[Prenatal diagnosis and genetic analysis of a special case with complex structural rearrangements of chromosome 8].

OBJECTIVE: To present on a prenatally diagnosed case with complex structural rearrangements of chromosome 8. METHODS: Chromosome karyotyping, chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) were carried out for a fetus with increased nuchal thickness. RESULTS: The karyotype of the amniotic fluid sample showed extra materials on 8p. FISH revealed a centromeric signal at the terminal of 8p with absence of telomeric signal. CMA revealed partial deletion of 8p23.3 [(208049_2256732)×1], partial duplication of 8p23.3p23.2 [(2259519_3016818)×3], and partial duplication of 8q [8q11.1q12.2(45951900_60989083)×3]. CONCLUSION: The complex structural rearrangements of chromosome 8 in this case has differed from the commonly seen inv dup del(8p).

Convolutional Neural Network-Based Computer-Assisted Diagnosis of Hashimoto's Thyroiditis on Ultrasound.

PURPOSE: This study investigates the efficiency of deep learning models in the automated diagnosis of Hashimoto's thyroiditis (HT) using real-world ultrasound data from ultrasound examinations by computer-assisted diagnosis (CAD) with artificial intelligence. METHODS: We retrospectively collected ultrasound images from patients with and without HT from 2 hospitals in China between September 2008 and February 2018. Images were divided into a training set (80%) and a validation set (20%). We ensembled 9 convolutional neural networks (CNNs) as the final model (CAD-HT) for HT classification. The model's diagnostic performance was validated and compared to 2 hospital validation sets. We also compared the accuracy of CAD-HT against seniors/junior radiologists. Subgroup analysis of CAD-HT performance for different thyroid hormone levels (hyperthyroidism, hypothyroidism, and euthyroidism) was also evaluated. RESULTS: 39 280 ultrasound images from 21 118 patients were included in this study. The accuracy, sensitivity, and specificity of the HT-CAD model were 0.892, 0.890, and 0.895, respectively. HT-CAD performance between 2 hospitals was not significantly different. The HT-CAD model achieved a higher performance (P < 0.001) when compared to senior radiologists, with a nearly 9% accuracy improvement. HT-CAD had almost similar accuracy (range 0.87-0.894) for the 3 subgroups based on thyroid hormone level. CONCLUSION: The HT-CAD strategy based on CNN significantly improved the radiologists' diagnostic accuracy of HT. Our model demonstrates good performance and robustness in different hospitals and for different thyroid hormone levels.

Application of FF-QuantSC for the Precise Estimation of Fetal Fraction in Non-invasive Prenatal Testing in Two SRY-Translocation Cases.

Background: Non-invasive prenatal testing (NIPT) is a commonly employed clinical method to screen for fetal aneuploidy, while the Y chromosome-based NIPT method is regarded as the gold standard for the estimation of fetal fraction (FF) of male fetuses. However, when the fetus has a derivative Y chromosome thereby containing a partial Y chromosome, the Y chromosome-based NIPT method cannot accurately calculate FF. Therefore, alternative methods to precisely calculate FF are required. Methods: Two prenatal cases could not be detected effectively using the Y chromosome-based NIPT method because of low FF. According to the Y chromosome-based method, the FF of the fetuses were 1.730 ± 0.050% (average gestation week: 18+1) and 2.307 ± 0.191% (average gestation week: 20+0) for cases 1 and 2, respectively. Using various genetic diagnostic techniques, including the BoBs™ assay, karyotype analysis, improved nucleolus-organizing region (NOR)-banding analysis, Affymetrix CytoScan 750K Array, and fluorescence in situ hybridization (FISH) analysis, we determined the genetic defects of two fetuses with translocations of the SRY locus. Further, we reassessed the FF using FF-QuantSC and X chromosome-based methods. The distribution diagram of reads for chromosome Y was also analyzed. Results: The FF of the fetuses determined by FF-QuantSC were 10.330% (gestation week: 18+4) in case 1 and 9.470% (gestation week: 21+4) in case 2, while the FF of the fetuses determined using the X chromosome-based method were 8.889% (gestation week: 18+4) in case 1 and 2.296% (gestation week: 21+4) in case 2. Both the distribution diagrams of reads for chromosome Y of the two cases showed the deletion in the long arm of the Y chromosome. Conclusion: For repeatedly low FF samples detected using the Y chromosome-based NIPT method for a long gestational week, we believe that FF-QuantSC and distribution diagrams of reads could be used as a supplement to NIPT, especially for rare cases of sex reversal caused by SRY translocation.

[Genetic analysis of a 45,X male fetus].

OBJECTIVE: To analyze the prenatal diagnosis procedure for a 45,X male fetus. METHODS: A 31-year-old women underwent amniocentesis due to a moderate risk of trisomy 21. The fetal cells were subjected to chromosomal karyotyping, BACs-on-BeadsTM (BoBs) assay, chromosomal microarray analysis and fluorescence in situ hybridization. RESULTS: Combined analyses revealed that the whole of Yp has translocated to 21p, which yielded a fetal karyotype of 45,X,dic(Y;21)(q11;p11).ishdic(Y;21)(SRY+,CEPY+;CEP21+). CONCLUSION: BoBs and modified N-banding method are helpful for the diagnosis of 45,X male fetus with Yp translocation.

[Application of BACs-on-BeadsTM in prenatal diagnosis].

OBJECTIVE: To explore the value of BACs-on-BeadsTM (BoBs) for the practice of prenatal diagnosis. METHODS: The results of chromosomal karyotyping and BoBs of 1773 prenatal samples were compared. Microdeletions and microduplications detected by BoBs were subjected to chromosome microarray analysis (CMA) with informed consent from patients. RESULTS: BoBs has detected 46 cases of common aneuploidies involving chromosomes 13, 18, and 21, and 16 cases involving X and Y chromosomes. For 4 fetuses with normal results by BoBs, karyotyping analysis of amniotic fluid sample suggested low percentage mosaicisms (< 20%). BoBs has detected none of the 9 common microdeletions, but 14 male fetuses with Xp22 microdeletions and 5 with other microdeletions/microduplications. In 10 cases, the couples had chosen CMA verification, and the results were all consistent. CONCLUSION: As a rapid diagnostic technique, BoBs has a high accuracy for common aneuploidies, and is capable of discovering certain chromosome microdeletions and microduplications. The difficulty lies in the inability to detect low proportion mosaicisms and the consultation following detection for male fetuses carrying Xp22 microdeletions.

[Study of two cases of prenatally detected small supernumerary marker chromosomes].

OBJECTIVE: To determine the origin of two prenatally detected small supernumerary marker chromosomes (sSMCs). METHODS: The sSMCs were analyzed with combined G-banding, C-banding, fluorescence in situ hybridization (FISH), and single nucleotide polymorphisms array (SNP-array) techniques. RESULTS: In case 1, G-banding analysis has identified a 47,XY,+mar karyotype. Affymetrix CytoScan 750K Array scan has suggested arr 15q11.2q12(22 770 421-26 604 587)?, while FISH analysis suggested 47,XN,+mar.ish i(15)(q12)(D15Z1+,SNRPN++,PML-). In case 2, G-banding analysis has suggested 46,X,+mar/46,XY, FISH analysis showed two SRY hybridization signals, indicating 46,X,i(Y)(p10)/46,XY. CONCLUSION: Multiple techniques needed be applied for verification of the origin of sSMCs identified in prenatal diagnosis.