The Cytocell FAST FISH Prenatal Enumeration Probe assays are designed for the rapid and accurate detection of the most common foetal chromosomal disorders. The probe set is intended for the detection and quantification of chromosomes 13, 18, 21, X and Y in interphase nuclei of uncultured amniotic fluid cells by FISH. The assay should be used in conjunction with foetal karyotype analysis.
Trisomy of chromosome 21, resulting in Down syndrome1, is one of the most common chromosome abnormalities in humans and the risk of having an affected child is known to increase with maternal age2. The syndrome represents a particular combination of phenotypic findings, including characteristic facial appearance, a single palmar crease and mental retardation, and may also present with hearing and heart defects. Affected individuals show a highly increased incidence of leukaemia, particularly acute megakaryocytic leukaemia3.
Trisomy of chromosome 18, resulting in Edwards syndrome, occurs in around 1 in 6000-8000 live births with a female sex bias4. The clinical findings are variable, though many exhibit growth delay, heart defects and craniofacial anomalies, as well as possible limb and kidney abnormalities5.
The rarest trisomy, trisomy 13, responsible for Patau syndrome occurs in approximately 1 in 16,000 newborns6. Individuals with Patau syndrome present abnormalities affecting many parts of the body, including the heart, spinal cord, eyes, limbs, face/skull and muscles6.
Aberrant copy numbers of the X and Y chromosomes can lead to various sex chromosome disorders, such as Klinefelter (47,XXY), Turner (45,X) and other syndromes caused by variations in copy number of X and/or Y. These syndromes have variable incidences and clinical findings7.
Cytocell Prenatal kits contain fluorescent probes for easy identification of trisomies 21, 18 and 13 present in Down, Edwards and Patau syndrome, respectively, as well as multiple sex chromosome aneuploidies.
Probe set 1
X centromere, Xp11.1 – q11.1 (DXZ1) Green
Y centromere, Yp11.1 – q11.1 (DYZ3) Orange
18 centromere, 18p11.1 – q11.1 (D18Z1) Blue