Cav1.3 L-type calcium channels, encoded by the gene CACNA1D, translate electrical signals at the cell membrane into changes in intracellular calcium. Through this fundamental role, they regulate the activity of many different cell types in the brain and endocrine system.

Disease-causing variants in CACNA1D can alter how Cav1.3 channels open and close. Importantly, they do not all affect channel function in the same way. Instead, each variant produces a distinct biophysical fingerprint, often combining activity-enhancing and activity-reducing changes in channel gating. How this fingerprint translates into cellular dysfunction depends strongly on the cellular environment. Different variants may therefore converge on similar functional changes in a particular cell type, while the very same variant can have strikingly different consequences across cell populations, depending on features such as resting membrane potential, electrical activity patterns, calcium buffering and the expression of other ion channels. This complex interplay may help explain the broad and variable spectrum of neurological and endocrine symptoms observed in individuals with CACNA1D-related disorders.