Application of fluorescence in situ hybridization to prenatal diagnosis of aneuploidy in 110 uncultured amniotic fluid samples / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To optimize the prenatal diagnosis platform by using domestically made fluorescence in situ hybridization(FISH) kit and to explore the clinical application of FISH to rapid prenatal diagnosis of a wide range of chromosomal abnormalities.</p><p><b>METHODS</b>Amniotic fluid samples from 110 pregnant women were studied with the rapid prenatal diagnosis method of FISH and the conventional cell culture method of karyotyping, the results from both methods were compared.</p><p><b>RESULTS</b>Four cases of trisomy 21, 1 case of trisomy 18, 58 cases of 46, XX, and 47 cases of 46, XY were detected by FISH in the 110 amniotic fluid samples. It is concordant with the results from conventional karyotype analysis. The concordance rate is 100%.</p><p><b>CONCLUSION</b>Domestically made FISH kit can be used to rapidly and accurately detect the most common chromosome aneuploidies by using less sample volume while the price is relatively low. FISH can be a reliable and rapid prenatal diagnostic tool as an adjunct to classical cytogenetic study. It can be used for rapid and accurate prenatal diagnosis of women with high risk of maternal serum screening.</p>

Application of spectral karyotyping in diagnosis of complex chromosome aberration / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the value of spectral karyotyping (SKY) to identify the complex chromosome aberration.</p><p><b>METHODS</b>Four cases were selected that can not be identified by standard cytogenetic techniques. The chromosome specimens were detected by the routine SKY method, and the results were analyzed by the SKY View software.</p><p><b>RESULTS</b>By using SKY a case of complex chromosome rearrangements and two cases of chromosome duplication were identified. However it could not identify the chromosome inversion and the breakpoint of chromosome aberration.</p><p><b>CONCLUSION</b>SKY may be a valuable tool in identification of complex chromosome translocation, rearrangement, minute aberration and unknown derivative chromosomes. Though SKY can not replace the standard cytogenetic techniques, but it will be the benefit supplementary.</p>

HLA-B gene polymorphism detected by high-resolution sequence-based typing in Guangdong Han populations / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the genetic polymorphism of HLA-B locus in Guangdong Han population and compare the characteristic of the allele frequency distribution with that in other populations.</p><p><b>METHODS</b>A total of 562 cord blood samples from Guangzhou Cord Blood Bank were analyzed by sequence-based typing. Then the sequences encompassing exons 2, 3, and 4 for HLA-B gene were analyzed by direct sequencing of PCR products. The allele frequency distribution of HLA-B in this population was compared with that in other populations.</p><p><b>RESULTS</b>A total of 59 different HLA-B alleles were detected, and among them were 6 HLA-B alleles with frequencies higher than 5%: HLA-B*4601 (14.5%), HLA-B*400101 (14.4%), HLA-B*1502 (11.5%), HLA-B*1301 (8.6%), HLA-B*5801 (8.1%) and HLA-B*380201 (6.4%); the total frequency of these six alleles was 63.5%. At the same time, there were 30 kinds of HLA-B allele with frequencies lower than 0.5%; the total frequency of these alleles was 4.9%. Maximum variation at HLA-B was seen in the HLA-B*15 allele family (nine alleles). Comparison of the HLA-B frequencies in different populations showed a close relationship of Guandong Han population with the Chinese populations from Hong Kong and Singapore, respectively.</p><p><b>CONCLUSION</b>The results have shown the characteristic of HLA-B distribution and provided more accurate genotypic data that may serve as normal reference value for the Han population in Guangdong, China.</p>