Interestingly, mounting evidence indicates that Greenberg skeletal dysplasia results from the inheritance of two mutant LBR alleles that when heterozygous cause Pelger-Huët anomaly (Konstantinidou et al., 2008; Oosterwijk et al., 2003), indicating that the two diseases represent different allelic states of the same chromosomal lesion. The gene discussed is LBR; the disease is skeletal dysplasia.