| Amniotic fluid is analyzed
when the maternal age > 35 years, previous abortions
or missed abortions, paternal chromosomal structural
abnormalities, malformation, diagnostic findings (PAPP-A,
Trple test), abnormal ultrasound, previous delivery
of children with chromosomal abnormalities, previous
delivery of children with malformation, mutagenic exposure
during pregnancy.
FISH testing extends routine cytogenetic banding methods
by resolving ambiguous diagnosis and providing a new
tool to diagnose submicroscopic abnormalities. FISH
is a relatively simple, fast, and reliable procedure.
Depending on the sequence complexity of labeled DNA
probe and the content of tested specimen, FISH has variable
signal sensitivity and spatial resolution. Hybridization
probes range from very small DNA fragments (500 bp)
to large Yeast Artificial Chromosomes (YACs) or Bacterial
Artificial Chromosomes (BACs). The spatial resolution
measured by the closest separable signals could range
from 5 Mbp on metaphase chromosomes to 100 Kbp on interphase
chromatins. The most important features of FISH techniques
are its applicability on different specimens and its
utilization on the simultaneous detection using multiple
probes. Specimens that can be used for FISH include
peripheral blood cells, cultured cell lines, bone marrow
cells, paraffin-embedded tissue sections, and frozen
tissues.
Applications of FISH for hematological disorders include
delineation of chromosomal numerical abnormalities;
detection of specific translocations such as those involving
immunoglobulin genes in lymphomas, and other translocation
seen in leukemias; determining degree of engraftment
following sex-mismatched bone marrow and cord blood
transplants; determining the origin of specific translocations
and marker chromosomes using paint probes in cases where
G-banding cannot identify the origin; and revealing
cases with gene amplification.
Amniotic fluid cytogenetic evaluation is appropriate
for indications of advanced maternal age and other genetic
indications at 13-18 weeks gestation (occasionally later
for ultrasound findings of anomalies).
Amniotic Fluid culture + FISH (5 probes)
Amniotic fluid is analyzed when the maternal age > 35
years, previous abortions or missed abortions, paternal
chromosomal structural abnormalities, malformation, diagnostic
findings (PAPP-A, Trple test), abnormal ultrasound, previous
delivery of children with chromosomal abnormalities, previous
delivery of children with malformation, mutagenic exposure
during pregnancy.
FISH testing extends routine cytogenetic banding methods
by resolving ambiguous diagnosis and providing a new tool
to diagnose submicroscopic abnormalities. FISH is a relatively
simple, fast, and reliable procedure. Depending on the
sequence complexity of labeled DNA probe and the content
of tested specimen, FISH has variable signal sensitivity
and spatial resolution. Hybridization probes range from
very small DNA fragments (500 bp) to large Yeast Artificial
Chromosomes (YACs) or Bacterial Artificial Chromosomes
(BACs). The spatial resolution measured by the closest
separable signals could range from 5 Mbp on metaphase
chromosomes to 100 Kbp on interphase chromatins. The most
important features of FISH techniques are its applicability
on different specimens and its utilization on the simultaneous
detection using multiple probes. Specimens that can be
used for FISH include peripheral blood cells, cultured
cell lines, bone marrow cells, paraffin-embedded tissue
sections, and frozen tissues.
Applications of FISH for hematological disorders include
delineation of chromosomal numerical abnormalities; detection
of specific translocations such as those involving immunoglobulin
genes in lymphomas, and other translocation seen in leukemias;
determining degree of engraftment following sex-mismatched
bone marrow and cord blood transplants; determining the
origin of specific translocations and marker chromosomes
using paint probes in cases where G-banding cannot identify
the origin; and revealing cases with gene amplification.
Amniotic fluid cytogenetic evaluation is appropriate for
indications of advanced maternal age and other genetic
indications at 13-18 weeks gestation (occasionally later
for ultrasound findings of anomalies).
Chromosome 21/13 only or (X, Y, 18)
Amniotic fluid is analyzed when the maternal age >
35 years, previous abortions or missed abortions, paternal
chromosomal structural abnormalities, malformation, diagnostic
findings (PAPP-A, Trple test), abnormal ultrasound, previous
delivery of children with chromosomal abnormalities, previous
delivery of children with malformation, mutagenic exposure
during pregnancy.
