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