TY - JOUR
T1 - FISH characterization of two supernumerary r(1) associated with distinct clinical phenotypes
AU - Giardino, Daniela
AU - Bettio, D.
AU - Gottardi, G.
AU - Rizzi, N.
AU - Pierluigi, M.
AU - Perfumo, C.
AU - Calì, A.
AU - Dagna Bricarelli, F.
AU - Larizza, L.
PY - 1999/6/4
Y1 - 1999/6/4
N2 - Only a few reports on supernumerary r(1) chromosomes associated with a clinical phenotype have been published. We describe two unrelated patients with congenital malformations and developmental delay who were found to have a de novo supernumerary r(1) in 50% (Case 1) and 80% (Case 2) of the examined cells. Conventional cytogenetic techniques (QFQ, CBG, and DA- DAPI), complemented by fluorescence in situ hybridization studies using alpha satellite probes, showed that both small marker chromosomes (SMCs) primarily consisted of the centromere and heterochromatin of chromosome 1, a conclusion that was also supported by chromosome 1 painting. In an attempt to establish phenotype-genotype correlations, a further investigation was performed using YACs mapped to the chromosome 1 pericentromeric region. A fluorescent signal was evident after hybridization with Y934G9 (1q21) in Case 1 and Y959C4 (1p11.1.12) in Case 2. Partial trisomy of unique sequences flanking pericentromeric sequences is shown to underlie the clinical phenotype in both patients. This evidence should be taken into account when SMCs are ascertained, particularly in prenatal diagnosis.
AB - Only a few reports on supernumerary r(1) chromosomes associated with a clinical phenotype have been published. We describe two unrelated patients with congenital malformations and developmental delay who were found to have a de novo supernumerary r(1) in 50% (Case 1) and 80% (Case 2) of the examined cells. Conventional cytogenetic techniques (QFQ, CBG, and DA- DAPI), complemented by fluorescence in situ hybridization studies using alpha satellite probes, showed that both small marker chromosomes (SMCs) primarily consisted of the centromere and heterochromatin of chromosome 1, a conclusion that was also supported by chromosome 1 painting. In an attempt to establish phenotype-genotype correlations, a further investigation was performed using YACs mapped to the chromosome 1 pericentromeric region. A fluorescent signal was evident after hybridization with Y934G9 (1q21) in Case 1 and Y959C4 (1p11.1.12) in Case 2. Partial trisomy of unique sequences flanking pericentromeric sequences is shown to underlie the clinical phenotype in both patients. This evidence should be taken into account when SMCs are ascertained, particularly in prenatal diagnosis.
KW - Chromosome 1 partial trisomy
KW - Clinical phenotype
KW - De novo
KW - Marker chromosome
KW - Supernumerary r(1)
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U2 - 10.1002/(SICI)1096-8628(19990604)84:4<377::AID-AJMG14>3.0.CO;2-U
DO - 10.1002/(SICI)1096-8628(19990604)84:4<377::AID-AJMG14>3.0.CO;2-U
M3 - Article
C2 - 10340656
AN - SCOPUS:0033522780
VL - 84
SP - 377
EP - 380
JO - American Journal of Medical Genetics, Part A
JF - American Journal of Medical Genetics, Part A
SN - 1552-4825
IS - 4
ER -