Table 1.

Genetic syndromes associated with NMSC.

Syndrome	Type of NMSC	Clinical Features
Xeroderma Pigmentosus	BCC SCC	Autosomal recessive disorder characterized by defects in the mechanisms of DNA repair. NMSCs are frequently developed by younger (≤20 years). The risk is directly associated to UVR exposition.
Oculocutaneous Albinism	SCC	Autosomal recessive disease showing a pigmentary dilution of the skin, eyes, and hair. SCCs are frequently developed by young subjects exposed to UVR. A high incidence of metastatic SCC has been described in black population.
Epidermodysplasia Verruciformis	SCC	Rare and usually recessively inherited disorder characterized by a colonization of the skin by HPV. The majority of patients develop NMSC as adults, usually in sun-exposed regions, but earlier with respect to the general population. Aggressive biological behavior includes perineural spread, metastases and death.
Dystrophic epidermolysis bullosa	SCC	It is characterized by both dominant and recessive mutations of the type VII collagen gene. The majority of recessive patients develop SCCs, that occur during the third-fifth decade of life, frequently multiple and with high attitude to local recurrence and spreading to distant metastatic sites.
Basal Cell Nevous Syndrome (Gorlin)	BCC	It is an autosomal dominant disorder caused by inactivating mutations of PTCH1 or rarely PTCH2. Clinical features include early NMSC, involvement of multiple sites on course of life, odontogenic keratocysts of the jaw, palmo-plantar pits calcifications of the falx cerebri and abnormalities of the skeleton. Patients also develop multiple cancers of the SNC, ovary and heart, as well as other skin defects such as epidermoid cysts and facial milia.
Bazex-Dupré-Christol Syndrome	BCC	It is a rare condition characterized by follicular atrophoderma of the hands and feet, hypotrichosis, localized hypohidrosis, epidermoid cysts and multiple BCCs developed during the second decade of lifer showing a trichoepithelioma-like histology. The inheritance pattern is often X-linked.
Rombo Syndrome	BCC	Patients have an atrophoderma vermiculatum-like appearance on the cheeks with evidence of sweat duct proliferation. They often suffer of hypotrichosis, blepharitis, peripheral erythema, trichoepithelioma and skin cancer.