In this study, biomarkers and transcriptional factor motifs were identified in order to investigate the etiology and phenotypic severity of Down syndrome. GSE 1281, GSE 1611, and GSE 5390 were downloaded from the gene expression ominibus (GEO). A robust multiarray analysis (RMA) algorithm was applied to detect differentially expressed genes (DEGs). In order to screen for biological pathways and to interrogate the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database, the database for annotation, visualization, and integrated discovery (DAVID) was used to carry out a gene ontology (GO) function enrichment for DEGs. Finally, a transcriptional regulatory network was constructed, and a hypergeometric distribution test was applied to select for significantly enriched transcriptional factor motifs. CBR1, DYRK1A, HMGN1, ITSN1, RCAN1, SON, TMEM50B, and TTC3 were each up-regulated two-fold in Down syndrome samples compared to normal samples; of these, SON and TTC3 were newly reported. CBR1, DYRK1A, HMGN1, ITSN1, RCAN1, SON, TMEM50B, and TTC3 were located on human chromosome 21 (mouse chromosome 16). The DEGs were significantly enriched in macromolecular complex subunit organization and focal adhesion pathways. Eleven significantly enriched transcription factor motifs (PAX5, EGR1, XBP1, SREBP1, OLF1, MZF1, NFY, NFKAPPAB, MYCMAX, NFE2, and RP58) were identified. The DEGs and transcription factor motifs identified in our study provide biomarkers for the understanding of Down syndrome pathogenesis and progression.

ABSTRACT. Congenital cataract is caused by reduced transparency of the lens resulting from metabolic disorders during the fetal period. The disease shows great heterogeneity both clinically and genetically. We identified a 4-generation ethnic Han Chinese family affected by autosomal dominant congenital perinuclear cataract. The patients underwent full clinical and ophthalmologic examinations to rule out any concomitant disorders. Blood samples were collected and genomic Novel CRYAA mutation underlying congenital cataract DNA was extracted. Potential mutations in the candidate gene alpha A crystallin (CRYAA) were screened. Prenatal diagnosis was then provided for a fetus of the affected proband by chorionic villus sampling. In all patients, DNA sequencing of the CRYAA gene revealed a novel 3-bp deletion mutation in exon 3 (c.246_248delCGC), which led to deletion of codon 117 encoding arginine (p.117delR) in the peptide chain. The same mutation was not found among unaffected and healthy individuals. Bioinformatic analysis revealed that although the c.246_248delCGC is an 'in-frame' mutation, removal of arginine resulted in a significant change in the protein structure. The fetus did not possess this mutation and was confirmed to be healthy at 1-year follow-up. A novel diseasecausing mutation, c.246_248delCGC (p.117delR), of the CRYAA gene has been identified in a Chinese family with autosomal-type perinuclear congenital cataracts. This is also the first report of prenatal diagnosis of this type of congenital cataract.

ABSTRACT. Isolated methylmalonic acidemia (MMA) is a genetically heterogeneous disorder caused mainly by deficiency of methylmalonyl-CoA mutase. In the present study, we analyzed MUT gene mutations in 3 Chinese couples with a birth history of isolated MMA. We also provided prenatal diagnoses for the detected mutation. Exons and exon-intron boundaries of the MUT gene were analyzed by polymerase chain reaction and direct sequencing. Prenatal genetic diagnoses were performed by chorionic villus sampling after the genotypes of parents were determined. Six heterozygous mutations in the MUT gene were identified in the 3 families, including c.1880A>G

We explored the feasibility of applying gene diagnosis in prenatal diagnosis by analysis of hypoxanthine-guanine phosphoribosyltransferase-1 (HPRT1) gene mutation in a Chinese Lesch-Nyhan family. A homozygous mutation of p.R170X (c.508C＞T) in HPRT1 gene was detected in the proband, and a heterozygous mutation of p.R170X was detected in his mother. This mutation failed to be found in the 50 unrelated healthy individuals. Prenatal diagnosis indicated that the foetus was male and also carried p.R170X (c.508C＞T) mutation, same as the proband. Parents of the foetus decided termination of pregnancy, and the result of gene analysis for the aborted tissue was consistent with that of prenatal diagnosis. We can see that Lesch-Nyhan syndrome (LNS) is caused by non-sense mutation p.R170X（c.508C＞T）in HPRT1 gene in this family. Prenatal gene diagnosis is a valid strategy to prevent LNS because it can avoid the birth of LNS foetuses.