Laboratory Test Information Guide

Details for Paramyotonia Congenita Hyperkalemic Periodic Paralysis

Test Name: Paramyotonia Congenita Hyperkalemic Periodic Paralysis
Alternate Name(s): Hyperkalemic Periodic Paralysis Type 1
PMC
Laboratory: Molecular Diagnostics
Specimen Type: Whole blood-1 x 4 mL Lavender EDTA top Vacutainer tube
Collection Information: Blood samples must be maintained at room temperature.
Requisition: MOLECULAR DIAGNOSTIC REQUISITION
Test Schedule: As required
Monday - Friday
0800 - 1600h
Turnaround time from when specimen
is received in testing laboratory:
 
Routine
4 weeks
Stat
 
 
Reference Range: See report
Effective Date:  
Revised Date: 2016-03-21
Critical Value: N/A
Interpretive Comments: Paramyotonia congenita (PMC) of Von Eulenburg is an autosomal dominant muscular disease characterized by exercise and cold-induced myotonia and weakness. A number of missense mutations1,2 in the alpha-subunit of the adult skeletal muscle voltage-gated sodium channel (SCN4A) gene have been identified to cause a spectrum of muscular diseases. These include PMC of Von Eulenburg, PMC without cold paralysis, potassium-aggravating myotonia, and hyperkalemic periodic paralysis (HyperPP). Varying degrees of overlap of the clinical symptoms of PMC and HPP have been recognized, and HyperPP/PMC has been reported in association with eight mutations in the SCN4A gene3.
(EX13:I693T, EX13:T704M, EX19:A1156T, EX22:T1313M, EX23:M1360V, EX23:M1370V, EX24:R1448C, EX24:M1592V).

References

1. Moran. O et al. (1998) J Bioenerg Biomember December 30;(6):579-88
2. Yang et al. (1994) Proc Natl Acad Sci USA December 20; 91(26):12785-9
3. Brancati et al. (2003) J Neurol Neurosurg Psychiatry. 74:1339-41
4. Karin Jurkat-Rott, (2003) Gene reviews:
http://www.genetests.org
5. http://blocks.fhcrc.org/sift/SIFT.html

*cDNA seq. of SCN4A gene as in gb Accession #NM_000334. Numbered according to HGVS nomenclature as in den Dunnen et al Hum Genet (2001) 109:121-124. intial coding ATG=1
Special Processing:  
Comments: For more information click on:

Molecular Diagnostic Laboratory
Method of Analysis: DNA Sequence Analysis
Critical Information Required:  
Storage & Shipment: Must be received in testing laboratory within 5 days of collection, shipped at room temperature by courier/overnight delivery.
System Codes: 
Cerner
 
 
Referred To:  

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