Dynamic clamps and methods of use thereof

Inventors

Petrou, Steven

Assignees

Rogcon UR Inc • Praxis Precision Medicines Inc

Abstract

The present invention provides methods for determining the phenotype (e.g., gain-of-function or loss-of-function) of a mutation in an ion channel or receptor by using a dynamic voltage clamp. The invention also features methods of determining whether a mutation is a gain-of-function or loss-of-function mutation and treating a disease or disorder associated with the particular gain-of-function or loss-of-function mutation.

Core Innovation

The invention provides a method of determining whether a mutation in an ion channel or a receptor is a gain-of-function mutation or a loss-of-function mutation using dynamic clamp. A dynamic clamp is provided in electrical contact with a biological cell or a portion thereof that comprises a mutant ion channel or receptor, to provide a waveform. The dynamic clamp applies a signal based on modulation of the mutant ion channel in the biological cell or portion thereof, thereby providing the waveform at the biological cell or portion thereof.

The method includes detecting modulation of the waveform at the biological cell or portion thereof, where modulation of the waveform is determined relative to a control. The classification is defined by the direction of the change compared to the control, where increased modulation compared to the control indicates a gain-of-function mutation and decreased modulation compared to the control indicates a loss-of-function mutation.

The described approach supports dynamic clamp implementations that include waveform generation and measurement associated with action potential firing and a dynamic action potential clamp that couples an electrophysiology-based cellular context with a real-time simulator via a feedback loop. The document further describes optional comparison or subtraction of specific channel contributions while supporting both voltage-clamp and current-clamp implementations, including voltage signal and current signal relationships used for detecting waveform modulation.

Claims Coverage

The independent claim sets out one core inventive method with three key decision points: dynamic clamp application to a mutant channel or receptor waveform, detection of waveform modulation relative to a control, and classification of the mutation based on increased versus decreased modulation. Dependent claims refine the independent claim by defining the control as wild-type channel or receptor, narrowing the waveform to action potentials, specifying voltage-signal and current-signal measurement relationships, restricting the ion channel classes, and further narrowing sodium-channel subtypes.

Overall claim coverage centers on using dynamic clamp to apply signals that modulate a mutant ion channel or receptor to produce a waveform, measuring whether waveform modulation increases or decreases relative to a control, and classifying the mutation as gain-of-function or loss-of-function. Dependent claims further specify control as wild-type, waveform as an action potential, the voltage/current measurement pairing for detecting modulation, and restrictions on the ion channel classes and sodium-channel subtypes.

Stated Advantages

Documented Applications