German researchers identify protein and organelle that cause Microcephaly

A team of researchers led by Erich Nigg at the Biozentrum of the University of Basel in Germany identified a cell signal critical to cell division, according to an article on MedicalXpress posted on Jan. 31, 2014.

One of the centromeres, the organelles that help chromosomes migrate to the appropriate regions during mitosis, duplicates before cell division occurs with the help of a protein known as STIL.

Nigg's team identified KEN-Box, a cell signal that triggers the degradation of STIL after the centromere has been duplicated.

If KEN-Box does not signal degradation at the right time, the centomeres may continue to divide.  If this occurs, a multi-polar mitotic division occurs and chromosomes are not distributed properly.

This depicts a multi-polar division in which the there are four centrioles (red) attempting to divide the chromosomes (blue). (Photo credit: MedicalXpress)

When this occurs in brain cells (neurons), Microcephaly may occur, a syndrome usually marked by an abnormally small head and often mental and developmental problems and delays, as explained by the National Institute of Neurological Disorders and Stroke.

This may be linked to drug and alcohol abuse during pregnancy, although the mechanism for such interaction has yet to be proposed.