Colonies, Amniotic fluid

Laboratory assay overview

This test is used for prenatal detection of chromosome abnormalities in at-risk pregnant women. AFP analysis of midtrimester amniotic fluid for detection of open neural tube and ventral wall defects. This test reflexes to AChE and fetal hemoglobin if AF-AFP is abnormal. While chromosome analysis is being performed, additional biochemical or molecular analysis can be performed.

Laboratory assay overview

This test is used to determine fetal karyotype, prenatal diagnosis of Down syndrome or other chromosomal abnormalities; and analysis of midtrimester amniotic fluid for detection of open neural tube and ventral wall defects.

Laboratory assay overview

The test determines fetal karyotype. The test allows prenatal detection of chromosomal rearrangements, aneuploidy, or mosaicism. Such groups include women who: • are age 35 years of age or older • have a previous child having chromosome abnormality or multiple congenital abnormalities • have had two or more previous spontaneous abortions • have a family history of a chromosome abnormality • are known carriers of an X-linked disorder • are 31 years of age or older with twin pregnancies • have abnormal fetal ultrasound findings • have a positive maternal serum marker screen Additional biochemical or molecular tests may be performed on the cultured amniocytes.

Laboratory assay overview

The chromosome analysis determines fetal karyotype. A normal chromosome analysis will reflex to a high-resolution SNP microarray analysis targeting 2.8 million copy-number and allele-specific genome sites. The SNP assay will detect chromosomal imbalances that could be associated with developmental delay/congenital anomalies. It provides possible detection of uniparental disomy of any chromosome, the percent and location of homozygosity, including the degree of identity by descent.

Laboratory assay overview

The test allows prenatal detection of chromosomal aneuploidy, and is used to rule out tetraploidy and rearrangements not detected by array, such as balanced translocations and inversions. It also helps to clarify array abnormalities to determine if a structural rearrangement, marker, or isochromosome is present. Array can only provide copy number imbalances and cannot determine structure of an abnormality. The SNP assay will detect chromosomal imbalances that could be associated with developmental delay/congenital anomalies. It provides detection of possible uniparental disomy of any chromosome, the percent and location of homozygosity, including the degree of identity by descent.