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Context Congenital pituitary hormone deficiencies with syndromic phenotypes and/or familial occurrence suggest genetic hypopituitarism; however, in many such patients the underlying molecular basis of the disease remains unknown. Objective To describe patients with syndromic hypopituitarism due to biallelic loss-of-function variants in TBC1D32, a gene implicated in Sonic Hedgehog (Shh) signaling. Setting Referral center. Patients A Finnish family of 2 siblings with panhypopituitarism, absent anterior pituitary, and mild craniofacial dysmorphism, and a Pakistani family with a proband with growth hormone deficiency, anterior pituitary hypoplasia, and developmental delay. Interventions The patients were investigated by whole genome sequencing. Expression profiling of TBC1D32 in human fetal brain was performed through in situ hybridization. Stable and dynamic protein-protein interaction partners of TBC1D32 were investigated in HEK cells followed by mass spectrometry analyses. Main Outcome Measures Genetic and phenotypic features of patients with biallelic loss-of-function mutations in TBC1D32. Results The Finnish patients harboured compound heterozygous loss-of-function variants (c.1165_1166dup p.(Gln390Phefs*32) and c.2151del p.(Lys717Asnfs*29)) in TBC1D32; the Pakistani proband carried a known pathogenic homozygous TBC1D32 splice-site variant c.1372 + 1G > A p.(Arg411_Gly458del), as did a fetus with a cleft lip and partial intestinal malrotation from a terminated pregnancy within the same pedigree. TBC1D32 was expressed in the developing hypothalamus, Rathke’s pouch, and areas of the hindbrain. TBC1D32 interacted with proteins implicated in cilium assembly, Shh signaling, and brain development. Conclusions Biallelic TBC1D32 variants underlie syndromic hypopituitarism, and the underlying mechanism may be via disrupted Shh signaling.

Objectives The aim of the study was to estimate the levels of transmitted drug resistance (TDR) in HIV-1 using very sensitive assays to detect minority drug-resistant populations. Methods We tested unlinked anonymous serum specimens from sexual health clinic attendees, who had not received an HIV diagnosis at the time of sampling, by both standard genotyping and using minority detection assays. Results By standard genotyping, 21 of 165 specimens (12.7%) showed evidence of drug resistance, while, using a combination of standard genotyping and minority mutation assays targeting three commonly observed drug resistance mutations which cause high-level resistance to commonly prescribed first-line antiretroviral therapy (ART), this rose to 32 of 165 (19.4%). This increase of 45% in drug resistance levels [95% confidence interval (CI) 15.2–83.7%; P=0.002] was statistically significant. Almost all of this increase was accounted for by additional detections of the M184V mutation. Conclusions Future surveillance studies of TDR in the United Kingdom should consider combining standard genotyping and minority-specific assays to provide more accurate estimates, particularly when using specimens collected from chronic HIV infections in which TDR variants may have declined to low levels.

We report the evaluation of a new real-time PCR assay for hepatitis C virus (HCV) genotyping. The assay design is such that genotype 1 isolates are typed by amplification targeting the nonstructural 5b (NS5b) subgenomic region. Non-genotype 1 isolates are typed by type-specific amplicon detection in the 5′ noncoding region (5′NC) (method 1; HCV genotyping analyte-specific reagent assay). This method was compared with 5′NC reverse hybridization (method 2; InnoLiPA HCV II) and 5′NC sequencing (method 3; Trugene HCV 5′NC). Two hundred ninety-five sera were tested by method 1; 223 of them were also typed by method 2 and 89 by method 3. Sequencing and phylogenetic analysis of an NS5b fragment were used to resolve discrepant results. Suspected multiple-genotype infections were confirmed by PCR cloning and pyrosequencing. Even though a 2% rate of indeterminates was obtained with method 1, concordance at the genotype level with results with methods 2 and 3 was high. Among eight discordant results, five mixed infections were confirmed. Genotype 1 subtyping efficiencies were 100%, 77%, and 74% for methods 1, 2, and 3, respectively; there were 11/101 discordants between methods 1 and 2 (method 1 was predominantly correct) and 2/34 between methods 2 and 3. Regarding genotype 2, subtyping efficiencies were 100%, 45%, and 92% by methods 1, 2, and 3, respectively; NS5b sequencing of discordants (16/17) revealed a putative new subtype within genotype 2 and that most subtype calls were not correct. Although only sequencing-based methods provide the possibility of identifying new variants, the real-time PCR method is rapid, straightforward, and simple to interpret, thus providing a good single-step alternative to more-time-consuming assays.

