Chromatin is the packaged form of DNA in the eukaryotic cell. It consists almost entirely of repeating units, called nucleosomes, in which short segments of DNA are wrapped tightly around a disk-like structure comprising two subunits of each of the histone proteins H2A, H2B, H3 and H4.

Histone proteins are covalently modified by a number of different adducts (i.e. acetylation and phosphorylation) that regulate the tightness of the DNA-histone interactions.

Mutations in genes encoding enzymes that mediate chromatin structure can result in a loss of proper regulation of chromatin structure, which in turn can result in deregulation of gene transcription and inappropriate protein expression.

Classification

 X-linked alpha-thalassemia/mental retardation syndrome (ATR-X)
 Rett syndrome
 immunodeficiency-centromeric instability-facial anomalies syndrome (ICF)
 Rubinstein-Taybi syndrome
 Coffin-Lowry syndrome

References

 Gibbons RJ. Histone modifying and chromatin remodelling enzymes in cancer and dysplastic syndromes. Hum Mol Genet. 2005 Apr 15;14 Spec No 1:R85-92. PMID: #15809277#

 Cho KS, Elizondo LI, Boerkoel CF. Advances in chromatin remodeling and human disease. Curr Opin Genet Dev. 2004 Jun;14(3):308-15. PMID: #15172675#

 Bickmore WA, van der Maarel SM. Perturbations of chromatin structure in human genetic disease: recent advances. Hum Mol Genet. 2003 Oct 15;12 Spec No 2:R207-13. PMID: #12915455#

 Ausio J, Levin DB, De Amorim GV, Bakker S, Macleod PM. Syndromes of disordered chromatin remodeling. Clin Genet. 2003 Aug;64(2):83-95. PMID: #12859401#