title: Detection of fetal HLA-DQa sequences in maternal blood: a gender-independent technique of fetal cell identification.
abstract: The objective of this study was to detect fetal HLA-DQa gene sequences in maternal blood. HLA-DQa genotypes of 70 pregnant women and their partners were determined for type A1. We specifically sought couples where the father, but not the mother, had genotype A1. In 12 women, maternal blood samples were flow-sorted. Candidate fetal cells were isolated and amplified by using PCR primers specific for a paternal HLA-DQa A1 allele. Fetal HLA-DQa A1 genotype was predicted from sorted cells; amniocytes or cheek swabs were used for confirmation. Six of twelve sorted samples had amplification products indicating the presence of the HLA-DQa A1 allele; 6/12 did not. Prediction of the fetal genotype was 100 per cent correct, as determined by subsequent amplification of amniocytes or cheek swabs. We conclude that paternally inherited uniquely fetal HLA-DQa gene sequences can be identified in maternal blood. This system permits the identification of fetal cells independent of fetal gender, and has the potential for non-invasive prenatal diagnosis of paternally inherited conditions.
authors.affiliation: Department of Obstetrics and Gynecology, Medical Center Hospital of Vermont, Burlington, USA.
authors.forename: O
authors.initials: O
authors.lastname: Geifman-Holtzman
authors.forename: E J
authors.initials: EJ
authors.lastname: Holtzman
authors.forename: T J
authors.initials: TJ
authors.lastname: Vadnais
authors.forename: V E
authors.initials: VE
authors.lastname: Phillips
authors.forename: E L
authors.initials: EL
authors.lastname: Capeless
authors.forename: D W
authors.initials: DW
authors.lastname: Bianchi
mesh_terms: D001483:Base Sequence; D001773:Blood Cells / Q000166:cytology; D002469:Cell Separation; D004247:DNA / Q000097:blood* / Q000737:chemistry; D005260:Female; D005312:Fetal Blood / Q000166:cytology; D005434:Flow Cytometry; D005838:Genotype; D006683:HLA-DQ Antigens / Q000235:genetics*; D059848:HLA-DQ alpha-Chains; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D012723:Sex
chemical_list: D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; C069050:HLA-DQA1 antigen; D004247:DNA