An HIV-1/hepatitis C virus (HCV) co-infected patient with haemophilia received a 48-week course of pegylated interferon-α-2b and ribavirin therapy for genotype 5a HCV infection. Virological response was achieved at week 24. At the end of treatment, HCV RNA in serum was detected and identified to belong to genotype 2b, rather than genotype 5a. A sensitive method for identifying minority HCV genotypes in pre-treatment serum showed genotype 2b HCV carriage prior to treatment. Sequencing the interferon sensitivity-determining region of the HCV NS5A gene obtained from pre-, intra- and post-treatment sera revealed emergence of quasispecies bearing R → K and M → A/T mutations at codons 2222 and 2223, respectively. Occult presence of minority HCV subpopulations and their acquisition of mutations following therapy can result in poor treatment outcome.

The prevalence of concurrent multitypic hepatitis C virus (HCV) infection is uncertain. A sensitive and specific approach to identifying minority HCV genotypes in blood is presented. Following serum extraction and reverse transcription PCR to amplify cDNA originating from the viral 5′ noncoding region, the amplified product mixture was treated with genotype-specific restriction endonuclease to digest the dominant genotype. Residual amplicons were subjected to PCR cloning and then to real-time DNA sequencing using a Pyrosequencer to identify the remaining genotypes. Dilution experiments showed that minority genotypes may be detected when they represent 1:10,000 of the total population and in serum specimens with viral loads as low as 1,000 IU/ml. Of 37 patients with bleeding disorders and 44 injecting drug users, infection by more than one HCV genotype was found in 7 (19%) and 4 (9%) patients, respectively. The low rate of detection in people at high risk of repeated HCV infection suggests that multitypic HCV carriage is uncommon.

OBJECTIVES To determine the contribution of transmission clusters to transmitted drug resistance (TDR) in newly diagnosed antiretroviral-naive HIV-1-infected patients in Northern Greece during 2000-07. METHODS The prevalence of TDR was estimated in 369 individuals who were diagnosed with HIV-1 infection in the period 2000-07 at the National AIDS Reference Laboratory of Northern Greece. Phylogenetic analysis was performed using a maximum likelihood method on partial pol sequences. TDR was defined in accordance with the surveillance drug resistance mutation list (2009 update). RESULTS The overall prevalence of TDR in our population was 12.5% [46/369, 95% confidence interval (CI) 9.1%-15.8%], comprising 7.6% (28/369) resistant to nucleoside reverse transcriptase inhibitors, 5.4% (20/369) resistant to non-nucleoside reverse transcriptase inhibitors and 3.3% (12/369) resistant to protease inhibitors. Dual class resistance was identified in 3.8% (14/369). Infection with subtype A was the sole predictor associated with TDR in multivariate analysis (odds ratio 2.15, 95% CI 1.10-4.19, P = 0.025). Phylogenetic analyses revealed three statistically robust transmission clusters involving drug-resistant strains, including one cluster of 12 patients, 10 of whom were infected with a strain carrying both T215 revertants and Y181C mutations. CONCLUSIONS Our findings underline the substantial impact of transmission networks on TDR in our population.

Background The detection of mutations associated with drug resistance in HIV type-1 might be increased by applying minority species assays capable of identifying low frequency mutations in comparison with the use of population sequencing alone. Because minority species assays are mutation-specific, the benefit of this approach differs depending on the mutation being detected. Methods We performed a systematic review of published data reporting detection of genotypic drug resistance using allele-specific (AS)-PCR minority assays and by standard DNA sequencing in drug-naive populations. We calculated the fold increase of mutation detection for each study and pooled these via meta-analysis, displaying results using Forest plots. Results Our studies revealed an increase in detection of 1.9-fold (95% confidence interval [CI] 1.3–2.7; PConclusions Additional detection of drug resistance mutations using AS-PCR minority mutation assays vary significantly depending on the mutation examined; however, the most marked increase in detection of resistance mutations was observed for M184V, a mutation seldom detected by standard techniques in drug-naive patients. We suggest that the presence of drug resistance mutations can be more accurately estimated using a combination of AS-PCR and standard genotyping.

