Prenatal diagnosis of 15q11.2 microdeletion fetuses in Eastern China: 21 case series and literature review.

OBJECTIVE: 15q11.2 microdeletion can lead to syndromes affecting the nervous system. However, 15q11.2 microdeletion has large phenotypic differences and incomplete penetrance, which brings challenges to prenatal diagnosis. We reported 21 cases of 15q11.2 microdeletion fetuses in Eastern China and reviewed literature on the prenatal clinical characteristics related to the deletion variants to provide a basis for prenatal genetic counseling. METHODS: The clinical data of 21 cases of 15q11.2 microdeletion fetuses collected from June 2018 to September 2021 were retrospectively analyzed, and chromosomal microarray analysis was performed. The reported prenatal clinical features of 15q11.2 microdeletion fetuses were reviewed and summarized. A meta-analysis of 20 studies was performed to test heterogeneity, data integration, and sensitivity on the correlation between 15q11.2 microdeletion and neuropsychiatric diseases. RESULTS: The median age of the women was 29.5 years. The median gestational age at interventional examination was 24 weeks. All fetuses showed deletion variants of the 15q11.2 fragment, and the median deletion range was approximately 0.48 MB. Ultrasound of five cases showed no abnormalities; however, four of them showed a high risk of Down's syndrome (risk values were 1/184, 1/128, 1/47, and 1/54, respectively). The remaining 16 fetuses showed congenital heart disease (7/16), elevated nuchal translucency (5/16), abnormal brain structure (2/16) and renal disease (2/16). In a literature review of 82 prenatal cases, 44% (36/82) had abnormal ultrasound features, 31% (11/36) showed abnormal nuchal translucency, approximately 28% (10/36) showed abnormal cardiac structure, and 14% (5/36) had brain structural abnormalities. The meta-analysis revealed that the frequency of the 15q11.2 microdeletion mutation in patients with schizophrenia and epilepsy was significantly higher (odds ratio 2.04, 95% confidence interval: 1.78-2.33, p < 0.00001; odds ratio 5.23, 95% confidence interval: 2.83-9.67, p < 0.00001) than that in normal individuals. CONCLUSION: More than half of the 15q11.2 microdeletion cases presented no abnormalities in prenatal ultrasound examination. The cases with ultrasound features mainly showed isolated malformations such as elevated nuchal translucency, congenital heart disease, and brain structural abnormalities. Postpartum 15q11.2 microdeletion patients are at an increased risk of suffering from schizophrenia, epilepsy, and other neurological and mental diseases from 15q11.2 microdeletion. Therefore, prenatal diagnosis of 15q11.2 microdeletion not only depends on molecular diagnostic techniques but also requires cautious genetic counseling.

Association of two SNPs in 3'UTR of ETS1 gene with systemic lupus erythematosus in a northern Chinese Han population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the association between 2 single nucleotide polymorphisms (SNPs) of ETS1 gene and susceptibility to systemic lupus erythematosus (SLE) in a northern Chinese Han population.</p><p><b>METHODS</b>Two SNPs within the ETS1 gene mapped to 11q23 were selected based on HapMap data. Genotyping was conducted with Taqman method in 231 patients with SLE and 474 healthy controls from Qilu Hospital, Shandong and analyzed with PLINK1.07 software. Haplotypes were analyzed with SHEsis software.</p><p><b>RESULTS</b>A statistically significant difference was detected in the distribution of rs1128334 and rs4937333 genotypes between the two groups (all P< 0.01). For rs1128334, the frequency of the minor allele was 0.291 and 0.428 in controls and cases, respectively. For rs4937333, the minor allele frequency was 0.381 and 0.476 in controls and cases respectively. An A-C haplotype was found to be strongly associated with increased risk for SLE, while another haplotype G-C may reduce this risk.</p><p><b>CONCLUSION</b>Our study has suggested that rs1128334 and rs4937333 are strongly associated with the risk for SLE in northern Chinese Han population.</p>

