De novo balanced complex chromosome rearrangement (CCR) involving chromosome 8, 11 and 16 in a boy with mild developmental delay and psychotic disorder.
Congenital Complex Chromosome rearrangements (CCRs) compatible with life are rare in humans. We report a de novo CCR involving chromosomes 8, 11 and 16 with 4 breakpoints in a patient with mild dysmorphic features, acquisition delay and psychotic disorder. Conventional cytogenetic analysis revealed an apparently balanced 8;16 translocation. Further FISH analysis with WCP 8 and WCP 16 probes revealed the presence of a third chromosome involved in the translocation. The multicolour karyotype confirmed the complexity of the rearrangement and showed that the derivative chromosome 8 was composed of 3 distinct segments derived from chromosomes 8, 16 and 11. The breakpoints of this complex rearrangement were located at 8q21, 11q14, 11q23 and 16q12. Comparative genomic hybridization (CGH) and array-CGH were performed to investigate the possibility of any genomic imbalance as a result of the complex rearrangement. No imbalance was detected by these two techniques. Our study showed: i) the necessity to confirm reciprocal translocations with FISH using painting probes, particularly when the karyotype resolution is weak; ii) the usefulness of multicolour karyotype for the characterization of structural chromosomal rearrangements, particularly when they are complex; iii) the usefulness of CGH and array-CGH in cases of abnormal phenotype and apparently balanced rearrangement in order to explore the breakpoints and to detect additional imbalances.
Goumy
C
C
Cytogénétique Médicale, CHU / Faculté de Médecine, Clermont-Ferrand, France. carole.goumy@u-clermont1.fr
Mihaescu
M
M
Tchirkov
A
A
Giollant
M
M
Benier
C
C
Francannet
C
C
Jaffray
J Y
JY
Geneix
A
A
Vago
P
P
D002648:Child; D002869:Chromosome Aberrations; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics*; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics*; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics*; D002658:Developmental Disabilities / Q000150:complications* / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D011618:Psychotic Disorders / Q000150:complications* / Q000175:diagnosis / Q000235:genetics*