High-resolution banding is particularly useful for diagnosing which condition?

High-resolution banding is particularly beneficial for diagnosing DiGeorge syndrome because it allows for the detection of subtle chromosomal abnormalities, specifically microdeletions. DiGeorge syndrome is often associated with a 22q11.2 deletion, which can be challenging to identify using standard karyotyping techniques. High-resolution banding provides an enhanced view of chromosomes, enabling cytogeneticists to observe and analyze smaller chromosomal changes that may be present in conditions like DiGeorge syndrome.

In contrast, conditions like Turner syndrome, Down syndrome, and Fragile X syndrome typically involve more prominent chromosomal abnormalities that can be identified through standard karyotyping or other testing methods. Turner syndrome is characterized by the absence of one X chromosome, Down syndrome is associated with an extra copy of chromosome 21 (trisomy 21), and Fragile X syndrome is linked to mutations in the FMR1 gene. These conditions do not require the same level of resolution for diagnosis that high-resolution banding provides. Thus, the technique is most applicable for identifying the microdeletion characteristic of DiGeorge syndrome.