Novel nicastrin mutation in hidradenitis suppurativa-Dowling Degos disease clinical phenotype: more than just clinical overlap?

In familial hidradenitis suppurativa (HS), mutations in the genes encoding three subunits of the ‐secretase complex, PSEN1, PSENEN and NCSTN, have pointed to an impaired NOTCH signalling as a pathogenic disease mechanism.1 Dowling Degos Disease (DDD; MIM 179850, 615327, and 615696)―a rare reticulated pigmentary disorder― has also been associated with a deficient NOTCH signalling and patients with mutations in PSENEN suffering from both disorders seem to confirm a potential link between two apparently different conditions.