FISH testing extends routine cytogenetic banding methods
by resolving ambiguous diagnosis and providing a new tool
to diagnose submicroscopic abnormalities. FISH is a relatively
simple, fast, and reliable procedure. Depending on the
sequence complexity of labeled DNA probe and the content
of tested specimen, FISH has variable signal sensitivity
and spatial resolution. Hybridization probes range from
very small DNA fragments (500 bp) to large Yeast Artificial
Chromosomes (YACs) or Bacterial Artificial Chromosomes
(BACs). The spatial resolution measured by the closest
separable signals could range from 5 Mbp on metaphase
chromosomes to 100 Kbp on interphase chromatins. The most
important features of FISH techniques are its applicability
on different specimens and its utilization on the simultaneous
detection using multiple probes. Specimens that can be
used for FISH include peripheral blood cells, cultured
cell lines, bone marrow cells, paraffin-embedded tissue
sections, and frozen tissues.
Applications of FISH for hematological disorders include
delineation of chromosomal numerical abnormalities; detection
of specific translocations such as those involving immunoglobulin
genes in lymphomas, and other translocation seen in leukemias;
determining degree of engraftment following sex-mismatched
bone marrow and cord blood transplants; determining the
origin of specific translocations and marker chromosomes
using paint probes in cases where G-banding cannot identify
the origin; and revealing cases with gene amplification.
Cytogenetic evaluation of stimulated blood is appropriate
for patients in whom constitutional structural or numerical
chromosome abnormalities are suspected. This includes:
Multiple congenital anomalies or dysmorphic features,
failure to thrive, developmental delay, unexplained mental
retardation, family history of a chromosome abnormality,
primary or secondary amenorrhea, couples experiencing
multiple pregnancy losses or infertility, etc.
Chromosome 21/ Chromosome
16 / or Chromosome X& Y
Amniotic fluid is analyzed when the maternal age > 35
years, previous abortions or missed abortions, paternal
chromosomal structural abnormalities, malformation, diagnostic
findings (PAPP-A, Trple test), abnormal ultrasound, previous
delivery of children with chromosomal abnormalities, previous
delivery of children with malformation, mutagenic exposure
during pregnancy.
FISH testing extends routine cytogenetic banding methods
by resolving ambiguous diagnosis and providing a new tool
to diagnose submicroscopic abnormalities. FISH is a relatively
simple, fast, and reliable procedure. Depending on the
sequence complexity of labeled DNA probe and the content
of tested specimen, FISH has variable signal sensitivity
and spatial resolution. Hybridization probes range from
very small DNA fragments (500 bp) to large Yeast Artificial
Chromosomes (YACs) or Bacterial Artificial Chromosomes
(BACs). The spatial resolution measured by the closest
separable signals could range from 5 Mbp on metaphase
chromosomes to 100 Kbp on interphase chromatins. The most
important features of FISH techniques are its applicability
on different specimens and its utilization on the simultaneous
detection using multiple probes. Specimens that can be
used for FISH include peripheral blood cells, cultured
cell lines, bone marrow cells, paraffin-embedded tissue
sections, and frozen tissues.
Applications of FISH for hematological disorders include
delineation of chromosomal numerical abnormalities; detection
of specific translocations such as those involving immunoglobulin
genes in lymphomas, and other translocation seen in leukemias;
determining degree of engraftment following sex-mismatched
bone marrow and cord blood transplants; determining the
origin of specific translocations and marker chromosomes
using paint probes in cases where G-banding cannot identify
the origin; and revealing cases with gene amplification.
Cytogenetic evaluation of stimulated blood is appropriate
for patients in whom constitutional structural or numerical
chromosome abnormalities are suspected. This includes:
Multiple congenital anomalies or dysmorphic features,
failure to thrive, developmental delay, unexplained
mental retardation, family history of a chromosome abnormality,
primary or secondary amenorrhea, couples experiencing
multiple pregnancy losses or infertility, etc. |
