Down syndrome

Identification of altered pathways in Down syndrome-associated congenital heart defects using an individualized pathway aberrance score

Y. Q. Chen, Li, T., Guo, W. Y., Su, F. J., Zhang, Y. X., Chen, Y. Q., Li, T., Guo, W. Y., Su, F. J., Zhang, Y. X., Chen, Y. Q., Li, T., Guo, W. Y., Su, F. J., and Zhang, Y. X., Identification of altered pathways in Down syndrome-associated congenital heart defects using an individualized pathway aberrance score, vol. 15, p. -, 2016.

The aim of this study was to identify disrupted pathways related to Down syndrome (DS), and DS-associated congenital heart defects (DS-CHD). The gene expression profile and pathway data of 10 human DS patients and 5 control samples in E-GEOD-1789 were recruited and analyzed by the individualized pathway aberrance score (iPAS) method, consisting of the data processing, gene-level statistics, pathway-level statistics, and significant measurement steps. The pre-processing step identified 12,493 genes and 1022 pathways (4269 genes).

Inheritance of balanced translocation t(17; 22) from a Down syndrome mother to a phenotypically normal daughter

X. Y. Liu, Jiang, Y. T., Wang, R. X., Luo, L. L., Liu, Y. H., and Liu, R. Z., Inheritance of balanced translocation t(17; 22) from a Down syndrome mother to a phenotypically normal daughter, vol. 14, pp. 10267-10272, 2015.

We report that a 30-year-old woman with mental retardation was referred for prenatal diagnoses during pregnancy. An ultrasound scan showed that the heart structure and function of the fetus were normal. Cytogenetic analysis showed that the female karyotype was 47,XX, t(17; 22) (q21; q11), +21. The woman’s husband had a normal male karyotype and was phenotypically normal. During this first pregnancy, an amniocentesis, which was done at 19 weeks, revealed that the fetal karyotype was 46,XX, t(17; 22) (q21; q11).

Genetic analysis of STR markers on chromosome 21 in a Han population from southeast China

Y. N. Zhu, Lu, S. M., Wang, M., Shen, F. X., Chen, Y., and Hu, J. J., Genetic analysis of STR markers on chromosome 21 in a Han population from southeast China, vol. 14, pp. 1718-1725, 2015.

Short tandem repeats (STRs) are highly polymorphic sequences and have been extensively used as genetic markers in mapping studies, disease diagnosis, and human identity testing. In this study, 11 STR markers on chromosome 21, including D21S1432, D21S11, D21S1246, D21S1412, D21S1437, D21S1442, D21S2039, D21S1270, D21S1435, D21S1409, and D21S1446, were analyzed in 740 unrelated Han individuals from southeast China. A total of 132 alleles, ranging from 7-21 for each locus, were named according to the guidelines of the International Society for Forensic Haemogenetics.

Combined folate gene MTHFD and TC polymorphisms as maternal risk factors for Down syndrome in China

Y. P. Liao, Zhang, D., Zhou, W., Meng, F. M., Bao, M. S., Xiang, P., and Liu, C. Q., Combined folate gene MTHFD and TC polymorphisms as maternal risk factors for Down syndrome in China, vol. 13, pp. 1764-1773, 2014.

We examined whether polymorphisms in the methylenetetrahydrofolate dehydrogenase (MTHFD) and transcobalamin (TC) genes, which are involved in folate metabolism, affect maternal risk for Down syndrome. We investigated 76 Down syndrome mothers and 115 control mothers from Bengbu, China. Genomic DNA was isolated from the peripheral lymphocytes. Polymerase chain reaction and restriction fragment length polymorphism were used to examine the polymorphisms of MTHFD G1958A and TC C776G.

Retrospective analysis of live birth prevalence of children with Down syndrome in Denizli, Turkey

I. Acikbas, Tomatir, A. G., Akdag, B., and Köksal, A., Retrospective analysis of live birth prevalence of children with Down syndrome in Denizli, Turkey, vol. 11, pp. 4640-4645, 2012.

Down syndrome (DS) is the most frequent chromosome abnormality among live births. Its prevalence increases with maternal age, and can be diagnosed by antenatal screening. We examined prevalence variations of DS in Denizli, Turkey, through a retrospective study. Sixteen years of survey data were retrieved from the two main state hospital registries from records between 1994 and 2010. We identified 113 DS live births in Denizli for 16 years. The prevalence of DS was 9.07 per 10,000 live births before the year 2000 and 9.90 after 2000. The prevalence did not change significantly.

Analysis of GATA1 mutations and leukemogenesis in newborns with Down syndrome

L. B. Queiroz, Lima, B. D., Mazzeu, J. F., Camargo, R., Córdoba, M. S., Magalhães, I. Q., Martins-de-Sá, C., and Ferrari, I., Analysis of GATA1 mutations and leukemogenesis in newborns with Down syndrome, vol. 12, pp. 4630-4638, 2013.

It has been reported that patients with Down syndrome (DS) frequently develop transient myeloproliferative disorder (TMD) and less commonly myeloid leukemia in DS (ML-DS). We examined the pathogenetic relationship of these conditions with somatic mutations of the GATA1 gene in children with both TMD and ML-DS.

Genetic polymorphisms involved in folate metabolism and elevated plasma concentrations of homocysteine: maternal risk factors for Down syndrome in Brazil

J. M. Biselli, Goloni-Bertollo, E. M., Zampieri, B. L., Haddad, R., Eberlin, M. N., and Pavarino-Bertelli, E. C., Genetic polymorphisms involved in folate metabolism and elevated plasma concentrations of homocysteine: maternal risk factors for Down syndrome in Brazil, vol. 7, pp. 33-42, 2008.

The aim of the present study was to investigate the effect of polymorphisms C677T and A1298C in the methylenetetrahydrofolate reductase (MTHFR) gene, A2756G in methionine synthase reductase (MTR) gene and A80G in reduced folate carrier 1 (RFC1) gene, and plasma homocysteine (Hcy), on the maternal risk for Down syndrome (DS). Seventy-two DS mothers and 194 mothers who had no children with DS were evaluated.

Buccal micronucleus frequency is associated with age in Down syndrome

F. L. S. Ferreira, Prá, D., Martino-Roth, M. G., and Garcias, G. L., Buccal micronucleus frequency is associated with age in Down syndrome, vol. 8, pp. 1231-1237, 2009.

Down syndrome has been linked to premature aging and genomic instability. We examined the frequency of micronucleus (MN) and binucleated cells in the oral mucosa of Down syndrome patients and healthy controls matched by age and gender, addressing the effect of age and family income. Down syndrome individuals had an increased number of MN (14.30 ± 9.35 vs 4.03 ± 1.71; P 0.001) and binucleated cells (0.97 ± 1.3 vs 0.33 ± 0.66; P 0.05) per 2000 cells.

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