High Density SNP Microarray (Postnatal)
Potential Test Results:
- A normal result indicates no clinically-significant chromosome anomalies were identified.
- arr[hg19](1-22,X)x2 (female)
- arr[hg19](1-22)x2,(XY)x1 (male)
- Results are reported by location in the genome, including chromosome and size.
- Deletion: Part of a chromosome (genetic material) is missing. Some may be very small and only include one gene and others are bigger and may involve numerous genes.
- Duplication: Extra chromosome material is present in the patient’s DNA.
- An abnormal result indicates that a chromosome abnormality was identified that likely provides an explanation for the indications.
- Pathogenic – Reported when a copy number variant (CNV) is:
- associated with a known microdeletion/microduplication syndrome,
- cytogenetically visible or > 3 Mb,
- documented in multiple peer-reviewed publications.
- Uncertain Clinical Significance (UCS) – In some circumstances, the clinical significance of a finding may not be well understood. Uncertain variants may also be classified as “Likely Pathogenic” or “Likely Benign” based on the ACMG recommendations for variant classification.1
- ROH – Reported when it represents uniparental disomy (UPD), when it represents >1.5% of the entire genome and when a segment of ROH is >3Mb.
- Parental testing (Postnatal Chromosome Analysis on maternal and/or paternal blood) may be recommended in order to clarify whether the result is de novo or familial for the purpose of recurrence risk calculation.
- Richards et al. Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genet Med advance online publication 5 March 2015; 1-20.