)
- Ataxia associated with emotions, fatigue, alcohol and caffeine
- Worse with age
- Hemiplegic migraine association wity more severe forms
- Acetazolamide response
- Episodic ataxia type 7 - 19q13
- Autosomal dominant
- Onset before 20 years
- Attacks hours to days with weakness and dysarthria
- Associated with exercise and emotions
- Vertigo possible
- Attacks settle with age
References
- ↑ Labrum RW, Rajakulendran S, Graves TD, Eunson LH, Bevan R, Sweeney MG, Hammans SR, Tubridy N, Britton T, Carr LJ, Ostergaard JR, Kennedy CR, Al-Memar A, Kullmann DM, Schorge S, Temple K, Davis MB, Hanna MG. Large-scale calcium channel gene rearrangements in Episodic Ataxia and Hemiplegic Migraine: Implications for diagnostic testing. Journal of medical genetics. 2009 Jul 7.(Epub ahead of print) (Link to article – subscription may be required.)
- ↑ Strupp M, Kalla R, Dichgans M, Freilinger T, Glasauer S, Brandt T. Treatment of episodic ataxia type 2 with the potassium channel blocker 4-aminopyridine. Neurology. 2004 May 11; 62(9):1623-5.
