• Journal of Genetic Medicine
• /
• v.14 no.1
• /
• pp.1-7
• /
• 2017

Purpose: The aim of this study was to assess the diagnostic efficacy of noninvasive prenatal screening for trisomy 18 by assessing the levels of unmethylated-maspin (U-maspin) and fetal nuchal translucency (NT) thickness during the first trimester of pregnancy. Materials and Methods: A nested case-control study was conducted using maternal plasma samples collected from 65 pregnant women carrying 11 fetuses with trisomy 18 and 54 normal fetuses. We compared the U-maspin levels, NT thicknesses, or a combination of both in the first trimester between the case and control groups. Results: U-maspin levels and NT thickness were significantly elevated in the first trimester in pregnant women carrying fetuses with trisomy 18 when compared to those carrying normal fetuses (27.2 vs. 6.6 copies/mL, P<0.001 for U-maspin; 5.9 vs. 2.0 mm, P<0.001 for NT). The sensitivities of the U-maspin levels and NT thickness in prenatal screening for fetal trisomy 18 were 90.9% and 90.9%, respectively, with a specificity of 98.1%. The combined U-maspin levels and NT thickness had a sensitivity of 100% in prenatal screening for fetal trisomy 18, with a specificity of 98.1%. Conclusion: A combination of U-maspin levels and NT thickness is highly efficacious for noninvasive prenatal screening of fetal trisomy 18 in the first trimester of pregnancy.

• Journal of Genetic Medicine
• /
• v.10 no.1
• /
• pp.52-56
• /
• 2013

Mosaic trisomy 14 syndrome is a well-known but unusual chromosomal abnormality with a distinct and recognizable phenotype. Array comparative genomic hybridization (CGH) analysis has recently become a widely used method for detecting DNA copy number changes, in place of traditional karyotype analysis. However, the array CGH shows a limitation for detecting the low-level mosaicism. Here, we report the detailed clinical and cytogenetic findings of patient with low-frequency mosaic trisomy 14, initially considered normal based on usual cut-off levels of array CGH, but confirmed by G-banding karyotyping. Our patient had global developmental delay, short stature, congenital heart disease, craniofacial dysmorphic features, and dark skin patches over her whole body. Estimated mosaicism proportion was 23.3% by G-banding karyotyping and 18.0% by array CGH.

• Journal of Genetic Medicine
• /
• v.12 no.2
• /
• pp.118-122
• /
• 2015

Noninvasive prenatal test (NIPT) is a novel screening method for the diagnosis of fetal chromosomal aneuploidies. NIPT is based on technology that detects cell-free fetal DNA in maternal plasma and analyzes it with massively parallel sequencing technology to determine whether the fetus is at risk of trisomy 21, trisomy 18, trisomy 13 or sex chromosome abnormalities (SCAs). NIPT has been reported to have sensitivity of 99% and a false positive rate of less than 1% for detecting trisomy 21 and trisomy 18. Although extension of the application of NIPT to other SCAs has been attempted, there are concerns in extending NIPT to SCAs because of maternal or fetal mosaicism, undetected maternal SCAs, and multiple pregnancies. Recently, we assessed a pregnancy with the rare Turner syndrome mosaicism 45, X/47, XXX, which was reported as 45, X with NIPT. We present the case here and briefly review the current literatures on NIPT in testing for fetal monosomy X. To the best of our knowledge, this is the first report of the 45, X/47, XXX mosaicism in Korea to be reported as 45, X by NIPT with whole genome sequencing. This case report will provide valuable information for counseling women who want to undergo NIPT.

• Journal of Genetic Medicine
• /
• v.6 no.1
• /
• pp.95-99
• /
• 2009

Prenatal diagnosis of rare autosome mosaicism involvingchromosomes other than chromosome 13, 18, 21 or the sex chromosome is encountered prognostic dilemma during genetic counseling. We report four cases of level III uncommon mosaicism of trisomy 5, 16 and 20,diagnosed prenatally. In case 1 with mosaic trisomy 20, there was a higher mosaic ratio of trisomy 20 in the repeat amniocentesis (62.1%) than in the first (36.6%) with normal fetal ultrasound finding except for a relatively small aorta on a 3-vessel view of the fetal heart. Case 2 showed a low rate of mosaic trisomy 20 (5.25%) in cultured amniocytes but normal karyotype in the repeat amniocentesis, who delivered a normal healthy baby. Case 3 showed a 13.6% of trisomy 16 mosaicism in the 30 cells of cultured amniocytes. Sixty cells from a fetal blood sample at termination showed non-mosaic 46,XX normal karyotype, while skin fibroblasts had 22.5% trisomy 16 in 40 metaphases. The autopsy showed ventricular septal defect (VSD). Case 4 with low grade mosaicism (10.5%) of trisomy 5 resulted in elective termination, though the ultrasoumd showed growsly normal fetus. Although level III mosaicism is regarded as true mosaicism, it is difficult to predict the outcome of the fetus with rare mosaic autosome trisomy. Therefore mosaic autosome trisomy of fetus should be carefully interpreted with more various approaches including repeat sampling and targeted fetal ultrasound.

