logo Genetic diseases

Systemic dermatology

Miscellaneous genetic diseases


  • Recognise cutaneous signs of neurofibromatosis, tuberous sclerosis and pseudoxanthoma elasticum.


Cutaneous signs of type 1 neurofibromatosis include:

Café au lait macule


Plexiform neurofibroma

Axillary freckling

Skin tags

Tuberous sclerosis

Tuberous sclerosis, also known as epiloia, is an autosomal dominant genetic neurodermatosis that presents with epilepsy, mental retardation and cutaneous signs. These include:


ash-leaf macule

periungual fibroma

Pseudoxanthoma elasticum

Pseudoxanthoma elasticum (PXE) is a group of inherited disorders in which elastic tissue in skin, blood vessels and eyes is defective. The result is groups of yellowish bumps on the neck, axillae and elsewhere associated with gastrointestinal haemorrhage, hypertension, peripheral vascular disease and ocular “angioid” streaks and retinal haemorrhages.