Meier-Gorlin syndrome and Wolf-Hirschhorn syndrome: two developmental disorders highlighting the importance of efficient DNA replication for normal development and neurogenesis.

[wolf-hirschhorn syndrome]

Microcephaly represents one of the most obvious clinical manifestations of impaired neurogenesis . Defects in the DNA damage response , in DNA repair , and structural abnormalities in centrosomes , centrioles and the spindle microtubule network have all been demonstrated to cause microcephaly in humans . Work describing novel functional defects in cell lines from individuals with either Meier-Gorlin syndrome or Wolf-Hirschhorn syndrome highlight the significance of optimal DNA replication and S phase progression for normal human development , including neurogenesis . These findings illustrate how different primary defects in processes impacting upon DNA replication potentially influence similar phenotypic outcomes , including growth retardation and microcephaly . Herein , we will describe the nature of the S phase defects uncovered for each of these conditions and highlight some of the overlapping cellular features .