Partial trisomy of the long arm of human chromosome 1 as demonstrated by in situ hybridization with 5S ribosomal RNA

Abstract

In a newborn boy with multiple malformations, a tandem duplication was detected at the distal end of the long arm of one human chromosome 1. The Giemsa bands, lq31 to lq43-44, were repeated serially. Since 5S rRNA genes are located at lq42-43, in situ hybridization of ~25I 5S rRNA with fixed chromosome preparations was used to confirm the chromosomal duplication. The infant exhibited numerous developmental and clinical abnormalities as might be expected with an abnormality of chromosome structure relating to a ribosome component.

Duplication Dup(1)(q32q44) Detected by Comparative Genomic Hybridization (CGH): Further Delineation of Trisomies 1q

“…5 patients from three families showing a terminal duplication distal to 1q42 [16,20,23] were summarized in group IV. In one case the duplication involved 1q segments of groups I-IV [8] (fig. 4).…”

Boy with an interstitial 1q (q31q41) duplication confirmed by fluorescent in situ hybridisation

“…The largest duplication of chromosome 1 reported in a live-born child involved the region 1q24-qter [Zuffardi et al, 1977]. Interstitial duplications of 1q are rarely seen [Flatz and Fonatsch, 1979;Furforo et al, 1996;Lungarotti et al, 1980;Palmer et al, 1977;Schinzel, 1979;Steffensen et al, 1977]. In most of reported cases with duplications of chromosome 1 a rearrangement has occurred with involvement of another chromosome as results from unbalanced translocations [Chia et al, 1988;DuPont et al, 1994;Fryns et al, 1980;Johnson, 1991;Kennerknecht et al, 1993;Liberfarb et al, 1979;Rasmussen et al, 1990;Rehder and Friedrich, 1979;Rosenthal et al, 1987;Schinzel, 1981;Watson et al, 1990;Verschuuren-Bemelmans et al, 1995].…”

De novo interstitial direct duplication 1(q23.1q31.1) in a fetus with Pierre Robin sequence and camptodactyly

“…In those cases, it is dif®cult to separate the trisomy 1q phenotype from that of the other involved chromosome. Cases with duplication involving chromosome 1q alone, when a de novo structural rearrangement has occurred, are not very common [Garver et al, 1976;Palmer et al, 1977;Pan et al, 1977;Steffenssen et al, 1977;Flatz and Fonatsch, 1979;Schinzel, 1979;Lungarotti et al, 1980;Mewar et al, 1994;Duba et al, 1997;Lukusa et al, 1998;Sillen et al, 1998], but are the most informative for delineating a duplication 1q syndrome. Moreover, it is necessary to characterize correctly the duplicated region in order to establish a genotype-phenotype correlation, particularly by using molecular cytogenetic techniques.…”