Periodic paralysis mutation MiRP2-R83H in controls: Interpretations and general recommendation
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Updated: Aug 25, 2026
Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease
Published on: April 4, 2018
Karin Jurkat-Rott1, Frank Lehmann-Horn
1Department of Applied Physiology, Ulm University, Germany.
Abstract:
An R83H point mutation in KCNE3-encoded MiRP2 has been reported to cause 2% of all cases of familial periodic paralysis. The authors found MiRP2-R83H in 3 of 321 control subjects and in 5 unaffected related individuals. Provocation of an unaffected carrier with glucose or KCl did not induce weakness. The authors propose that causality criteria for mutations require exclusion of mutations in n = ln(P)/ln(1 - p(1)) ethnically matched control chromosomes (P = acceptable error probability; p(1) = mutation prevalence in patient chromosomes).
Insights
A mutation linked to familial periodic paralysis was found in healthy individuals, suggesting it may not be the sole cause. Further genetic analysis is needed to confirm mutation causality in disease.
Area of Science:
- Genetics
- Neurology
- Molecular Biology
Background:
- Familial periodic paralysis is a group of genetic disorders affecting muscle function.
- A specific mutation, R83H in KCNE3-encoded MiRP2, has been implicated in causing familial periodic paralysis.
- The prevalence of this mutation in control populations requires further investigation.
Purpose of the Study:
- To investigate the presence of the MiRP2-R83H mutation in control subjects.
- To evaluate the penetrance of the MiRP2-R83H mutation in unaffected carriers.
- To propose refined criteria for establishing mutation causality in genetic diseases.
Main Methods:
- Genetic screening of familial periodic paralysis patients and ethnically matched control subjects.
- Phenotypic assessment of unaffected carriers, including provocative testing (glucose, KCl).
- Statistical analysis to assess mutation prevalence and propose causality criteria.
Main Results:
- The MiRP2-R83H mutation was identified in 3 of 321 control subjects.
- The mutation was also found in 5 unaffected individuals from affected families.
- Provocation tests in an unaffected carrier did not elicit muscle weakness.
Conclusions:
- The MiRP2-R83H mutation may not be fully penetrant or causative in all cases of familial periodic paralysis.
- The presence of the mutation in controls suggests a need for re-evaluation of its role.
- Stricter criteria, including exclusion of mutations in ethnically matched controls, are proposed for establishing genetic causality.
