Characterization of i(18p) in prenatal diagnosis by fluorescence in situ hybridization.
A case is presented in which chorionic villus direct preparation and cultured chorionic villus cells revealed a 47,XX+mar karyotype. The marker was a small metacentric chromosome and appeared to be i(18p)--isochromosome 18p. Follow-up studies in both amniotic fluid and fetal fibroblasts confirmed the karyotype. In order to characterize the marker, a panel of biotinylated DNA probes was used, including a whole chromosome 18 probe, chromosome 18-specific alpha satellite DNA, Yac clones, and a pan-telomeric probe. These studies show that the marker is a monocentric i(18p) in which about 80 per cent of chromosome 18 alpha satellite DNA has been lost.
Yu
L C
LC
Department of Laboratory Medicine, University of California, San Francisco.
Williams
J
J
Wang
B B
BB
Vooijs
M
M
Weier
H U
HU
Sakamoto
M
M
Ying
K L
KL
D000328:Adult; D015193:Chorionic Villi Sampling / Q000379:methods*; D002869:Chromosome Aberrations; D002887:Chromosomes, Human, Pair 18; D005260:Female; D005456:Fluorescent Dyes; D006801:Humans; D017403:In Situ Hybridization; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis / Q000379:methods*
D005456:Fluorescent Dyes