TUBB1 mutation in children with congenital hypothyroidism and thyroid dysgenesis in Shandong, China / 中国当代儿科杂志

OBJECTIVE@#To study the types and characteristics of TUBB1 mutation in children with congenital hypothyroidism (CH) and thyroid dysgenesis (TD) in Shandong, China.@*METHODS@#Mutations of the whole coding region of the TUBB1 gene were analyzed for 289 children with CH and TD in Shandong. Whole-genome DNA was extracted from peripheral blood leukocytes. PCR multiplication was performed for the whole coding region of the TUBB1 gene. Sanger sequencing was performed for the PCR products, and a biological information analysis was performed.@*RESULTS@#Among the 289 children with CH and TD, 4 (1.4%) were found to have a c.952C>T(p.R318W) heterozygous mutation in the TUBB1 gene, resulting in the change of tryptophan into arginine at codon 318 of TUBB1 protein. This mutation was evaluated as "potentially pathogenic" based on the classification criteria and guidelines for genetic variation by American College of Medical Genetics and Genomics.@*CONCLUSIONS@#A novel mutation is detected in the exon of the TUBB1 gene in children with CH and TD in Shandong, suggesting that the TUBB1 gene may be a candidate pathogenic gene for CH children with TD.

DUOX2 mutations in children with congenital hypothyroidism / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the features of DUOX2 mutations and genotype-phenotype relationship in children with congenital hypothyroidism (CH), in order to provide evidence for gene diagnosis and gene treatment of CH.</p><p><b>METHODS</b>Blood samples were collected from 10 CH children with thyromegaly. Genomic DNA was extracted from peripheral blood leukocytes. All exons of DUOX2 gene were analyzed using PCR and direct sequencing.</p><p><b>RESULTS</b>G3632A mutation in the exon 28 of DUOX2 that may result in arginine to histidine substitution at codon 1211 was found in one patient. T2033C mutation in the exon 17 of DUOX2 that may result in histidine to arginine substitution at codon 678 was found in three patients. They were all heterozygous mutations.</p><p><b>CONCLUSIONS</b>Heterozygous mutations in DUOX2 may affect protein function and cause CH. The relationship between DUOX2 genotypes and clinical phenotypes is unclear and needs further studies.</p>

Effect of 5-aza-2'-deoxycytidine combined with trichostatin A on RPMI-8226 cell proliferation, apoptosis and DLC-1 gene expression / 中国实验血液学杂志

This study was aimed to investigate the effects of the DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-Aza-CdR) and histone deacetylase inhibitor trichostatin A (TSA) on DLC-1 gene transcription regulation and molecular biological behaviours in the human multiple myeloma RPMI-8226 cells. The cells were treated respectively with 5-Aza-CdR and TSA alone, or the both combination; the cell proliferation and apoptosis, DLC-1 expression, the protein expression of Ras homolog family member A (RhoA) and Ras-related C3 botulinum toxin substrate 1 (Rac1) were examined by CCK-8 method, RT-PCR and ELISA, respectively. The results showed that the 5-Aza-CdR and TSA had cell growth inhibitory and apoptosis-inducing effects in dose-dependent manner (P < 0.05). Compared with a single drug (5-Aza-CdR or TSA alone), the effects were significantly enhanced after treatment with the combination of 5-Aza-CdR and TSA (P < 0.05). DLC-1 was weakly expressed in the control group; the treatment with 5-Aza-CdR alone enhanced its re-expression dose-dependently (P < 0.05). Compared with 5-Aza-CdR alone, 5-Aza-CdR plus TSA enhanced DLC-1 re-expression significantly.Compared with the control, 5-Aza-CdR and TSA significantly decreased RhoA and Rac1 protein expression (P < 0.05). It is concluded that 5-Aza-CdR and TSA can effectively reverse DLC-1 expression of RPMI-8226 cells; TSA has a synergistic effect on its re-expression. 5-Aza-CdR and TSA have significant cell growth inhibitory and apoptosis-inducing effects on RPMI-8226 cells. These effects may be related to the inhibition of Rho/Rho kinase signalling pathway.

Family-based association study of a variable number of tandem repeat polymorphism of DAT1 gene with Tourette syndrome in a Chinese Han population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the association of a 40 bp variable number of tandem repeat (VNTR) polymorphism within 3 untranslated region of dopamine transporter gene (DAT1) with Tourette syndrome (TS) in a Chinese Han population.</p><p><b>METHODS</b>A total of 160 TS patients and their parents were recruited. The VNTR polymorphism was detected with polymerase chain reaction-VNTR analysis, and its association with TS and its subtypes were assessed through a family-based association study comprising transmission disequilibrium test (TDT) and haplotype relative risk (HRR) analysis.</p><p><b>RESULTS</b>The repeat numbers at the DAT1 40 bp locus were 11, 10, 9, 7.5 and 7 among the patients and their parents, with the most common type being a 10-repeat allele. No significant association was detected between the polymorphism and TS (TDT: X ² = 0.472, df = 1, P = 0.583; HRR: X ² = 0.313, P = 0.576, OR = 0.855, 95%CI: 0.493-1.481).</p><p><b>CONCLUSION</b>Our data suggested that the VNTR polymorphism of DAT1 gene is not associated with susceptibility to TS in Chinese Han population. However, our results are to be validated in larger sets of patients collected from other populations.</p>

DUOX2 gene mutation in patients with congenital goiter with hypothyroidism / 中华儿科杂志

<p><b>OBJECTIVE</b>To identify DUOX2 gene mutation in patients with congenital goiter with hypothyroidism.</p><p><b>METHOD</b>Five patients who had transit congenital hypothyroidism with goiter were enrolled. The exons of DUOX2 gene were amplified and sequenced.</p><p><b>RESULT</b>A heterozygous missense mutation C1329T in the exon 10 of the DUOX2 gene was found in one patient, predicted to result in a Tryptophan to Arginine substitution at codon 376. However no mutation was detected in the other patients.</p><p><b>CONCLUSION</b>p.Arg376Trp mutation in DUOX2 was found in newborns of congenital hypothyroidism. The alleles frequency of this mutation may contribute to the function loss of congenital hypothyroidism.</p>

EXT1 and EXT2 mutation identified by denaturing high performance liquid chromatograph in three families with hereditary multiple exostoses / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To develop a new denaturing high performance liquid chromatograph (DHPLC)-based method to screen patients with EXT gene mutation and to study the gene mutation in three families with multiple exostoses.</p><p><b>METHODS</b>All the exons of EXT gene, including the intro-exon boundaries, were amplified by PCR. Linkage analysis and DHPLC screening were carried out to identify the mutations. DNA sequencing was used to confirm the mutations.</p><p><b>RESULTS</b>Two known splice site mutations, IVS2+1 G to A and IVS7+1 G to T, and two SNPs have been detected in EXT2 or EXT1 gene.</p><p><b>CONCLUSION</b>The transversions of IVS2+1 G to A and IVS7+1 G to T in EXT2 gene are suggested to be the disease-causing mutations and the DHPLC is a high throughout, sensitive, simple, quick, economical method to screen gene mutation in hereditary multiple exostosis.</p>