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Objective: The etiology of congenital talipes equinovarus (CTEV) is unknown, and the relationship between chromosome microdeletion/microduplication and fetal CTEV is rarely reported. In this study, we retrospectively analyzed fetal CTEV to explore the relationship among the CTEV phenotype, chromosome microdeletion/microduplication, and obstetric outcomes. Methods: Chromosome karyotype analysis and single nucleotide polymorphism (SNP) array were performed for the 68 fetuses with CTEV. Results: An SNP array was performed for 68 fetuses with CTEV; pathogenic copy number variations (CNVs) were detected in eight cases (11.8%, 8/68). In addition to one case consistent with karyotype analysis, the SNP array revealed seven additional pathogenic CNVs, including three with 22q11.21 microdeletions, two with 17p12p11.2 microduplications, one with 15q11.2 microdeletions, and one with 7q11.23 microduplications. Of the seven cases carrying pathogenic CNVs, three were tested for family genetics; of these, one was de novo, and two were inherited from either the father or mother. In total, 68 fetuses with CTEV were initially identified, of which 66 cases successfully followed-up. Of these, 9 were terminated, 2 died in utero, and 55 were live births. In 9 cases, no clinical manifestations of CTEV were found at birth; the false-positive rate of prenatal ultrasound CTEVdiagnosis was thus 13.6% (9/66). Conclusion: CTEV was associated with chromosome microdeletion/microduplication, the most common of which was 22q11.21 microdeletion, followed by 17p12p11.2 microduplication. Thus, further genomic detection is recommended for fetuses with CTEV showing no abnormalities on conventional karyotype analysis. [ABSTRACT FROM AUTHOR]

The phenotypes of Xp22.33 or Yp11.32 microdeletions comprising the short-stature homeobox (SHOX) gene have been extensively described in adults and children. Herein, the prenatal ultrasound phenotype and pregnancy outcomes of fetuses with Xp22.33/Yp11.32 microdeletions were analyzed to improve our understanding, diagnosis, and monitoring of this genetic condition in the fetal stage. A total of 9,100 pregnant women referred to tertiary units for prenatal diagnosis were evaluated by chromosomal microarray analysis(CMA). Seven (0.08 %) fetuses had Xp22.33/Yp11.32 microdeletions, ranging from 243 kb to 1.1 Mb, that comprised SHOX. The ultrasonic phenotypes differed among these fetuses, with three fetuses presenting abnormal bone development, one had labial-palatal deformity and strawberry head, two had an abnormal ultrasonic soft marker, and one had no abnormalities. After genetic counseling, only one couple underwent pedigree assessment, which confirmed the paternal origin of the microdeletion. This infant presented delayed speech development, whereas other three infants showed a typical postnatal development. In three cases, the parents chose to terminate the pregnancy. The ultrasonic phenotype of fetuses with Xp22.33/Yp11.32 microdeletions resulting in SHOX heterozygosity loss is variable. Prenatal CMA can quickly and effectively diagnose Xp22.33/Yp11.32 microdeletions and SHOX loss, which may help prenatal counseling. [ABSTRACT FROM AUTHOR]

Background: The genetic etiology of congenital pulmonary stenosis (PS) in fetuses remains inadequately studied. We used karyotype analysis and chromosomal microarray analysis (CMA) to investigate the genetic aberrations associated with PS in human fetuses. Methods: A retrospective analysis was performed on 84 fetuses with congenital PS in southern China. Fetal amniotic fluid and umbilical cord blood samples were obtained for chromosomal karyotype analysis and CMA. Results: The rate of pathogenic copy number variation (CNV) was 15.5% (13/84) after karyotyping and CMA. An abnormal karyotype was detected in five cases (6.0%, 5/84) via karyotyping, whereas pathogenic CNVs were detected in 13 cases (15.5%, 13/84) via CMA. In addition to the five abnormal karyotypes detected using karyotype analysis, eight additional chromosomal microduplications and microdeletions were detected using CMA, comprising three cases of 22q11.21 microdeletion; two cases of 16p11.2 microdeletion; one case of simultaneous 18q23 microdeletion and 22q13.33 microduplication; one case of 15q24.1q24.2 microdeletion; and one case of 1q21.1q21.2 microduplication. The rate of pathogenic CNV occurrence was 11.5% in fetuses with isolated PS and 17.2% in fetuses with PS combined with other ultrasound abnormalities. This difference between the two experimental groups was statistically significant. Among 84 fetuses with PS, 39 pregnancies were terminated, and five were lost to follow-up. Conclusions: CMA was not only conducive to detect PS-related pathogenic genomic abnormalities but also to accurately evaluate fetal prognosis in genetic counseling. The early detection of PS and genomic abnormalities will exerta positive impact on fetal intervention and the related prognosis of PS in perinatal infants. [ABSTRACT FROM AUTHOR]

Objective Single-molecule real-time technology (SMRT) is a sequencing technology using the DNA polymerases and fluorescently tagged nucleotides to accurately sequence DNA strands. The purpose of this study was to evaluate the detection accuracy of SMRT for identification of the Hong Kongαα (HKαα) thalassemia allele. Methods We conducted a blinded study of 33 samples of known HKαα alleles. These alleles were detected using SMRT to evaluate accuracy. Results We conducted a blinded study of 33 known HKαα samples and found all HKαα variants detected by SMRT to be concordant with those independently assigned by gap-polymerase chain reaction (gap-PCR), reverse dot blot hybridization, and 2-round nested PCR. In addition, SMRT detected 2 β-thalassemia variants that were missed by conventional techniques. Conclusion The results demonstrate that SMRT offers a higher detection accuracy of thalassemia rare and new loci. It is an efficient, reliable, and broad-spectrum test that can be widely used for thalassemia screening in the clinic. [ABSTRACT FROM AUTHOR]