A Turner syndrome case associated with dic(Y;22).

Background: Constitutional telomeric associations are very rare events and the mechanism underlying their development is not well understood.

Case Presentation: We here describe a female case of Turner syndrome with a 45,X,add(22)(p11.2)[25]/45,X[5].

The involvement of U-type dicentric chromosomes in the formation of terminal deletions with or without adjacent inverted duplications.

An inverted duplication with a terminal deletion (inv-dup-del) is one of the complex constitutional structural rearrangements that can occur in a chromosome. Although breakages of dicentric chromosome have been suggested, the precise mechanism of this is yet to be fully understood. In our present study, we investigated the genomic structure of 10 inv-dup-del cases to elucidate this mechanism.

A case of a parthenogenetic 46,XX/46,XY chimera presenting ambiguous genitalia.

Sex-chromosome discordant chimerism (XX/XY chimerism) is a rare chromosomal disorder in humans. We report a boy with ambiguous genitalia and hypospadias, showing 46,XY[26]/46,XX[4] in peripheral blood cells. To clarify the mechanism of how this chimerism took place, we carried out whole-genome genotyping using a SNP array and microsatellite analysis.