Chromosomal Analysis

Indications for Testing

Advanced maternal age
Previous child or pregnancy with chromosomal abnormality
Abnormal ultrasound
Abnormal maternal serum screen
Fetal demise
Multiple miscarriage
Mental retardation or developmental delay
Dysmorphism
Congenital anomalies
Male or female infertility

Testing Methodology

G-band chromosomal analysis is performed on all blood specimens. High resolution analysis is performed when indicated. Additional chromosome banding techniques are utilized when necessary. Cell cultures are established from all amniotic fluid, chorionic villi, and tissue specimens followed by G-band chromosome analysis.

Specimen Requirements

Prenatal Studies

Amniotic fluid: Collect 20 – 25 cc in a 50 ml sterile conical centrifuge tube.

Chorionic villi: Collect 15 – 20 mg villi in a T-25 tissue culture flask containing sterile tissue culture media.

Postnatal Studies

Blood: For adults and children, 3 – 5 cc collected in a sodium heparin (green top) vacutainer tube. For newborns, 1 - 2 cc is sufficient. Do not centrifuge or freeze. Store sample at room temperature.

Other Tissue Studies

Collect 5 mm tissue in sterile culture media.