Routine Cytogenetic
Analysis Of Peripheral Blood
Specimen requirements: 5 - 10 ml peripheral blood in a sodium
heparin (green top) Vacutainer™ tube. In newborn
infants, 1 to 2 ml of blood may be sufficient. Certain anticoagulants,
such as lithium heparin and ammonium heparin, may be toxic to
lymphocytes; therefore sodium heparin is the anticoagulant of
choice. Certain types of blood collection tubes have also been
associated with reduced cell growth, therefore Vacutainer TM
tubes, as opposed to Venoject™ tubes, are preferred for specimen
collection.
Transport: Specimen should be kept at room temperature;
do not freeze or refrigerate. Specimen should be sent
by courier or overnight mail to arrive at the laboratory within
24 hours.
Analysis: A minimum of 20 cells are counted and 5 cells
are analyzed from G-banded preparations. Hard copies of two karyotypes
and 3 chromosome spreads are retained for documentation.
Report: Results are available in 14-21 days. For STAT
samples, results are available in 2 to 4 days.
CPT Codes: 88230, 88262, 88291
High
Resolution Chromosome Analysis of Peripheral Blood
High resolution chromosome analysis
requires the use of elongation methods to obtain a high percentage
of prophase and prometaphase spreads. The chromosomes are less
condensed than in routine metaphase analysis and the number of
identifiable bands is expanded, allowing a more sensitive analysis
of the karyotype. Because special culture conditions are required,
high resolution studies must be specifically requested. For sample
requirements, see above.
This study is required for the detection of subtle chromosome
rearrangements and is considered an important component in the
diagnosis of microdeletion syndromes such as Prader-Willi syndrome,
Angelman syndrome, Smith-Magenis syndrome, and Miller-Dieker
syndrome.
Transport:
Specimen should be kept at room temperature; do not freeze
or refrigerate. Specimen should be sent by courier or overnight
mail to arrive at the laboratory within 24 hours.
Analysis:
A minimum of 20 cells are counted and 5 cells are analyzed from
G-banded preparations. Hard copies of two karyotypes and 3 chromosome
spreads are retained for documentation.
Report:
Results are available in 14 to 21 days. For STAT samples, results
are available in 2 to 4 days.
CPT codes:
88230, 88262, 88289, 88291
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