Preprint identifies KCNA7 as a candidate disease gene for hypokalemic periodic paralysis
A multigenerational family study reports that a missense variant in KCNA7, encoding a voltage-gated potassium channel, co-segregates with recurrent episodes of muscle weakness and low potassium.
Researchers have posted a preprint to bioRxiv describing a new candidate gene for hypokalemic periodic paralysis (HypoPP), a rare inherited skeletal muscle channelopathy characterised by recurrent attacks of muscle weakness accompanying drops in serum potassium. The condition has previously been associated with variants in two ion-channel genes, CACNA1S and SCN4A; this preprint proposes a third.
Studying a multigenerational family, the authors identified a missense variant in KCNA7 — which encodes the Kv1.7 voltage-gated potassium channel — at position c.834A>C (p.Arg278Ser). The variant co-segregated with susceptibility to weakness attacks, serum potassium levels as low as 1.3 mEq/L, and a 40% decrement of the compound muscle action potential following exercise, a physiological signature consistent with HypoPP.
KCNA7 encodes a channel subunit expressed in skeletal muscle, and the authors argue that the affected arginine residue occupies a position consistent with voltage-sensing function. The preprint has not yet undergone peer review, and the findings require independent replication in further families and functional validation before the gene can be considered established in clinical genetics databases. If replicated, KCNA7 would expand the molecular diagnostic range for a condition that currently leaves a proportion of families without a genetic explanation.
Plain-language version
For patients, families, and general readers. Educational only — not medical advice.
Hypokalemic periodic paralysis is a rare inherited muscle condition in which people experience sudden episodes of muscle weakness, often triggered by rest, exercise, or eating carbohydrates. These episodes happen alongside a drop in blood potassium levels. Scientists have known about two genes linked to this condition, but some families have no identifiable fault in either of them.
Researchers studying one large family across several generations have identified a change in a third gene — called KCNA7 — that appeared in all family members affected by the condition but not in unaffected relatives. KCNA7 encodes a protein that helps control electrical signals in muscle cells.
This research is a preprint, which means it has not yet been checked by independent scientific reviewers. Further work is needed to confirm whether KCNA7 is truly a cause of the condition.
This is an educational summary, not medical advice. If anything here raises questions for you, please speak with your GP or a clinical professional.
Sources
Read the original reporting — these are the public sources this summary draws from.
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Primary sourcePreprint bioRxiv (Cold Spring Harbor Laboratory) · 2026-09-14A New Disease Gene for Hypokalemic Periodic Paralysis, KCNA7, Established in a Multigenerational Family