title: Quinacrine fluorescence and Giemsa banding in trisomy 22.
abstract: Using quinacrine fluorescence and Giemsa banding techniques we have identified an extra chromosome 22 in three non-mongoloid children with similar phenotypes and 47 chromosomes. In one of the children, the long arm of the extra 22 was shorter than usual. This 22q-chrcmcscme was observed in 4 normal family members with 46 chromosomes. In a fourth child, with similar physical findings, the extra G chromosome was shown to be neither a normal 21 nor 22. It must have arisen from a rearrangement in a parental gamete since it was not present in either parent's karyotype.No constellation of clinical findings, in association with an extra G chromosome, is sufficient evidence for the diagnosis of trisomy 22. The positive identification of the extra chromosome must be made using fluorescence and banding.
authors.affiliation: St. Christopher's Hospital for Children, Department of Pediatrics, Temple University Medical School, USA.
authors.forename: H H
authors.initials: HH
authors.lastname: Punnett
authors.forename: M L
authors.initials: ML
authors.lastname: Kistenmacher
authors.forename: M A
authors.initials: MA
authors.lastname: Toro-Sola
authors.forename: G
authors.initials: G
authors.lastname: Kohn