Clinically, NS is characterised by a triad of ichthyosiform erythroderma (often evolving from congenital ichthyosiform erythroderma to ichthyosis linearis circumflexa); pathognomonic hair shaft abnormalities, such as trichorrhexis invaginata (“bamboo hair”); and atopic manifestations with elevated serum IgE. The gene discussed is IGHE; the disease is ichthyosis linearis circumflexa.