Heterozygous LBR mutations lead to nuclear hyposegmentation of neutrophils without causing disease [6,59,87], while homozygous LBR mutations cause various malformations ranging from cardiac defects, brachydactyly and mental retardation (homozygous Pelger–Huët anomaly), severe skin disease (ichthyosis in mice) and prenatal death (Greenberg dysplasia) [6,87]. Here, LBR is linked to ichthyosis.