66
MORIMASA MATSUTA AND MAYUMI MATS UTA
tion of all human chromosomes in 24 different colors. This method demostrates the characterization of de novo structural chromosomal abnormalities (Schroeck et al. 1997).
The newly developed cytogenetic technique, comparative
genomic hybridization (CGH), produces a map of the DNA sequence copy number as a function of chromosomal location
throughout the entire genome (Kallioniemi 1994,1993,1992).
Test DNA and normal reference DNA are differentially labeled
with two fluorochromes, and the DNAs are hybridized simultaneously to normal chromosome spreads. Regions of gain or loss
of DNA, such as deletions, duplications, or amplifications, are
seen as changes in the ratio of the intensities of the two fluorochromes along the target chromosomes.
Preimplantation, prenatal, and postnatal genetic diagnosis
Pre implantation and prenatal diagnosis is a procedure for the
diagnosis of genetic diseases by screening pregnancies or in
vitro-fertilized embryos for chromosome abnormalities. A number of techniques are used for the specific diagnosis of inherited
disorders, such as the polymerase chain reaction. FISH can be
used for the preimplantation, prenatal, and postnatal diagnosis
of abnormal numbers of chromosomes and chromosome rearrangement.
Pre implantation genetic diagnosis is performed when the embryo is at the 6-10 cell stage when embryos are generated by standard in vitro fertilization. One or two blastmeres are obtained
from the cleavage-stage embryo biopsy, and are used for diagnOSIS.
Prenatal genetic diagnosis is performed by chorionic villi
sampling (CVS) or amniocentesis. Method for the application
of FISH to cells derived from CVS and is performed at 10-12
weeks of pregnancy. Controlled studies are necessary, however,
to appreciate the impact of the moderately common condition of
chromosomal mosaicism found in CVS samples. Amniocentesis
involves the aspiration of a small volume of amniotic fluid. Chromosomes are analyzed by karyotyping, although it can take more
than 3 weeks to obtain the relevant genetic information. FISH
allows for the rapid detection of major genetic abnormalities,
which will eliminate the anxious waiting weeks. This technique
MORIMASA MATSUTA AND MAYUMI MATS UTA
tion of all human chromosomes in 24 different colors. This method demostrates the characterization of de novo structural chromosomal abnormalities (Schroeck et al. 1997).
The newly developed cytogenetic technique, comparative
genomic hybridization (CGH), produces a map of the DNA sequence copy number as a function of chromosomal location
throughout the entire genome (Kallioniemi 1994,1993,1992).
Test DNA and normal reference DNA are differentially labeled
with two fluorochromes, and the DNAs are hybridized simultaneously to normal chromosome spreads. Regions of gain or loss
of DNA, such as deletions, duplications, or amplifications, are
seen as changes in the ratio of the intensities of the two fluorochromes along the target chromosomes.
Preimplantation, prenatal, and postnatal genetic diagnosis
Pre implantation and prenatal diagnosis is a procedure for the
diagnosis of genetic diseases by screening pregnancies or in
vitro-fertilized embryos for chromosome abnormalities. A number of techniques are used for the specific diagnosis of inherited
disorders, such as the polymerase chain reaction. FISH can be
used for the preimplantation, prenatal, and postnatal diagnosis
of abnormal numbers of chromosomes and chromosome rearrangement.
Pre implantation genetic diagnosis is performed when the embryo is at the 6-10 cell stage when embryos are generated by standard in vitro fertilization. One or two blastmeres are obtained
from the cleavage-stage embryo biopsy, and are used for diagnOSIS.
Prenatal genetic diagnosis is performed by chorionic villi
sampling (CVS) or amniocentesis. Method for the application
of FISH to cells derived from CVS and is performed at 10-12
weeks of pregnancy. Controlled studies are necessary, however,
to appreciate the impact of the moderately common condition of
chromosomal mosaicism found in CVS samples. Amniocentesis
involves the aspiration of a small volume of amniotic fluid. Chromosomes are analyzed by karyotyping, although it can take more
than 3 weeks to obtain the relevant genetic information. FISH
allows for the rapid detection of major genetic abnormalities,
which will eliminate the anxious waiting weeks. This technique