Application of Long-Read Nanopore Sequencing to the Search for Mutations in Hypertrophic Cardiomyopathy.

Increasing evidence suggests that both coding and non-coding regions of sarcomeric protein genes can contribute to hypertrophic cardiomyopathy (HCM). Here, we introduce an experimental workflow (tested on four patients) for complete sequencing of the most common HCM genes (MYBPC3, MYH7, TPM1, TNNT2, and TNNI3) via long-range PCR, Oxford Nanopore Technology (ONT) sequencing, and bioinformatic analysis. We applied Illumina and Sanger sequencing to validate the results, FastQC, Qualimap, and MultiQC for quality evaluations, MiniMap2 to align data, Clair3 to call and phase variants, and Annovar's tools and CADD to assess pathogenicity of variants. We could not amplify the region encompassing exons 6-12 of MYBPC3. A higher sequencing error rate was observed with ONT (6.86-6.92%) than with Illumina technology (1.14-1.35%), mostly for small indels. Pathogenic variant p.Gln1233Ter and benign polymorphism p.Arg326Gln in MYBPC3 in a heterozygous state were found in one patient. We demonstrated the ability of ONT to phase single-nucleotide variants, enabling direct haplotype determination for genes TNNT2 and TPM1. These findings highlight the importance of long-range PCR efficiency, as well as lower accuracy of variant calling by ONT than by Illumina technology; these differences should be clarified prior to clinical application of the ONT method.

Impact of the Polymorphism of the PACRG and CD80 Genes on the Development of the Different Stages of Tuberculosis Infection.

BACKGROUND: Tuberculosis (TB) is one of the most significant health-care problems worldwide. The host's genetics play an important role in the development of TB in humans. The disease progresses through several stages, each of which can be under the control of different genes. The precise genes influencing the different stages of the disease are not yet identified. The aim of the current study was to determine the associations between primary and secondary TB and the polymorphisms of novel candidate genes for TB susceptibility, namely CD79A, HCST, CXCR4, CD4, CD80, CP, PACRG, and CD69. METHODS: A total of 357 patients with TB (130 cases with primary TB and 227 cases with secondary TB) from the Siberian region of Russia as well as 445 healthy controls were studied. The study was performed at the Research Institute of Medical Genetics, Tomsk NRMC, Tomsk, Russia, between July 2015 and November 2016. Genotyping was carried out using MALDI-TOF mass spectrometry and PCR-RFLP. The associations between the single-nucleotide polymorphisms and TB were assessed using logistic regression adjusting for covariates (age and gender). Multiple testing was addressed via the experiment-wise permutation approach. The statistical significance threshold was a P value less than 0.05 for the permutation P values. The analyses were done in R 3.2 statistical software. RESULTS: An association was established between the rs1880661 variant of the CD80 gene and secondary TB and the rs10945890 variant of the PACRG gene and both primary and secondary TB. However, the same allele of PACRG appeared to be both a risk factor for reactivation (secondary TB) and a protector against primary infection. CONCLUSION: The results suggested that the CD80 and PACRG genes were associated with susceptibility to different forms of TB infection in the Russian population.

A de novo microtriplication at 4q21.21-q21.22 in a patient with a vascular malignant hemangioma, elongated sigmoid colon, developmental delay, and absence of speech.

The widespread application of array comparative genomic hybridization (aCGH) has provided new insights into the clinical significance of copy number variations (CNVs) in the human genome. Many microdeletion syndromes have recently been linked to corresponding reciprocal microduplication syndromes related to CNVs in the same chromosomal regions. However, the extent of CNVs may not be restricted to only microduplications but may also include microtriplications or even quadruplications. 4q21 microdeletion syndrome is one of these recently described syndromes. The phenotype includes growth restriction, neonatal hypotonia, severe developmental delay, absent or delayed speech, and distinct facial features. The minimal critical deleted region, which is 1.3 Mb in size, contains the PRKG2, RASGEF1B, HNRNPD, HNRPDL, and ENOPH1 genes. Here, we report a 5.4-year-old girl with developmental delay, absence of speech, muscular hypertension, macrocephaly, a broad forehead, frontal bossing, relatively elongated extremities, a vascular malignant hemangioma in anamnesis, and elongated sigmoid colon. aCGH revealed a microtriplication at 4q21.21-q21.22 that was 1.61 Mb in size. This de novo microtriplication included nine genes (BMP3, PRKG2, RASGEF1B, HNRNPD, HNRPDL, ENOPH1, TMEM150C, LINC00575, and SCD5) and overlapped with the minimal critical region for 4q21 microdeletion syndrome. Some clinical features of the patient were similar to those of 4q21 microdeletion (macrocephaly, frontal bossing, developmental delay, absence of speech, and anxiety), whereas others were mirrored (elongated extremities and muscular hypertension). The first identified case of a de novo microtriplication at 4q21.21-q21.22 emphasizes the clinical significance of CNVs at 4q21 for patients with developmental delay and absence of speech. © 2016 Wiley Periodicals, Inc.