Genetic features of a case with mosaic ring chromosome 4 and a review of the literature / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis, clinical phenotype and pathogenesis for a child with mosaicism ring chromosome 4.@*METHODS@#Clinical data of the child was collected. Peripheral blood chromosomal karyotype G banding analysis, chromosomal microarray analysis (CMA), fluorescence in situ hybridization (FISH) were carried out for the child, in addition with a review of the literature.@*RESULTS@#The child was born full-term with low birth weight, facial dysmorphism, patent ductus arteriosus and ventricular septal defect. His karyotype was determined as mos46,XY,r(4)(p16.3q35.2)[259]/45,XY,-4[25]/47,XY,r(4)(p16.3q35.2), +r(4)(p16.3q35.2)[8]/46,XY,der(4)del(4)(p16.3)inv(4)(p16.3q31.1)[6]/46,XY,dic?r(4;4)(p16.3q35.2;p16.3q35.2)[4]/48,XY,r(4)(p16.3q35.2),+r(4)(p16.3q35.2)×2[3]/46,XY,r(4)(p1?q2?)[2]; CMA result was arr[GRCH37]4p16.3(68 345-2 981 614)×1; FISH result was 45,XY,-4[12]/45,XY,-4×2,+mar1.ish r1(4)(WHS-,D4Z1+)[1]/ 46,XY,-4,+mar1.ishr1(4)(WHS-,D4Z1+)[73]/46,XY,-4,+mar2.ishr2(4)(WHS-,D4Z1++)[1]/47,XY,-4,+mar1×2.ishr1(4) (WHS-, D4Z1+)×2[4]/46,XY,del(4)(p16.3).ish del(4)(p16.3)(WHS-,D4Z1+)[9].@*CONCLUSION@#In this case, the ring chromosome 4 as a de novo variant has produced a number of cell lines during embryonic development and given rise to mosaicism. The clinical phenotype of ring chromosome 4 is variable. The instability of the ring chromosome itself, presence of mosaicism, chromosome breakpoint and range of deletion and/or duplication may all affect the ultimate phenotype.

Result of prenatal diagnosis for 151 high-risk women by noninvasive prenatal screening based on high-throughput sequencing / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the value of combined fetal karyotyping and chromosomal microarray analysis (CMA) for the verification of high-risk pregnancy signaled by noninvasive prenatal screening (NIPS) based on high-throughput sequencing.</p><p><b>METHODS</b>One hundred and fifty-one pregnant women with high risks for aneuploidies of chromosomes 13, 18, 21, X and Y or pathological copy number variations (CNVs) by NIPS were subjected to amniocytic karyotyping and CMA analysis.</p><p><b>RESULTS</b>One hundred and forty-two women were found to have a high risk for fetal chromosomal aneuploidies, which included 83 cases of trisomy 21, 17 cases of trisomy 18, 2 cases of trisomy 13, and 40 cases of sex chromosome aneuploidies. Amniocytic karyotyping and CMA analysis has confirmed 81 cases of trisomy 21, 15 cases of trisomy 18, 10 cases of 47,XXY, 4 cases of 47,XXX, 2 cases of 47,XYY and 1 case of 46,X,del(X)(q26.1). Two trisomy 21, two trisomy 18, 2 trisomy 13, and 23 cases of sex chromosomal aneuploidies were verified as false positives. For 9 women with pathological fetal CNVs detected by NIPS, combined fetal karyotyping and CMA has confirmed 1 case of chromosome 13 microdeletion, 1 case of chromosome 18 microduplication, and 1 case of chromosome 18 deletion. For a case with 30 Mb duplication of chromosome 2 and 25 Mb duplication of chromosome 8, CMA analysis had no positive finding, while fetal umbilical cord blood karyotyping has yielded a 46,XX,dup(2)(p23.1p25.3)[13]/46,XX[87] karyotype. The remaining 5 cases were confirmed as false positive results.</p><p><b>CONCLUSION</b>Combined fetal karyotyping and CMA has provided a powerful tool for verifying high-risk fetuses signaled by NIPS.</p>

Relationship between the expression of Dishevelled2 and Vangl2 and the embryonic neural tube defects induced by excessive retinoic acid in Kunming mice / 解剖学报

ObjectiveTo explore the relationship between the expression of Dishevelled2 and Vangl2 and the embryonic neural tube defects (NTDs) induced by all-trans retinoic acid (RA)in Kunming mouse. Methods Fifty pregnant mice were randomly divided into control and RA-treated groups.RA-treated mice were fed with 30mg/kg RA dissolved with peanut oil on embryo 7.75 days, while the mice of control group were administrated with an equal volume of peanut oil on the same time. Then all the embryos were sampled from pregnant mice at the 4th, 18th, 42nd, 66th and 90th hour after treatment. In situ hybridization and immunohistochemical staining technique were used to detect the expression of Dishevelled2 and Vangl2 in embryonic neural tube. Results The two proteins both existed in the epithelial tissue of the mouse embryonic neural tube and displayed different expression modes at various developmental stages.Compared with the control group, the RA treated group showed a significant decrease (P≤0.05) at the 18th and 42nd hour and a significant increase (P≤0.05) at the 66th hour in Dishevelled2 protein after maternal treatment, and no significant difference was found at the 90th hour. Compared with the control group, the Vangl2 mRNA expression in the RA treated group displayed a significant decrease (P≤0.05) at the 4th and 18th hour and a significant increase (P≤0.05) at the 66th hour after RA treatment, and no difference was found at the 42nd hour. Compared with the control group, the expression of Vangl2 protein in the RA treated group decreased (P≤0.05) at the 18th and 42nd hour, and increased (P≤0.05) at the 90th hour after RA treatment, no difference was found at the 66th hour. Conclusion Excessive RA may interfere with the normal embryonic neural tube closure by regulating the expression of Dishevelled2 and Vangl2.