Kabuki syndrome-like features associated with a small ring chromosome X and XIST gene expression.

TitleKabuki syndrome-like features associated with a small ring chromosome X and XIST gene expression.
Publication TypeJournal Article
Year of Publication2001
AuthorsStankiewicz P, Thiele H, Giannakudis I, Schlicker M, Baldermann C, Krüger A, Dörr S, Starke H, Hansmann I
JournalAmerican journal of medical genetics
Date Published2001 Aug 15

Although clinical features in Kabuki syndrome (KS; Niikawa-Kuroki syndrome) have been well defined, the underlying genetic mechanism still remains unclear. We report a 9-year-old girl with typical KS-like facial appearance, skeletal and dermatoglyphic abnormalities, severe mental retardation, and growth deficiency. In 60 of 100 GTG-banded metaphases from peripheral blood lymphocytes, a ring chromosomei smaller than a G group chromosome was found, which, according to reverse painting, consisted of Xq11.1q13. The proband's karyotypei was described as mos45,X/46,X,+r(X). Several loci were analyzed with fluorescence in situ hybridization (FISH) and microsatellite markers revealing that one r(X) breakpoint mapped proximal to DXS422 (Xp11.21) and the second mapped distali to XIST gene, between loci DXS128E and DXS441 (Xq13.2). Uniparental disomy for X and r(X) was excluded and the paternal origin of r(X) was identified. XIST expression was demonstrated by nested reverse transcription polymerase chain reaction (RT-PCR) using primers spanning exons 5, 6i, and 6 in RNA prepared from lymphocytes. The observation of XIST expression is in contrast to two other cases in which the XIST gene was either not present on r(X) or not expressed. To our knowledge, this is the first case of Kabuki-like syndrome manifestations with r(X) and XIST expression.

Alternate JournalAm. J. Med. Genet.
Citation Key11484209