[Monilethrix is a hereditary hair shaft disorder].

Monilethrix is a rare genodermatosis with high penetrance and variable expressivity. This is a case report of a Danish family with varying phenotypical presentations. The family members were diagnosed using dermatoscopy and microscopy, which were subsequently supported by gene sequence analysis. No cure of monilethrix exists, but a single case report shows promising results using low dosage of oral minoxidil. Reducing hair dressing trauma to diminish weathering remains the best prophylaxis.