Partial trisomy 17q22-qter and partial monosomy Xq27-qter in a girl with
a de novo unbalanced translocation due to a postzygotic error: Case
report and review of the literature on partial trisomy 17qter
Partial trisomy 17q22-qter is a rare but well-recognized clinical
entity, We present a case of partial trisomy for the long arm of
chromosome 17, which was detected in a female infant with severe
psychomotor and somatic retardation, Stargardt disease, short limbs, and
numerous minor anomalies. Differential chromosomal staining demonstrated
an excess of genetic material on the long arm of the late replicating X
chromosome, FISH and DNA polymorphism analysis showed that the extra
material belonged to the distal part of the long arm of chromosome 17
and that there was a partial monosomy of the distal part of the long arm
of the derivative X chromosome, The breakpoint regions of this
translocation were identified by molecular analysis using polymorphic
microsatellite markers on human chromosomes 17 and X The origin of the
abnormal X chromosome was found to be paternal, whereas the origin of
the duplicated part of chromosome 17 was maternal, The unbalanced
translocation between the paternal X and the maternal chromosome 17 is,
therefore, suggested to be due to a postzygotic error. (C) 1997
Wiley-Liss, Inc
