Cytogenomic SNP Microarray - Fetal

Casandra

Casandra Test Code AR70659Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 2002366CPT Codes 81229, 81265

Cytogenomic SNP Microarray - Fetal

Also known as: ARRAY FE

Clinical Use

Order Test

Use

The Cytogenomic SNP Microarray - Fetal is a diagnostic test intended to identify genomic abnormalities such as aneuploidy and microdeletions. It is used in the prenatal setting to detect chromosomal abnormalities and potential genetic disorders such as Wolf-Hirschhorn syndrome. The test evaluates genomic imbalances by analyzing DNA copy number variations (CNVs), regions of homozygosity indicating potential uniparental disomy, and ploidy alterations, which can be indicative of issues like triploidy or molar pregnancy. The array provides comprehensive genomic coverage and can identify deletions or duplications that could explain chromosomal abnormalities or contribute to genetic disorders.

Special Instructions

Counseling and informed consent are recommended before genetic testing, particularly for patients from New York, where special submission procedures apply. The test requires a Cytogenetic test request form and a Prenatal Cytogenetics Patient History Form. Arrangements for maternal contamination studies should be considered when ordering.

Limitations

This analysis does not provide detailed structural information concerning genomic imbalances. It cannot detect low-level mosaicism, sequence variants like point mutations, or balanced chromosomal rearrangements. Some genomic alterations may fall below the detection limit of the array. As a result, additional testing such as FISH or chromosome analysis may be advised for comprehensive assessment. The array's detection limit for mosaicism is above 20-30% presence in a sample.

Test Details

Methodology

Microarray

Biomarkers

The test uses a genomic microarray platform to detect DNA copy number changes, regions of homozygosity, and uniparental disomy across the genome, with enhanced detection capabilities through 2.67 million genome-spanning markers.