Heterozygosity and repeat numbers of the selected STR markers in the tested Chinese Han population.

<p>*Expected PCR product sizes are predicted according to human genome hg19 assembly.</p><p>**Heterozygosity for DXS1053, DXS981, DXS6809, DXS1187 and DXS8377 was calculated using Female samples, while heterozygosity for X22, D21S11 and D13S305 was calculated using all tested samples.</p><p>Heterozygosity and repeat numbers of the selected STR markers in the tested Chinese Han population.</p

Graphic scheme of the chromosomal localization of the eight sex chromosomal markers used in the newly designed multiplex PCR assay.

<p>The markers were located according to Human Genome Browser – hg38 assembly.</p

Representative examples for a normal female (A), a normal male (B), a trisomy X (47, XXX) (C), a Klinefelter syndrome (47, XXY) (D), a Jacob’s syndrome (47, XYY) (E) and a Turner syndrome (45, X) (F) obtained through the 10-plex QF-PCR assay.

<p>The results are produced using the GeneMapper software, showing full ranges and all sizes of the detected peaks on the vertical and horizontal axes respectively for intuitive intra-sample visual comparison of the peaks. Fragment sizes are shown in bp on the horizontal axis. Arbitrary fluorescence units are shown on the vertical axis.</p

Establishment of a 10-Plex Quantitative Fluorescent-PCR Assay for Rapid Diagnosis of Sex Chromosome Aneuploidies

<div><p>Sex chromosome aneuploidies occur commonly in the general population, with an incidence of 1 in 400 newborns. However, no tests specifically targeting sex chromosomes have been carried out in prenatal diagnosis or newborn screening, resulting in late recognition of these diseases. In this study, a rapid diagnostic method for sex chromosome aneuploidies was established using Quantitative Fluorescent-PCR (QF-PCR). Ten markers were included in one multiplex QF-PCR assay, including two sex determination genes (AMXY and SRY), five X-linked short tandem repeats (STRs; DXS1053, DXS981, DXS6809, DXS1187, and DXS8377), one X/Y-common STR (X22), and two autosomal STRs (D13S305 and D21S11). Retrospective tests of 70 cases with known cytogenetic results indicated that the 10-plex QF-PCR assay could well determine sex chromosome copy numbers by both allelic peak numbers and a sex chromosome dosage calculation with the autosomal STRs as internal controls. Prospective comparison with cytogenetic karyotyping on 534 cases confirmed that the 10-plex QF-PCR assay could be well employed for sex chromosome aneuploidy diagnosis in at least the Chinese Han population. This is the first QF-PCR test for the diagnosis of sex chromosome aneuploidies in the Chinese population. This test is superior to previous designs by including up to 8 sex-linked markers covering different parts of sex chromosomes as well as employing internal controls for copy number dosage calculation in a single PCR reaction. Due to simple technique and data analysis, as well as easy implementation within routine clinical services, this method is of great clinical application value and could be widely applied.</p></div

Capillary electrophoresis results for three samples with sex chromosomal aneuploidies identified in the prospective examination, including (A) a suspected 23, X finally confirmed by karyotyping, (B) a case of triploidy ‘69, XXX’, and (C) a case of triploidy with an additional chromosome 21 (70, XXX,+21).

<p>Capillary electrophoresis results for three samples with sex chromosomal aneuploidies identified in the prospective examination, including (A) a suspected 23, X finally confirmed by karyotyping, (B) a case of triploidy ‘69, XXX’, and (C) a case of triploidy with an additional chromosome 21 (70, XXX,+21).</p