CTNNA1 Familial Expansion Study

Inclusion Criteria: * 18 years of age and older * Participants must be carrier, or a first degree relative of a carrier, of a CTNNA1 loss-of-function variant defined as: a variant predicted to lead to protein truncation (nonsense and frameshift variants), a large deletion of one or more exons, or a consensus splice site variant predicted to disrupt splicing in CTNNA1. CTNNA1 loss-of-function variants do not need to be classified as pathogenic or likely pathogenic to be included. * Participants must be able to understand and read English * Participants must be able to provide informed verbal or written consent Exclusion Criteria: * Less than 18 years of age * Individuals who do not carry a CTNNA1 loss-of-function variant and are not a first degree relative of a CTNNA1 loss-of-function variant carrier. * Individuals who cannot speak and read English * Major psychiatric illness or cognitive impairment that in the judgement of the study investigators or study staff would preclude study participation * Unable to comply with the study procedures as determined by the study investigators or study staff