ACTN1 and Alzheimer disease: Unexpectedly, two semen donors were found to harbor autosomal dominant (AD) mutations, which were consistent in both sperm and blood samples, one donor had a likely pathogenic (LP) mutation in the TPM2 gene (NM_003289.3: c.564-1G > A), potentially causing distal arthrogryposis (MIM #108120) or nemaline myopathy 4 (MIM #609285); and the other with ACTN1 (NM_001102.4: c.1348C > T, LP), which would cause bleeding disorder (platelet-type, MIM #615193).