The objective of this study was to characterize the genetic abnormalities in two fetuses with
congenital anomalies in prenatal screening.
Materials and methods: The mother of Fetus 1 was 26 years old and had a second trimester serum
screening that indicated the fetus was at low risk. The prenatal ultrasound and magnetic resonance
imaging (MRI) at 28 weeks of gestation showed mild ventriculomegaly, microcephaly, and agenesis of
the corpus callosum. The mother of Fetus 2 was 25 years old and also had a second trimester serum
screening that indicated the fetus was at low risk. The prenatal ultrasound at 32 weeks of gestation
showed the presence of hyperechogenic and enlarged kidneys with multicystic renal dysplasia bilaterally
and a persistent left superior vena cava (PLSVC). Both pregnant women underwent cord blood samplings
because of the abnormal imaging results. Karyotype analysis revealed normal results in the two fetuses.
Chromosome microarray analysis (CMA) was then performed to provide genetic analysis of the cord
blood and parental blood samples. Ultimately, the pregnancies were both terminated.
Results: CMA detected a 1.56-Mb duplication at 17q12 in Fetus 1 and a 1.93-Mb deletion of 17q12 in Fetus
2. Both the duplicated and deleted regions included the HNF1B and LHX1 genes. Neither the duplication
nor deletion was inherited from the parents.
Conclusion: This study is the first to report the prenatal diagnosis of a 17q12 duplication syndrome. Our
results further confirmed that genes in this region, including HNF1B and LHX1, are essential for normal
brain and kidney development, and also indicated some genes that may be associated with the cardiovascular
abnormality. Combined with imaging examination, the use of CMA will improve the diagnosis
of submicroscopic chromosomal aberrations in fetuses with congenital anomalies.
Copyright © 2014, Taiwan Association of Obstetrics & Gynecology. Published by Elsevier Taiwan LLC. All
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