Genomic Microarray AnalysisâArray Comparative Genomic Hybridization (aCGH)

This technology uses probes covering the entire genome and can detect chromosome abnormalities up to 10 times smaller than those detectable by conventional chromosome analysis.

Use

Detection of chromosome abnormalities (copy number changes; e.g., deletion, duplication) up to 10 times smaller than can be detected by conventional chromosome analysis

Detection of abnormalities that may be causal for developmental delay, autism, and congenital anomalies. Some laboratories are offering aCGH for prenatal diagnosis.

Cancer-appropriate arrays are also in clinical use.

Interpretation

Normal: Two copies for all tested sequences in diploid cells

Abnormal: Copy number < or >2

Limitations

aCGH cannot detect balanced rearrangements that may play a role in repeat pregnancy loss and cancer.

Interpretation of results is not always straightforward; some detected imbalances may be of no clinical significance. Variant databases are in development.