Chromosomes are the packages within cells that contain a person’s genetic information (called “genes” or “DNA”). This genetic information tells a person’s body how to develop and function properly. Gains (duplications) or losses (deletions) result in extra or missing copies of genetic material. These types of changes in a person’s chromosomes may be associated with known genetic conditions or may cause problems with health and development, such as birth defects or cognitive impairment.

This test is appropriate for testing of parents and siblings of a child with an uncertain or abnormal result by traditional cytogenetic testing (karyotype, FISH) or chromosomal microarray (SNP array, array CGH). Based on the results of the child’s testing, one of the following cytogenetic follow-up tests can be performed: SNP array, interphase or metaphase FISH, qPCR, or limited karyotype. The appropriate follow-up test is typically indicated on the child’s test report.