• Journal of Genetic Medicine
• /
• v.12 no.2
• /
• pp.96-99
• /
• 2015

Purpose: To evaluate the performance of the Momguard noninvasive prenatal test by tracing the 'screen positive' results based on preliminary samples from Korean cohorts. Materials and Methods: This preliminary study is based on data collected by the LabGenomics Clinical Laboratory (Seongnam, Korea) with informed consent. Only pregnant women who underwent both the Momguard test and karyotyping were included in this study. Momguard test results were compared with those of the karyotyping analysis. Results: Among the 38 cases with 'screen positive' results by Momguard, 30 cases also had karyotyping results available. In three trisomy (T) 18 and three T13 cases, the Momguard results were concordant with the karyotyping results. For the T21 cases, except for one case belonging to the mid-risk zone, Momguard results from 23 out of 24 cases matched the karyotyping results. Conclusion: Momguard is a highly reliable screening tool for detecting T13, T18, and T21 cases in independent Korean cohort samples.

• Clinical and Experimental Pediatrics
• /
• v.52 no.10
• /
• pp.1171-1174
• /
• 2009

Edwards syndrome, also called trisomy 18, is one of the most common autosomal anomalies. The survival rate of patients with Edwards syndrome is very low and its characteristic findings include cardiac malformations, mental retardation, growth retardation, specific craniofacial anomalies, clenched hands, rocker-bottom feet, and omphalocele. Compared with the classic Edwards syndrome, the symptom of partial duplication of chromosome 18 is relatively mild with a good prognosis. We report the case of a baby with partial duplication 18q11.2-q12. The characteristic phenotype features of Edwards syndrome were observed in the patient. However, the symptom was milder than the typical Edwards syndrome. At present, we can expect better prognosis for this patient.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.35 no.2
• /
• pp.319-323
• /
• 2008

Edward's syndrome is a genetic disorder of 18th chromosomal trisomy. Main clinical features of this syndrome include systemic conditions, such as mental retardation, growth retardation, dyspnea, congenital heart disease, and orthopedic disorders, such as flexion deformity and rocker-bottom feet. The characteristics of fetal abnormality are hydramnios, small placenta, common umbilical artery. Infants with Edward's syndrome have very low survival rate. Almost half of them die during fetal stage. Fifty percent of them survive 2 months, and 5 to 10 percent of them survive about 1 year. A 3-year and 7 month old girl visited our dental hospital for the treatment of dental caries. Considering her systemic disease, low body weight, medical history of cardiac surgery, and difficulty in airway management, dental procedure was performed under general anesthesia. We report this case with review of literatures.

• Journal of Genetic Medicine
• /
• v.12 no.2
• /
• pp.61-65
• /
• 2015

Whole genome sequencing (WGS)-based noninvasive prenatal test (NIPT) is the first method applied in the clinical setting out of various NIPT techniques. Several companies, such as Sequenom, BGI, and Illumina offer WGS-based NIPT, each with different technical and bioinformatic approaches. Sequenom, BGI, and Illumina utilize z-, t-, and L-scores, as well as normalized chromosome values, respectively, for trisomy detection. Their outstanding performance has been demonstrated in clinical studies of more than 100,000 pregnancies. The sensitivity and specificity for detection of trisomies 13, 18, and 21 were above 98%, as reported by all three companies. Unlike other techniques, WGS-based NIPT can detect other trisomies as well as clinically significant segmental duplications/deletions within a chromosome, which could expand the scope of NIPT. Incorrect results could be due to low fetal fraction, fetoplacental mosaicism, confined placental mosaicism or maternal copy number variation (CNV). Among those, maternal CNV is a significant contributor of false positive results and therefore genome wide scanning plays an important role in preventing the occurrence of false positives. In this article, the bioinformatic techniques and clinical performance of three major companies are comprehensively reviewed.

• Journal of Genetic Medicine
• /
• v.4 no.2
• /
• pp.190-195
• /
• 2007

Purpose : FISH is suggested as a useful tool for rapid detection of specific aneuploidy in uncultured amniocytes abnormality in interphase nucleus. In this study, we are going to share our experience using FISH in prenatal diagnosis and suggest the criteria for the diagnosis of aneuploidy by analyzing the results of FISH test. Methods : From January, 1999 to May, 2006, 8,613 tests in amniotic fluids obtained from 7,893 pregnant women were performed by using FISH for prenatal diagnosis of trisomy 21, trisomy 18 and trisomy 13. The indications of chromosome study were a screen positive for Down syndrome or Edwards syndrome in maternal serum marker screening test and an advanced maternal age (${\geq}35$ years old). Results : We have the 8,502 informative results from 8,613 tests (98.7%) which is submitted our criteria and the sensitivity is 98.2%. Conclusion : FISH on uncultured amniocytes is a rapid, clinically useful tool for prenatal diagnosis, with informative specimens being highly accurate. But the limitation of FISH is both expensive and labor-intensive.

• Clinical and Experimental Pediatrics
• /
• v.46 no.8
• /
• pp.831-835
• /
• 2003

Holoprosencephaly of unknown definite causes, has been associated with several chromosome abnormalities involving the autosomes and the sex chromosomes. The most commonly reported associations include dup(3p), del(7q), deletions of chromosome 13, trisomy 13, trisomy 18, and triploidy. In previously reported cases in Korea, none were associated with chromosome 21 anomalies. In conclusion, we reported the first case of holoprosencephaly(semilobar type) associated with pure monosomy 21. We experienced a semilobar type holoprosencephaly with monosomy 21 in a neonate who had multiple congenital anomalies, including an abnormal face, a small thorax with widely spaced hypoplastic nipples and nail hypoplasia, lung hypoplasia with severe scoliosis and cardiac abnormalities. Chromosomal analysis revealed a 45, XY, -21.