First case of a neocentromere formation in an otherwise normal chromosome 7.

According to cytogenetic and molecular cytogenetic characterization, an otherwise not-altered chromosome 7 formed a neocentromere in band 7q32.1 in a clinically normal female. The alpha satellite sequence D7Z1 remained in its place but was not used for formation of the primary chromosomal incision. Similar observations of centromere repositioning have been made for chromosomes 3 (2x), 4, 8 and Y (2x). Even though data is available for some neocentromeres whose positions are correlated with evolutionary new centromeres for 7q32.1, no correlation could be found for an ancestral inactivated centromere in any of the presently living primates. Overall, we report a new case of centromere repositioning at a position not known to harbor an ancestral inactivated centromere. 2009 S. Karger AG, Basel.