A new type of pachyonychia congenita

We describe two patients with an apparently unique autosomal dominant ectod ermal dysplasia, Symptoms consist of thickening of all nails as seen in pac hyonychia congenita and severe generalized hypotrichosis, No other abnormal ities were present. Histopathological examination of scalp skin showed a re duction in the number of hair follicles, but other abnormalities were not f ound. Direct sequencing of the keratins known to be associated with pachyon ychia congenita, Krt 6a, 6b, 16 and 17, failed to detect mutations. This su ggests that this may be a new type of pachyonychia caused by a mutation in a so-called hard keratin,