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

What is the minimum band level necessary to detect Prader-Willi syndrome?

1. 300

2. 400

3. 550

4. 600

The correct answer is: 550

The minimum band level necessary to detect Prader-Willi syndrome is 550. This syndrome is often identified through chromosomal analysis that relies on high-resolution banding techniques. Prader-Willi syndrome results primarily from the deletion of paternal chromosome 15q11-q13, and these chromosomal alterations require a sufficient level of detail to visualize subtle changes accurately. A band level of 550 provides the necessary resolution to identify such deletions or other rearrangements associated with the syndrome. At this resolution, laboratory personnel can distinguish fine structural details that are crucial for diagnostic purposes. In contrast, lower banding levels like 300 or 400 do not offer sufficient detail and may miss clinically significant findings. Consequently, maintaining a band level of at least 550 is essential for reliable detection of Prader-Willi syndrome through cytogenetic analysis.