A genodermal disease that can cause skin malignancy are –
Xeroderma pigmentosa is a genodemaatosis which can cause skin malignancy.
Neurofibromatosis (a genodermatosis) also predisposes to malignancy, but it is extra-cutaneous malignancy (not skin malignancy).
Xeroderma pigmentosa
Neurofibromatosis
Actinic keratosis
Porphyria cutanea tarda