Analysis on genetic polymorphism of 5 STR loci selected from X chromosome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To select short tandem repeats(STR) from X chromosome.</p><p><b>METHODS</b>STR is a universal genetic marker that has changeable polymorphism and stable heredity in human genome. It is a specific DNA segment composed of 2-6 base pairs as its core sequence. It is an ideal DNA marker used in linkage analysis and gene mapping. In this study, 8 short tandem repeats were selected from two genomic clones on X chromosome by using BCM Search Launcher. Primers amplifying the STR loci were designed by using Primer 3.0 according to the unique sequence flanking the STRs. Polymorphisms of the short tandem repeats in Chinese population were evaluated by PCR amplification and PAGE.</p><p><b>RESULTS</b>Five of these STRs were polymorphic. Chi-square test indicated that the distribution of genotypes agreed with Hardy-Weinberg equilibrium (P>0.05).</p><p><b>CONCLUSION</b>Five polymorphic short tandem repeats have been identified on chromosome X and will be useful for linkage analysis and gene mapping.</p>

Fine mapping of Smith-Fineman-Myers syndrome and exclusion of GPC3, GPCR2 MST4 and GLUD2 as candidate genes / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>Smith-Fineman-Myers syndrome (SFMS) is an X-linked mental retardation syndrome. The authors had ascertained a large Chinese family with SFMS from Shandong and had mapped the disease locus to an interval of 19.8 Mb on Xq25 flanked by markers DXS8064 and DXS8050. Further investigation suggested that SFMS exhibited locus heterogeneity. In this study for facilitating the identification of the gene responsible for SFMS, the additional markers were analyzed to narrow down the candidate region, and four candidate genes (GPC3, MST4,GPCR2 and GLUD2) were chosen and screened for disease-causing mutation.</p><p><b>METHODS</b>PCR and denaturing polyacrylamide gel electrophoresis were used to genotype 13 new polymorphic markers distributed within the candidate region. Mutation detection was accomplished by sequencing the exons and intron-exon junctions of the candidate genes.</p><p><b>RESULTS</b>By analyzing 13 additional polymorphic markers, SFMS candidate region can be reduced to an interval of 10.18 Mb bounded by XSTR3 and XSTR4, and no disease-causing mutation was identified in the coding regions of four candidate genes.</p><p><b>CONCLUSION</b>GPCR2 GPC3, MST4 and GLUD2 were excluded as pathogenic genes for SFMS. The refined SFMS locus will assist in the identification and characterization of other candidate genes for SFMS.</p>

Application of homozygosity mapping to the fine mapping of the osteoporosis-pseudoglioma syndrome locus / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To evaluate the role of homozygosity mapping in the fine mapping of the genes responsible for the rare autosomal recessive diseases.</p><p><b>METHODS</b>Polymerase chain reaction-single sequence length polymorphism was used to genotype the family members from 8 families with osteoporosis-pseudoglioma syndrome(OPS) for 14 polymorphic loci within candidate region. The OPS candidate region was narrowed by searching for homozygous region in affected.</p><p><b>RESULTS</b>The OPS candidate region was narrowed to a 1 cM interval between D11S1296 and D11S4136.</p><p><b>CONCLUSION</b>Homozygosity mapping is a powerful method for mapping and narrowing the candidate region of the genes responsible for the rare autosomal recessive diseases.</p>

THE EFFECT OF TRICHODERMA HARZIAIARUM ON THE RICE NITRATE REDUCTASE ACTIVITY AND N, P, K CONTENT / 微生物学通报

The muttagenic H-13 strain which was injected by ionic beam and screened from Trichoderma hamzlaiarum, can promote the growth of rice remarkably. In the experiment, we use zymolytic liquid of H-13 strain sprinkle on the seedling of rice, and determine nitrate reductase activity and N, P, K content. The results suggest that the effect of promoting plant growth of the strain has a relation to the enhance of nitrate reductase activity and the increase of N, P and K absorption.