The second frameshift mutation causing a distinct C-terminal truncation, LBR c.1599-1605TCTTCTA->CTAGAAG (LBR p.X534), which we have designated as LBR 1600*, has been shown to cause Pelger-Huët anomaly in heterozygous individuals as well as Greenberg skeletal dysplasia when both LBR alleles are mutated (Waterham et al., 2003). This evidence concerns the gene LBR and skeletal dysplasia.