[Syndromes with skin fragility].

Syndromic disorders with skin fragility belong to different groups of genodermatoses: epidermolysis bullosa (EB), Ehlers-Danlos syndrome and porphyria. The genetic defects mainly concern structural proteins which assure the mechanical stability of the skin and other tissues. Depending on the expression pattern of the affected protein in the skin, cutaneous fragility may manifest as superficial erosions, blisters, wounds, wound healing defects or scars. Extracutaneous manifestations are manifold and involve the heart, skeletal muscles, intestine, kidneys, blood vessels or the skeleton. Syndromic types of EB include in addition to skin blistering: (i) cardiomyopathy in case of desmoplakin, plakoglobin, or kelch-like protein mutations; (ii) muscular dystrophy in case of plektin mutations; (iii) pyloric atresia in case of integrin α6β4 or plectin mutations; (iv) nephrotic syndrome in case of CD151 or integrin α3 mutations. Lysyl hydroxylase 3 mutations affect posttranslational modifications of collagens and lead to a dystrophic epidermolysis bullosa-like multisystemic disorder. Ehlers-Danlos syndromes are due to defects of dermal collagens or their processing and affect the skin, joints and blood vessels. Finally porphyrias are complex metabolic disorders with photosensitivity and sometimes skin fragility, liver or neurologic problems. Their pathogenesis relies on the accumulation of precursors in the tissues. Although these syndromes are rare in clinical practice, knowledge of the syndromic constellation contributes to early diagnosis and detection of complications.