POLR1C and Alzheimer disease: The predominant gene involved is TCOF1, with additional contributions from POLR1B, POLR1C, and POLR1D. These genes exhibit distinct inheritance patterns: TCOF1 and POLR1B variants are autosomal dominant, POLR1C variants are autosomal recessive, and POLR1D variants can be either autosomal dominant (AD) or recessive (3).