Non-invasive prenatal detection of achondroplasia using circulating fetal DNA in maternal plasma

Abstract

Purpose: To perform a reliable non-invasive detection of the fetal achondroplasia using maternal plasma.

Methods: We developed a quantitative fluorescent-polymerase chain reaction (QF-PCR) method suitable for detection of the FGFR3 mutation (G1138A) causing achondroplasia. This method was applied in a non-invasive detection of the fetal achondroplasia using circulating fetal-DNA (cf-DNA) in maternal plasma. Maternal plasmas were obtained at 27 weeks of gestational age from women carrying an achondroplasia fetus or a normal fetus.

Results: Two percent or less achondroplasia DNA was reliably detected by QF-PCR. In a woman carrying a normal fetus, analysis of cf-DNA showed only one peak of the wild-type G allele. In a woman expected an achondroplasia fetus, analysis of cf-DNA showed the two peaks of wild-type G allele and mutant-type A allele and accurately detected the fetal achondroplasia.

Conclusions: The non-invasive method using maternal plasma and QF-PCR may be useful for diagnosis of the fetal achondroplasia.

Fig. 1

QF-PCR results in a pregnant woman with a normal fetus (n = 1). Maternal genomic DNA, fetal genomic DNA and cf-DNA showed only one peak for the 161-bp fragment representing the wild-type G allele of the FGFR3 mutation (G1138A). QF-PCR result of cf-DNA was confirmed by direct sequencing

Fig. 2

QF-PCR results in a pregnant woman with an achondroplasia fetus (n = 1). Maternal genomic DNA showed only one peak for the 161-bp fragment representing the wild-type G allele of the FGFR3 mutation (G1138A). However, the fetal genomic DNA and cf-DNA accurately showed two peaks including a 107-bp fragment representing the mutant-type A allele and a 161-bp fragment representing the wild-type G allele of the FGFR3 mutation (G1138A). QF-PCR result of cf-DNA was confirmed by direct sequencing