Phenotypic expansion of CACNA1C-associated disorders to include isolated neurological manifestations

March 8, 2026
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AUTHORS

Lance H Rodan, Rebecca C Spillmann, Harley T Kurata, Shawn M Lamothe, Jasmine Maghera, Rami Abou Jamra, Anna Alkelai, Stylianos E Antonarakis, Isis Atallah, Omer Bar-Yosef, Frédéric Bilan, Kathrine Bjorgo, Xavier Blanc, Patrick Van Bogaert, Yoav Bolkier, Lindsay C Burrage, Björn U Christ, Jorge L Granadillo, Patricia Dickson, Kirsten A Donald, Christèle Dubourg, Aviva Eliyahu, Lisa Emrick, Kendra Engleman, Michaela Veronika Gonfiantini, Jean-Marc Good, Judith Kalser, Chiara Kloeckner, Guus Lachmeijer, Marina Macchiaiolo, Francesco Nicita, Sylvie Odent, Emily O’Heir, Xilma Ortiz-Gonzalez, Marta Pacio-Miguez, María Palomares-Bralo, Loren Pena, Konrad Platzer, Mathieu Quinodoz, Emmanuelle Ranza, Jill A Rosenfeld, Eliane Roulet-Perez, Avni Santani, Fernando Santos-Simarro, Ben Pode-Shakked, Cara Skraban, Rachel Slaugh, Andrea Superti-Furga, Isabelle Thiffault, Richard H van Jaabrsveld, Marie Vincent, Hong-Gang Wang, Pia Zacher, Undiagnosed Diseases Network, Eric Rush, Geoffrey S Pitt, Ping Yee Billie Au, Vandana Shashi

Genet Med. 2021 Oct;23(10):1922-1932. doi: 10.1038/s41436-021-01232-8. Epub 2021 Jun 23.

ABSTRACT

PURPOSE: CACNA1C encodes the alpha-1-subunit of a voltage-dependent L-type calcium channel expressed in human heart and brain. Heterozygous variants in CACNA1C have previously been reported in association with Timothy syndrome and long QT syndrome. Several case reports have suggested that CACNA1C variation may also be associated with a primarily neurological phenotype.

METHODS: We describe 25 individuals from 22 families with heterozygous variants in CACNA1C, who present with predominantly neurological manifestations.

RESULTS: Fourteen individuals have de novo, nontruncating variants and present variably with developmental delays, intellectual disability, autism, hypotonia, ataxia, and epilepsy. Functional studies of a subgroup of missense variants via patch clamp experiments demonstrated differential effects on channel function in vitro, including loss of function (p.Leu1408Val), neutral effect (p.Leu614Arg), and gain of function (p.Leu657Phe, p.Leu614Pro). The remaining 11 individuals from eight families have truncating variants in CACNA1C. The majority of these individuals have expressive language deficits, and half have autism.

CONCLUSION: We expand the phenotype associated with CACNA1C variants to include neurodevelopmental abnormalities and epilepsy, in the absence of classic features of Timothy syndrome or long QT syndrome.

PMID:34163037 | PMC:PMC8488020 | DOI:10.1038/s41436-021-01232-8

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