Low Frequency of MKRN3 Mutations in Central Precocious Puberty Among Korean Girls

Mutations of MKRN3, the gene encoding makorin RING-finger protein 3, lead to central precocious puberty (CPP). The aim of this study was to investigate mutations of the MKRN3 gene in Korean girls with CPP. Two hundred-sixty Korean girls with idiopathic CPP were included. Auxological and endocrine parameters were measured, and the entire MKRN3 gene was directly sequenced. MKRN3 gene analysis revealed one novel nonsense mutation (p.Gln281 *) and 6 missense variants (p.Ile100Phe, p.Gly196Val, p.Ile204Thr, p.Gln226Pro, p.Lys233Asn, and p.Ser396Arg). The novel nonsense mutation (p.Gln281 *) was a heterozygous C>T nucleotide change (c.841C>T) predicted to result in a truncated protein due to a premature stop codon in the MKRN3 gene. The nonsense mutation (p.Gln281 *) was only identified in one of the girls and her younger brother. Compared to previous reports on MKRN3 mutations in familial and sporadic cases of CPP, the present study reveals a relatively low number of MKRN 3 mutations in Korean girls with CPP. Larger samples of children with CPP and MKRN3 mutations are necessary in order to clarify whether the clinical course of puberty may differ as compared to idiopathic CPP.

Development and evaluation of a multiplex PCR for eight plasmid-mediated quinolone-resistance determinants

The objective of this study was to develop and validate an expanded multiplex PCR assay for the simultaneous detection of eight plasmid-mediated quinolone-resistance determinants in Enterobacteriaceae. Primers were designed to amplify conserved fragments of qnrABCDS, qepA, oqxAB and aac(6′)-Ib-cr genes and were optimized in uniplex and multiplex PCR assays with control template DNA. The assay was used to determine the prevalence of plasmid-mediated quinolone resistance (PMQR) genes in 174 ciprofloxacin-resistant and 43 ciprofloxacin-susceptible extraintestinal pathogenic Escherichia coli isolates. Each resistance gene could be detected alone and in combination. PMQR determinants were detected in 65 ciprofloxacin-resistant isolates (37 %) and one ciprofloxacin-susceptible isolate (2 %). Prevalences of the identified determinants were: aac(6′)-Ib-cr, 34.5 %; qnrS, 1.1 %; qepA, 1.1 %; and oqxAB, 0.6 %. In conclusion, we developed an eight-target multiplex PCR for the accurate detection of PMQR genes and confirmed that PMQR prevalence remains low among human Escherichia coli clinical isolates in the UK.

Using formal concept analysis for microarray data comparison

Microarray technologies, which can measure tens of thousands of gene expression values simultaneously in a single experiment, have become a common research method for biomedical researchers. Computational tools to analyze microarray data for biological discovery are needed. In this paper, we investigate the feasibility of using formal concept analysis (FCA) as a tool for microarray data analysis. The method of FCA builds a (concept) lattice from the experimental data together with additional biological information. For microarray data, each vertex of the lattice corresponds to a subset of genes that are grouped together according to their expression values and some biological information related to gene function. The lattice structure of these gene sets might reflect biological relationships in the dataset. Similarities and differences between experiments can then be investigated by comparing their corresponding lattices according to various graph measures. We apply our method to microarray data derived from influenza-infected mouse lung tissue and healthy controls. Our preliminary results show the promise of our method as a tool for microarray data analysis.

Genetic association analysis of serotonin system genes in bipolar affective disorder

OBJECTIVE

This study examined the putative role of serotonin genes in the etiology of bipolar affective disorder.

METHOD

Genetic association analysis was performed for individuals with bipolar affective disorder and unaffected subjects closely matched in age, sex, and ethnic background (N=103 in each group). The allele and genotype frequencies of polymorphisms at the genes for serotonin receptors HTR1A, HTR1Dalpha, HTR1Dbeta, HTR2A, HTR2C, HTR7, tryptophan hydroxylase (TPH), and the serotonin transporter (hSERT) were compared in the two groups of subjects.

RESULTS

Statistically significant positive associations were found for HTR2A and hSERT polymorphisms. However, results from an independent replication group of over 100 patients with bipolar affective disorder and their matched comparison subjects failed to confirm these associations.

CONCLUSIONS

These results suggest that the serotonin genes studied are not associated with bipolar affective disorder, although transmission disequilibrium studies are required in order to confirm this conclusion.