Sir, In a recent report, we described a laboratory procedure to perform HIV-1 genotypic drug resistance testing from dried blood spots (DBS). The methodology as a whole was subjected to rigorous validation. However, it has since been pointed out to us that we had not demonstrated that the process for cleaning the hole-punch used to excise DBS from filter paper was sufficient to prevent cross-contamination between samples. Our DBS excision technique involves the use of a hand-held 6 mm diameter office hole-punch (catalogue number 272575—Staples, Doncaster, UK). This is used to punch a pair of DBS per specimen from a filter paper collection card. It is cleaned by punching five filter paper spots from a fresh, unused card, before being used again to excise from a DBS specimen. In order to address these concerns, studies were performed to investigate the possibility that this procedure could generate false positives due to contamination of the hole-punch. Such methodological concerns are important considering the use of DBS as a widespread surveillance method. Ten DBS per specimen were prepared from three venous whole blood specimens collected with EDTA anticoagulant from HIV-infected individuals with known high viral load (.1 10 copies/mL). HIV viral load confirmation was performed using the COBAS Ampliprep HIV Taqman Assay (Roche, Lewes, UK). A further 30 DBS were prepared from normal human whole blood collected with citrate anticoagulant. DBS were prepared, stored and tested as per our earlier report. Two punches from each DBS were used for nucleic acid extraction. Alternate HIV and normal whole blood DBS were excised and tested consecutively. For each DBS replicate, PCR reactions to amplify fragments of the human b-globin gene, and two HIV subgenomic regions [protease spanning nucleotide positions 2057– 2979, reverse transcriptase (RT) 2813–3618 of the HIV genome, numbering as HXB2 reference strain, K03455], were carried out. For each normal whole blood replicate DBS, only the human b-globin gene fragment was successfully amplified. HIV nucleic acids were not detected by nested PCR in any normal whole blood replicate, in either the protease or RT regions. For each HIV whole blood DBS replicate, human b-globin and HIV protease and RT genes were detected by PCR. The outcome of these studies is summarized in Table 1, along with HIV viral load data for each patient specimen. Several studies have reported different methods to excise HIV DBS for drug resistance genotyping. The studies of Ziemniak et al. reported the excision of DBS using a sterile disposable razor blade. Bertagnolio et al. reported the use of disposable sterile scissors to excise DBS specimens. Others have reported the use of scissors and forceps sterilized between uses by spraying with a solution of 70% ethanol, before being completely dried. These methods for the excision of DBS from filter paper collection cards are cumbersome, timing-consuming, expensive and—in the case of razor blade use—potentially hazardous. A recent study by Driver et al. reported the use of a manual hole-punch to excise DBS for detection of HIV DNA by PCR, for use in the diagnosis of mother-to-child transmissions. Extensive replicate testing revealed no false positives regardless of whether the hole-punch was cleaned between DBS or not. Taken together with our study, the use of the manual hole-punch is a cost-effective, labour-saving method for DBS excision for HIV drug resistance genotyping, for which specimen crosscontamination is unlikely.

As antiretroviral therapy scale-up proceeds in developing countries, simple and inexpensive procedures are required to monitor the prevalence and transmission of drug-resistant HIV strains to ensure optimal use of antiviral therapy. This article reviews new surveillance methods and practices used to monitor drug resistance in the developing world.Several recently published studies report the successful development of methods using dried blood spots, collected on filter paper, for HIV drug resistance genotyping tests. In concert to antiretroviral therapy rollout, the WHO has developed a laboratory network and sought to implement surveillance of transmitted drug resistance in developing countries. A small number of developing world prevalence studies have thus far been published using dried blood spots. These studies reveal low rates of transmitted drug resistance. Other studies indicate that the use of dried blood spots for HIV drug resistance surveillance may possibly lead to overestimates.The use of dried blood spots as a method of specimen collection and storage is simple, inexpensive and is an appropriate technique for the surveillance of transmitted HIV drug resistance.

We present the evaluation of a methodology for the genotypic assessment of human immunodeficiency virus type-1 (HIV-1) drug resistance, optimized for use with dried blood spots (DBS).The ability to generate HIV-1 protease (PR) and reverse transcriptase (RT) contiguous amplicons and nucleotide sequences from DBS was evaluated. Different collection matrices and extraction methodologies were compared. The relative subtype sensitivity of the amplification strategy was assessed using a comprehensive panel of plasmids representing A-H subtypes. A panel of DBS and plasma specimens was subjected to HIV genotyping. Sequences generated from each sample type were compared.Extensive replicate testing revealed most sensitivity with the use of 903 filter paper and silica/guanidine extraction, which had an estimated 95% inclusivity endpoint of 1542 proviral copies/mL, as compared with 21 573 proviral copies/mL for the FTA system. All HIV-1 group M subtypes analysed-with the exception of subtypes A2, AE, AG, F and H-had a relative sensitivity of/=10 plasmid copies/PCR reaction. The PCR was multiplexed to include amplification of a human housekeeping gene to monitor the integrity of the human genomic DNA. Using a panel of clinical samples, we demonstrated the ability to amplify and sequence from 83% (n = 10) in the PR region and 100% (n = 12) in the RT region, of samples with detectable viral load. All specimens with an HIV-1 RNA load/=1000 copies/mL were successfully amplified and sequenced. Twelve specimens had pol genotyping from both plasma and DBS samples. Sequence analysis and drug resistance interpretation revealed that 10 (83%) provided concordant drug resistance interpretation.Our results demonstrate that the technique is appropriate for surveillance of drug resistance in untreated individuals and those with virological failure on therapy.

