CRISPR/Cas9 genome editing technology was used to generate a nine-base deletion adjacent to the initial IZUMO1_v1 methionine start codon ( IZUMO1_v1 (p.Met1del) / IZUMO1_v2 (p.Ala30-Met32del). A reduced amount of encoded protein is expressed via an alternative splice codon (IZUMO1_v2). (J:275429)