In this issue, Wilson et al. report the first case of homozygous dominant negative mutations in KRT17 in pachyonychia congenita (PC). Homozygous dominant negative mutations are a rare occurrence in keratin disorders and this is a first report in PC. These mutations cause a distinct sub-phenotype of PC that is more severe in the offspring of affected parents and has associated alopecia.

Josef Jadassohn (1863-1936) and his assistant, Felix Lewandowsky (1879-1921), were eminent German dermatologists who had several dermatology conditions linked eponymously. One such condition is Jadassohn-Lewandowsky syndrome, which is a type of pachyonychia congenita - a disease that is characterized by severe thickening of the nail due to massive nail hyperkeratosis. This report describes Jada...

The ability to attract sufficient resources to effectively develop therapeutics for rare diseases is a daunting task. This review summarizes existing resources for rare diseases and discusses some of the challenges and strategies associated with developing therapies for small patient populations with an emphasis on pachyonychia congenita.

Pachyonychia congenita type 2 (PC-2) is an autosomal dominant disorder characterized by hypertrophic nail dystrophy, focal keratoderma, multiple pilosebaceous cysts, and other features of ectodermal dysplasia. It has been demonstrated that PC-2 is caused by mutations in the keratin 17 and keratin 6b genes. In this report, we describe a missense mutation in the keratin 17 gene, M88T, in a Korean...