ClinGenAR Get External Records

Get detailed cross-references and external database records for a ClinGen canonical allele. Takes a ClinGen allele ID (CA ID) and returns links to ClinVar, dbSNP, COSMIC, gnomAD, ExAC, and other databases. Useful for finding all known database entries for a given variant. Example: CA000387 (TP53 R248Q) returns ClinVar variation IDs, COSMIC IDs, dbSNP rsIDs, and gnomAD allele frequencies.