Objective To determine the value of spectral karyotyping(SKY)in identification of the marker chromosome.Methods Selected six cases that could not be identified in clinic were studied,using samples of peripheral blood from four cases,and samples of amonic fluid and fetal cord blood for prenatal diagnosis in two cases were investigated.All cases were analyzed with the routine SKY method.and the results with the SKY View software.The SKY results were identified by using fluorescence in situ hybridization(FISH).And C-banding technique was used to help diagnose the heterochromatin.Results SKY wag successfully performed on all of 6 cases.The origin of all marker chromosomes was identified by SKY.Except case No.4,the others were confirmed by FISH.It helped determine the pregnancy outcome in two cases of prenatal diagnosis:one case of genetic marker chromosome continued the pregnancy,and another case of de novo marker chromosome was terminated of the pregnancy.Conclusion SKY may be a vahable tool to diagnose the marker chromosome with rapidness,direct-viewing and sensitiveness.It can be used to assess the prognosis and the pregnancy outcome.

Objective To investigate the relationship between spontaneous miscarriage and embryonic chromosome abnormalities,and to evaluate the clinical application of karyotype analysis by chorionic villus cell culture. Methods The chorionic villus karyotype of 1983 cases of miscarriage from January 2010 to July 2016 in Guangzhou Women and Children′ s Mecical Center were analyzed retrospectively. The miscarried chorionic villi were obtained by curettage under sterilized condition. The chromosome specimens were prepared after chorionic villus cell culture. Karyotype analysis was performed by G-banding technique. Results In the 1983 samples, successful karyotype analysis was performed in 1770 cases, with the successful rate of 89.98%. Chromosomal abnormalities were found in 1038 cases (58.64%,1038/1770). Chromosomal structural abnormalities were found in 37 cases. The numeral abnormalities were more common than structural abnormalities, and most of the numeral abnormalities were aneupoidies. In turn, they were trisomy 16, 45,X, trisomy 22, trisomy 2, trisomy 21, trisomy 15. The most common structural abnormality was balanced translocation, including Robersonian translocation. Female embryoes accounted for 61.02%(1080/1770) miscarriages and for 57.4%(596/1770) of chromosomal abnormalities, while male embroyes acoounted for 61.02%(1080/1770),57.4%(596/1770)respectively. The proportion of female embryoes was higher than male embryoes. The median age of the patients was 30 years old(16-46 years old). As the maternal age increased, the proportion chromosomal abnormalities increased. The incidence of chromosomal abnormalities in the advanced age group (≥35 years) was 68.38%(240/351), which was significantly higher than that in the younger group (56.24% ,798/1419; χ2=17.10, P<0.01). Conclusions Embryonic chromosomal abnormalities are the most common cause of early spontaneous miscarriage. The abnormalities centralize in some karyotypes. There is certain relationship between maternal age and the incidence of miscarriage, as well as the embryonic gender. Chorionic villus cell culture and karyotype analysis are helpful in finding the cause of miscarriage and counsel the patients.

OBJECTIVETo evaluate the method of array-based comparative genomic hybridization (array-CGH) in identifying unbalanced chromosome aberrations.

METHODSFour cases that could not be diagnosed by conventional cytogenetic technique were selected to undergo array-CGH analysis. DNA samples were extracted and hybridized with the Affymetrix SNP 6.0 arrays using Human Mapping SNP6.0 assay kit following the manufacturer's standard protocol. The data were analyzed by two professional software packages, GCOS and Genotyping Console.

RESULTSBy using array-CGH technique, all the four cases were diagnosed precisely through identifying two duplications and two complex derivative chromosomes.

CONCLUSIONArray-CGH is an effective method for whole-genome identification of unbalanced chromosomal aberrations with high sensitivity and specificity. It has a great value to investigate the correlations between genotype and phenotype in clinical service, especially in prenatal diagnosis.

Adolescent ; Adult ; Cells ; cytology ; Child, Preschool ; Chromosome Aberrations ; Comparative Genomic Hybridization ; methods ; Genetic Diseases, Inborn ; diagnosis ; genetics ; Humans ; Infant ; Male ; Young Adult