Complex chromosomal rearrangements: some breakpoints may have cellular adaptive significance.

Cytogenetic study of a 3-year-old girl with developmental delay and some minor abnormalities revealed a complex chromosome rearrangement (CCR) involving seven chromosomes with eight breakpoints, leading to monosomy of segment 5q15-q22. According to breakpoint distribution, CCRs may be classified as those with primary intrachromosomal abnormalities (including inversions, insertions, duplications, etc.) and those without them.

Phenotypic variability of del(2) (q22-q23): report of a case with a review of the literature.

An interstitial deletion of 2q22-q23 was found in a 2.5 year old boy with multiple congenital abnormalities (including Hirschsprung's disease) and severe mental retardation. Comparison with seven additional cases of 2q deletions from the literature does not allow the delineation of a clinically recognizable syndrome.