If a deletion is the easiest way to lose a functional TP53 copy, but a second deletion poses a problem because it normally also entails bi-allelic loss of other genes that might be important for MM cell fitness (but which are not necessarily related to malignancy), then the second event is most likely a precise hit to TP53, i.e. an inactivating mutation. Here, TP53 is linked to Miyoshi myopathy.