Ichthyosis hystrix an autosomal dominant condition caused by a mutation to the GJB2 gene (the same gene affected by KID syndrome). An extremely rare disease of which only a few isolated cases are known. Ichthyosis hystrix Ichthyosis hystrix is a group of rare skin disorders in the ichthyosis family of skin disorders characterized by massive hyperkeratosis with an appearance like spiny scales. This term is also used to refer to a type of epidermal nevi with extensive bilateral distribution. The symptoms of ichthyosis hystrix Curth-Macklin are similar to epidermolytic hyperkeratosis (NPS-2 type) but there is no blistering and the hyperkeratosis is verrucous
Ichthyosis hystrix though some experts believe that it may have been a type of epidermolytic hyperkeratosis. From the history of the Lambert family the disease appears to have been an autosomal dominant condition. HID syndrome is also known as ichthyosis hystrix, Rheydt type after the German city of Rheydt near Düsseldorf where it was first discovered. Symptoms are bilateral hearing loss and spiky hyperkeratotic masses which cover the whole body though the palms and soles are less badly affected. It can be differentiated from KID syndrome which also has symptoms of deafness and ichthyosis by the different distribution of hyperkeratosis. It is