title: Identifying Robertsonian Translocation Carriers by Microarray-Based DNA Analysis.
abstract: OBJECTIVE
  To develop a noninvasive prenatal testing improvement that allows identification of Robertsonian translocation carriers.
  
  
  METHODS
  Blood samples from 191 subjects, including 7 pregnant and 9 non-pregnant Robertsonian translocation carriers, were analyzed for fetal trisomy and Robertsonian translocation status. Digital Analysis of Selected Regions (DANSR™) assays targeting sequences common to the p arms of 5 acrocentric chromosomes were developed and added to existing DANSR assays. DANSR products were hybridized onto a custom DNA microarray for DNA analysis. The Fetal-Fraction Optimized Risk of Trisomy Evaluation (FORTE™) algorithm measures the fraction of fetal DNA and accounts for both the fetal and maternal fractions in the cell-free DNA sample to determine Robertsonian risk. The expectation in a Robertsonian translocation carrier is that DANSR assays on acrocentric p arms should have a concentration 20% less than that of controls.
  
  
  RESULTS
  The FORTE algorithm correctly classified the fetal trisomy status and maternal Robertsonian translocation status in all 191 samples. Sixteen samples had a Robertsonian risk score above 99%, while 175 samples had a Robertsonian risk score below 0.01%.
  
  
  CONCLUSIONS
  Robertsonian translocations are the most common chromosomal translocations and can have significant reproductive consequences. A maternal screen for Robertsonian translocation carriers would provide women valuable information regarding the risk of fetal trisomy.
authors.affiliation: Ariosa Diagnostics Inc., San Jose, Calif., USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Huang
authors.forename: Kara
authors.initials: K
authors.lastname: Juneau
authors.forename: Patrick E
authors.initials: PE
authors.lastname: Bogard
authors.forename: Kelli A
authors.initials: KA
authors.lastname: Davies
authors.forename: Eric T
authors.initials: ET
authors.lastname: Wang
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Kingsley
authors.forename: Craig A
authors.initials: CA
authors.lastname: Struble
authors.forename: Arnold
authors.initials: A
authors.lastname: Oliphant
authors.forename: Jacob M
authors.initials: JM
authors.lastname: Zahn
authors.forename: Kypros H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D000328:Adult; D000465:Algorithms; D005260:Female; D006580:Genetic Carrier Screening / Q000379:methods*; D006579:Heterozygote; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods; D014178:Translocation, Genetic; D014314:Trisomy / Q000175:diagnosis