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Background DNA methylation is a crucial epigenetic modification of the genome which is involved in embryonic development, transcription, chromatin structure, X chromosome inactivation, genomic imprinting and chromosome stability. Consistent with these important roles, DNA methylation has been demonstrated to be required for vertebrate early embryogenesis and essential for regulating temporal and spatial expression of genes controlling cell fate and differentiation. Further studies have shown that abnormal DNA methylation is associated with human diseases including the embryonic development diseases. We attempt to study the DNA methylation status of CpG islands in fetus related to fetus growth and development. Methods GeneChip® Human Tiling 2.0R Array set is used for analysis of methylated DNA in a whole-genome wide in 8 pairs amniotic fluid and maternal blood DNA samples. Results We found 1 fetus hypermethylation DNA markers and 4 fetus hypomethylation DNA markers though a Genome-wide analysis. These DNA markers all found to be associated with the critical genes for fetus growth and development (SH2D3C gene, EML3 gene, TRIM71 gene, HOXA3 gene and HOXA5 gene). Conclusions These genes can be used as a biomarker for association studying of embryonic development, pathological pregnancy and so on. The present study has provided new and fundamental insights into the roles that DNA methylation has in embryonic development and in the pathological pregnancy. [ABSTRACT FROM AUTHOR]

The discovery of cell‑free DNA fetal (cff DNA) in maternal plasma during pregnancy provides a novel perspective for the development of non‑invasive prenatal diagnosis (NIPD). Against the background of maternal DNA, the use of the relatively low concentration of cff DNA is limited in NIPD. Therefore, in order to overcome the complication of the background of maternal DNA and expand the scope of cff DNA application in clinical practice, it is necessary to identify novel universal fetal‑specific DNA markers. The GeneChip Human Promoter 1.0R Array set was used in the present study to analyze the methylation status of 12 placental tissue and maternal peripheral blood whole‑genome DNA samples. In total, 5 fetus differential hypermethylation regions and 6 fetus differential hypomethylation regions were identified. In order to verify the 11 selected methylation regions and detect the differential CpG sites in these regions, a bisulfate direct sequencing strategy was used. In total, 87 fetal differential methylation CpG sites were identified from 123 CpG sites. The detection of fetal differential methylation DNA regions and CpG sites may be instrumental in the development of efficient NIPD and in the expansion of its application in other disorders. [ABSTRACT FROM AUTHOR]

Background: Chromosomal abnormalities that result in genomic imbalances are main causes of congenital and developmental anomalies including intellectual disability and multiple congenital malformations. In this report we describe four patients from three families with imbalanced translocations. Only a small percentage of imbalanced translocation individuals can be born to live, most of them were aborted in embryonic period. It is of great significances to precisely analysis the chromosome variation to study the relationship between genotype and phenotype. Results: Four patients showed common clinical manifestations including delayed growth, intellectual disability, language barrier and facial dysmorphisms. In addition to the above features, lower limbs dysplasia and both foot eversion were found in patient 1, brachydactylic hand, cerebellar ataxia and congenital heart defects were also found in patient 4. Conventional karyotype analysis revealed abnormal karyotypes 46, XX, der (6) t (6: 10) (p23; q24), 46, XX, der (20) t (3; 20) (p23; p13) and 46, XX, der (22) t (3; 22) (q27; q13.3) in the four patients, respectively. Array-CGH analyses confirmed 23.6 Mb duplication on 10q25.1-q26.3 and 0.9 Mb deletions on 6p25.3, 19.9 Mb duplication on 3p24.3-p26.3 and 0.25 Mb deletion on 20p13 and 12.5 Mb duplication on 3q27.2-q29 and 1.9 Mb deletions on 22q13.2-q13.33 in the four patients, respectively. Conclusion: Parents with balanced translocation are passed the imbalanced chromosome to patient, and the partial monosomy and partial trisomy lead to multiple congenital malformations of four patients. [ABSTRACT FROM AUTHOR]