Cytogenetic characterization of an extra structurally abnormal chromosome associated with severe mental retardation: inv dup (15) (q13).
We have studied an extra structually abnormal chromosome (ESAC) in a 13 years old boy with profound mental, psychomotor and speech retardation, behavioral problems, seizures and abnormal electroencephalogram. The examination of the bisatellited ESAC with chromosome banding demonstrated that the karyotype was: 47, XY, +inv dup (15) (pter-->q13::q13-->pter). The cytogenetic characterization of the inv dup (15) is reported with special emphasis on the usefulness of DA/DAPI staining when G-banding is sequentially performed to discard possible heteromorphisms in DA/DAPI positive chromosomes, and the importance of Ag-NOR heteromorphisms to ascertain the maternal origin of the inv dup (15). A U-type exchange between two non-sister chromatids is proposed as its mechanism of formation. The clinical features of the case were consistent with those previously reported in similar cases.
Gorla
N
N
Universidad Nacional de Río Cuarto (UNRC), Argentina.
Slavutsky
I
I
Lisanti
J
J
Pedrazzini
E
E
Vanella
L
L
Larripa
I
I
D000293:Adolescent; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D007446:Chromosome Inversion; D002874:Chromosome Mapping; D002884:Chromosomes, Human, Pair 15; D020440:Gene Duplication; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics* / Q000473:pathology; D007621:Karyotyping; D008297:Male; D001523:Mental Disorders / Q000235:genetics; D012640:Seizures / Q000235:genetics; D013064:Speech Disorders / Q000235:genetics