Prenatal diagnosis of ornithine transcarbamylase deficiency by using a single nucleated erythrocyte from maternal blood.
We have developed a method that allows the prenatal DNA diagnosis of ornithine transcarbamylase (OTC) deficiency by using a single fetal nucleated erythrocyte (NRBC) isolated from maternal blood. OTC gene analysis of a male patient (TF) with early onset OTC deficiency was performed by single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing. To investigate the possible prenatal diagnosis of OTC deficiency, maternal blood was obtained at 13 weeks of gestation of a subsequent pregnancy, from the mother of patient TF. NRBCs in the maternal blood were separated by using the density gradient method and then collected with a micromanipulator. The entire genome of a single NRBC was amplified by primer extension preamplification (PEP). The human leukocyte antigen (HLA)-DQ alpha genotype and sex were determined from small aliquots of the PEP product. The HLA-DQ alpha genotype of each of the parents of the male patient was also determined. Once a single NRBC had been identified as being of fetal origin, the OTC gene was analyzed by using the restriction fragment length polymorphism (RFLP) method. DNA analysis revealed a point mutation in exon 9 of the OTC gene in the OTC-deficient patient (TF). All NRBCs retrieved from maternal blood were successfully identified as being of fetal origin by HLA-DQ alpha genotyping and sex determination. RFLP analysis demonstrated that the fetal OTC gene was normal. This is the first study to successfully diagnose OTC deficiency prenatally, by using a single fetal NRBC from the maternal circulation. Such prenatal DNA diagnosis is non-invasive and can be applied to other genetic diseases, including autosomal and X-linked diseases.
Department of Obstetrics and Gynecology, Showa University, School of Medicine, Tokyo, Japan.
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A
Watanabe
A
A
Sekizawa
A
A
Taguchi
H
H
Saito
T
T
Yanaihara
M
M
Shimazu
I
I
Matsuda
D004912:Erythrocytes / Q000166:cytology / Q000201:enzymology*; D005260:Female; D005312:Fetal Blood / Q000201:enzymology*; D005315:Fetal Diseases / Q000097:blood / Q000175:diagnosis / Q000201:enzymology*; D006683:HLA-DQ Antigens / Q000032:analysis; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009954:Ornithine Carbamoyltransferase / Q000097:blood; D020163:Ornithine Carbamoyltransferase Deficiency Disease; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D011247:Pregnancy; D011296:Prenatal Diagnosis; D019849:Sex Determination Processes
D006683:HLA-DQ Antigens; D009954:Ornithine Carbamoyltransferase