Many of the disease-causing point mutations occur within structure-lacking intrinsically disordered regions (IDRs) of proteins. IDRs often contain short linear motifs (SLiMs) that are crucial for protein-protein interactions (PPIs) and are often subject to phosphorylation. Our approach involved immobilizing synthetic peptides representing mutated phosphorylation sites within the IDR regions onto cellulose membranes to capture interacting proteins from cellular extracts. This enabled simultaneous comparison of interaction partners between wild-type, phosphorylated, and mutated peptide forms, allowing functional assessment of individual mutations. We screened 36 disease-causing phosphorylation site mutations within IDRs, sourced from PTMVar database. The results revealed substantial differences between phosphorylated and mutated peptide interactomes, often due to disrupted phosphorylated SLiMs