- Chromosome Analysis of:
- Amniotic Fluid
- Bone Marrow
- Neoplastic Peripheral Blood
- Non-Neoplastic Peripheral Blood
- Products of Conception
- Tissue
- Solid Tumor
Classic
Cytogenetics - Chromosome Analysis
Oncology
Chromosome analyses for hematological disorders of bone marrow and/or
leukemic blood are performed to identify specific chromosome rearrangements.
These rearrangements in neoplastic cells are often correlated to specific
types of leukemia, pre-leukemias, or myelodysplasias. This information
aids the clinician in diagnosis, predicting prognosis, and guiding treatment.
Examples of targeted abnormalities include: t(9;22) [CML, ALL], t(15;17)
[AML-M3], inv(16) [AML-M4], del(5q) [myelodysplasia, secondary AML]. Cytogenetic
studies of bone marrow involve culturing of fresh specimen. Giemsa-banded
chromosomes are analyzed from 20 or more metaphase cells. A minimum of
two representative karyotypes are produced. Additional cell counts and
banding techniques are performed when required.
Non-oncology
Cytogenetic studies of peripheral blood also involve culturing of fresh
specimen. Giemsa-banded chromosomes are analyzed from 20 or more metaphase
cells. A minimum of two representative karyotypes are produced. Additional
cell counts and banding techniques are performed when required. If mosaicism
is suspect, additional metaphase cells are evaluated. Chromosome analysis
on peripheral blood specimens may be performed for several indications:
including multiple congenital anomalies in a patient; couples with a history
of spontaneous miscarriages; individuals with ambiguous genitalia, infertility,
or amenorrhea; patients with a family history of chromosomal abnormalities;
patients with a suspected chromosomal syndrome; and families with male
predominant mental retardation.
Sub-chromosomal Testing
Molecular Cytogenetics ( FISH )
Fluorescence in situ hybridization (FISH) utilizes fluorescent-labeled
DNA probes to defined chromosomal sequences (e.g., translocation breakpoint
cluster regions, centromeric sequences) to identify translocations, deletions,
and amplifications of genes as well as changes in chromosome number. Whereas
traditional cytogenetic analysis requires metaphase (dividing) cell preparations
and is subject to the limitations of detection by light microscopy, FISH
can be applied to either metaphase or interphase (non-dividing) cell preparations.
FISH analyses allow visualization of an abnormal chromosomal complement
that otherwise might go undetected (e.g., in a hematologic population
where cells are not dividing or in a patient who has a cryptic translocation
or microdeletion). FISH can be performed for specific abnormalities including:
translocation breakpoints in leukemia/lymphoma [t(9;22), t(15;17), inv(16),
t(14;18), etc.]; marker chromosome identification, mosaicism studies,
and prenatal detection of aneuploidy.
