Molecular cytogenetic characterization and origin of two de novo duplication 9p cases

Abstract

We report on two additional cases with duplication of 9p, minor with facial anomalies and developmental delay. Using fluorescence in situ hybridization and single-copy probes, we showed that the first case was a direct duplication, whereas the second case was inverted. The extent of the direct duplication was defined as 9p12 --> p24 by microdissection and microcloning of the aberrant chromosome and subsequent chromosome-specific comparative genomic hybridization. DNA polymorphism analysis with eight microsatellite markers revealed that the origin of the dup(9p) was maternal in the first case, whereas it was paternal in the second.

Cytogenetic and Array-CGH Characterization of a Complex de novo Rearrangement Involving Duplication and Deletion of 9p and Clinical Findings in a 4-Month-Old Female

“…However, most of these reported duplications are due to malsegregation of chromosomes inherited from a parent with a reciprocal translocation involving chromosome 9, with relatively few pure 9p duplications arising de novo [Chiyo et al, 1976; Baccichetti et al, 1979; Fryns et al, 1979; Motegi et al, 1985; Mattina et al, 1987; Haddad et al, 1996; Fujimoto et al, 1998; Tsezou et al, 2000; Bonaglia et al, 2002; Krepischi-Santos and Vianna-Morgante, 2003; Swinkels et al, 2008]. Despite varying sizes of duplicated chromosomal segments, there is a significant overlap in clinical features in duplication 9p syndrome, which is attributed to the terminal segment of 9p.…”

“…In most of these patients, the duplication 9p is a result of an abnormal chromosome segregation of a balanced translocation in one of the parents [Baccichetti and Tenconi, 1973; Wajntal et al, 1985]. De novo duplications of this chromosomal region have been previously described in approximately 15 patients [Chiyo et al, 1976; Baccichetti et al, 1979; Fryns et al, 1979; Motegi et al, 1985; Mattina et al, 1987; Haddad et al, 1996; Fujimoto et al, 1998; Tsezou et al, 2000; Krepischi-Santos and Vianna-Morgante, 2003]. Patients with partial trisomy of the short arm of chromosome 9 often display a wide spectrum of clinical symptoms including developmental delay, craniofacial abnormalities (bulbous nose, hypertelorism, downward-slanting palpebral fissures), limb abnormalities (short fingers and toes with small nails, fifth-finger clinodactyly) and skeletal malformations.…”

Characterization of partial trisomy 9p due to insertional translocation by chromosomal (micro)FISH

“…A patient with trisomy 9p12‐p22 was described who showed a clinical pattern, especially of the face and hands, suggesting trisomy 9p syndrome (5). Several authors described patients with characteristic clinical features of trisomy 9p syndrome and a duplication of the 9p12‐p24 region (6–10). A patient with a de novo duplication of 9p13‐p22 also showed the typical clinical stigmata of the 9p syndrome (11).…”

Molecular characterisation of a mosaicism with a complex chromosome rearrangement: evidence for coincident chromosome healing by telomere capture and neo-telomere formation

“…21 Rearrangements of chromosome 9 do not show site-specific breakpoints. [22][23][24][25][26] Therefore, NHEJ seems to be the most likely mechanism for rearrangements of chromosome 9p. 27 In silico sequence analysis of chromosomes 5 and 9 showed the existence in the breakpoint region 5p13.3 of L1PA2, a LINE sequence with homology with L1PA3 in the breakpoint regions in 9p13.3 and in 9p22.1 and with L1PA7 in 9p22.1.…”