Background: Molecular genetic testing is recommended for diagnosis of inherited cardiac disease, to guide prognosis and treatment, but access is often limited by cost and availability. Recently introduced high-throughput bench-top DNA sequencing platforms have the potential to overcome these limitations. Methodology/Principal Findings: We evaluated two next-generation sequencing (NGS) platforms for molecular diagnostics. The protein-coding regions of six genes associated with inherited arrhythmia syndromes were amplified from 15 human samples using parallelised multiplex PCR (Access Array, Fluidigm), and sequenced on the MiSeq (Illumina) and Ion Torrent PGM (Life Technologies). Overall, 97.9% of the target was sequenced adequately for variant calling on the MiSeq, and 96.8% on the Ion Torrent PGM. Regions missed tended to be of high GC-content, and most were problematic for both platforms. Variant calling was assessed using 107 variants detected using Sanger sequencing: within adequately sequenced regions, variant calling on both platforms was highly accurate (Sensitivity: MiSeq 100%, PGM 99.1%. Positive predictive value: MiSeq 95.9%, PGM 95.5%). At the time of the study the Ion Torrent PGM had a lower capital cost and individual runs were cheaper and faster. The MiSeq had a higher capacity (requiring fewer runs), with reduced hands-on time and simpler laboratory workflows. Both provide significant cost and time savings over conventional methods, even allowing for adjunct Sanger sequencing to validate findings and sequence exons missed by NGS. Conclusions/Significance: MiSeq and Ion Torrent PGM both provide accurate variant detection as part of a PCR-based molecular diagnostic workflow, and provide alternative platforms for molecular diagnosis of inherited cardiac conditions. Though there were performance differences at this throughput, platforms differed primarily in terms of cost, scalability, protocol stability and ease of use. Compared with current molecular genetic diagnostic tests for inherited cardiac arrhythmias, these NGS approaches are faster, less expensive, and yet more comprehensive.

In the late 1980s an HIV-1 epidemic emerged in Romania that was dominated by subtype F1. The main route of infection is believed to be parenteral transmission in children. We sequenced partial pol coding regions of 70 subtype F1 samples from children and adolescents from the PENTA-EPPICC network of which 67 were from Romania. Phylogenetic reconstruction using the sequences and other publicly available global subtype F sequences showed that 79% of Romanian F1 sequences formed a statistically robust monophyletic cluster. The monophyletic cluster was epidemiologically linked to parenteral transmission in children. Coalescent-based analysis dated the origins of the parenteral epidemic to 1983 [1981–1987; 95% HPD]. The analysis also shows that the epidemic's effective population size has remained fairly constant since the early 1990s suggesting limited onward spread of the virus within the population. Furthermore, phylogeographic analysis suggests that the root location of the parenteral epidemic was ...

Purpose of the study: To determine the contribution of transmission clusters on transmitted drug resistance (TDR) in newly diagnosed antiretroviral naive patients in Northern Greece, during 2000 -2007. Methods: Viral reverse transcriptase and protease genes from 369 individuals with newly diagnosed HIV-1 infection were sequenced at baseline. A maximum-likelihood phylogenetic analysis method was employed to examine for linkage between viral isolates. Clinical data were retrieved from the database and cross-referenced with the patients' medical files. Transmitted drug resistance was defined in accordance with the Surveillance Drug Resistance Mutation (SDRM) 2009 list. Supplement: Abstracts of the Tenth International Congress on Drug Therapy in HIV Infection http://www.biomedcentral.com/content/pdf/1758-2652-13-S4-info.pdf Conference: Tenth International Congress on Drug Therapy in HIV Infection 7-11 November 2010 Glasgow, UK (Published: 8 November 2010) doi:10.1186/1758-2652-13-S4-P125 Cite this article as: Skoura et al.: Transmitted drug resistance associated with transmission clusters in newly diagnosed antiretroviral-naive patients in Northern Greece. Journal of the International AIDS Society 2010 13(Suppl 4):P125. Full text: PubMed Central: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3112900/