American Society for Clinical Pathology (ASCP) Technologist in Cytogenetics certification (ASCP CG) Practice Test

Which type of specimen is ideal for cytogenetic analysis for Turner syndrome?

1. Heparinized peripheral blood stored at room temperature

2. Bone marrow aspirate

3. Frozen peripheral blood

4. Unprocessed tissue sample

The correct answer is: Heparinized peripheral blood stored at room temperature

The ideal specimen for cytogenetic analysis for Turner syndrome is heparinized peripheral blood stored at room temperature. Peripheral blood is widely used for cytogenetic studies due to its accessibility and the fact that it contains lymphocytes, which can be cultured to analyze chromosomes. When blood is collected in heparinized tubes, it prevents clotting, allowing the lymphocytes to remain viable for culture. Turner syndrome is associated with a specific chromosomal abnormality, typically the loss of one X chromosome in females (45,X), and analyzing peripheral blood lymphocytes provides a reliable method to identify such karyotypic changes. Maintaining the sample at room temperature is important as it allows the cells to remain physiologically active during transport to the laboratory for further processing. Other specimen types, such as bone marrow aspirate or unprocessed tissue samples, may be used in specific circumstances, but they are generally less favorable for standard cytogenetic analysis due to the complexity of collection, potential degradation of cellular integrity, or lower yields of viable cells. Frozen peripheral blood is not optimal because freezing can damage the cells, making them unsuitable for analysis. Therefore, the heparinized peripheral blood sample is the most advantageous for accurate cytogenetic evaluation in cases of Turner