Chromosomal abnormalities cause problems
Small chromosomal variations can lead to excess or shortage of genes within that region, thus resulting in a person with medical problems, such as abnormal growth, development, and abnormal function of the body’s systems. Besides, chromosome numeral or structural variants can result in a person with diseases such as Down syndrome, Prader-Willi syndrome, and DiGeorge syndrome. Pregnancy at an advanced age increases the fetal risk of chromosomal abnormality.
Primary prenatal diagnostic test for fetal ultrasound abnormalities and abnormal screening result.
SNP microarray has been established as a useful diagnostic tool in pregnancy to detect fetal chromosomal abnormality. It could detect more chromosomal abnormalities than other existing testing methods and provides more comprehensive genetic information of the fetus.
When to consider Prenatal SNP microarray?
The American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) recommend that all pregnant women should be offered prenatal assessment for aneuploidy by screening or diagnostic testing regardless of maternal age or other risk factors. (Reference: Obstet Gynecol 2016;127:e108-22.)
It is recommended for pregnant women who:
- desires definitive and comprehensive information about fetus.
- have a family history of congenital anomalies or a previous pregnancy with a fetus with chromosomal abnormalities.
- have abnormal prenatal findings from ultrasound scans, karyotype, and other screening tests (e.g. NIPT, First/Second-trimester maternal serum Down Syndrome screening).
- Non-invasive Prenatal Test (NIPT) showing no-call or inconclusive results due to low fetal fraction.
- carries multiple gestations.
- achieved pregnancy by Preimplantation Genetic Testing for Aneuploidy (PGT-A).
Amniotic fluid: 10-15mL
*Other sample requirements (CVS or DNA) can be discuss further
GGA Prenatal SNP microarray with both CNV and SNP markers could identify genomic copy number changes and homozygosity, such as Absence of Heterozygosity (AOH), Uniparental Disomy (UPD), and triploidy, to help determine the genetic causes of abnormal findings and/or abnormal screening result.
Why choose GGA Prenatal SNP microarray?
- Combines copy number markers with SNP markers at a high density to provide the highest resolution and coverage.
- Able to detect more chromosomal abnormalities such as AOH, UPD and triploidy in one test.
- Provide comprehensive genetic counseling support to clinicians.
- CAP-accredited laboratory with over 12 years of experience in genetic testing.
- GGA clinical studies^ yield a rich collection of genetic and clinical data on SNP microarray.
- J FORMOS MED ASSOC. Mar 2019, 118(3), 739-742
- Pediatrics and Neonatology. (2020) 61, 343-345
- Acta Obstet Gynecol Scand. 2020 Jun;99(6):775-782.