PLCB1 and major depressive disorder: The diagnostic specificity of our findings aligns with studies reporting a PLCB1 gene deletion in 5 out of 15 people with Sz,27 while only occurring in one out of 15 BD patients,28 and in none of the 15 MDD patients examined.29 While there are reports of other PLC isoforms being associated with BD pathogenesis and treatment response,30, 31 our findings are consistent with PLCB1 being not highly implicated in affective disorders.27