The Common miRNA Signatures Associated with Mitochondrial Dysfunction in Different Muscular Dystrophies.

Secondary mitochondrial damage in skeletal muscles is a common feature of different neuromuscular disorders, which fall outside the mitochondrial cytopathies. The common cause of mitochondrial dysfunction and structural changes in skeletal muscle tissue remains to be discovered. Although they are associated with different clinical, genetic, and pathologic backgrounds, the pathomechanisms underlying neuromuscular disorders might be attributed to the complex interaction and cross talk between mitochondria and the associated miRNAs. This study aimed to identify the common miRNA signatures that are associated with mitochondrial damage in different muscular dystrophies (MDs; Duchenne muscular dystrophy, megaconial congenital muscular dystrophy, Ullrich congenital muscular dystrophy, and α-dystroglycanopathy). The miRNome profiles of skeletal muscle biopsies acquired from four different MD groups and control individuals were analyzed by miRNA microarray. We identified 17 common up-regulated miRNAs in all of the tested MD groups. A specific bioinformatics approach identified 10 of these miRNAs to be specifically related to the mitochondrial pathways. Six miRNAs, miR-134-5p, miR-199a-5p, miR-382-5p, miR-409-3p, miR-497-5p, and miR-708-5p, were associated with the top four mitochondrial pathways and were thus selected as priority candidates for further validation by quantitative real-time PCR analysis. We demonstrate, for the first time, common up-regulated miRNAs that are associated with mitochondrial damage in different MD groups, therefore contributing to the pathophysiology. Our findings may open a new gate toward therapeutics.

Genotype and phenotype evaluation of patients with primary ciliary dyskinesia: First results from Turkey.

BACKGROUND AND OBJECTIVE: Primary ciliary dyskinesia (PCD) is a rare and genetically heterogeneous disease and the severity of the disease related with genetic analysis has been described in some previous studies. The main aim of our study was to describe the clinical characteristics and laboratory findings of patients with genetically diagnosed PCD and to investigate the correlation between clinical, radiologic, and laboratory findings and genetic analyses of these patients. METHOD: This is a cohort study in which we analyzed the clinical characteristics, laboratory findings, and genetic results of 46 patients with genetically diagnosed PCD through whole-exome sequencing at our single center from a total of 265 patients with PCD within a 5-year period. RESULTS: Genetic analysis revealed pathogenic variants in DNAH5 (n = 12 individuals, 12 families), CCDC40 (n = 9 individuals, six families), RSPH4A (n = 5 individuals, three families), DNAH11 (n = 4 individuals, four families), HYDIN (n = 5 individuals, five families), CCNO (n = 4 individuals, four families), DNAI1 (n = 2 individuals, one family), ARMC4 (n = 2 individuals, two families), TTC25 (n = 1), DNAH1 (n = 1), and CCDC39 (n = 1) genes. Although not statistically significant, the age at diagnosis was lower (median: 3 years; range, 6 months-4 years) in patients with CCNO pathogenic variants due to the early reporting of symptoms, and the median body mass index (BMI) and BMI z scores were lower in patients at 18.7 and 16 kg/m2 , and -0.78 and -1.2 with CCDC40 and CCNO pathogenic variants, respectively. The median forced expiratory flow in 1 second (FEV1%), forced vital capacity (FVC%), and forced expiratory flow (FEF)25-75% were 53%, 64%, and 28%, respectively; these parameters were also lower in the CCDC40 group than in the other groups. There was no significant correlation between the genetic results and symptoms, radiologic findings, and microbiologic data of patients with PCD. CONCLUSION: In PCD, there was significant heterogeneity of lung disease, patients who had pathogenic variants in CCNO presented earlier, and those with CCDC40 and CCNO had worse lung disease, and poorer nutritional status compared with the other subgroups. We hope that whole genotype-phenotype and clinical relationships will be identified in PCD.

Identification of two novel PNPLA1 mutations in Turkish families with autosomal recessive congenital ichthyosis.

Dökmeci-Emre S, Taskiran ZE, Yüzbasioglu A, Önal G, Akarsu AN, Karaduman A, Özgüç M. Identification of two novel PNPLA1 mutations in Turkish families with autosomal recessive congenital ichthyosis. Turk J Pediatr 2017; 59: 475-482. Autosomal recessive congenital ichthyosis (ARCI) is a group of inherited keratinization disorders that are characterized by abnormal epidermal keratinization. ARCI patients generally represent serious symptoms including collodion baby phenotype accompanied by dehydration, heat loss, electrolytic imbalance, and sepsis. ARCI shows high degree of clinical and genetic heterogeneity. To date, nine genes were shown to be responsible for ARCI phenotype. One of these genes, patatin-like phospholipase domain containing protein-1 (PNPLA1) was suggested to be involved in the synthesis of ω-O-acylceramides related to epidermal cornified lipid envelope organization. In addition to previously reported PNPLA1 mutations, we report two novel PNPLA1 mutations including one novel missense mutation c.335C > A (p.Ser112Tyr) and one novel deletion mutation c.733_735delTAC (p.Tyr245del) in Turkish ARCI patients from unrelated consanguineous families. We also report previously reported missense mutation c.514G > A (p.Asp172Asn) in Turkish ARCI patients. Novel PNPLA1 mutations were shown to be located in the catalytic patatin domain of PNPLA1 gene. Identification of novel mutations in PNPLA1 gene expands the mutational spectrum in the causative gene. Increase in the total number of cases has high diagnostic value in terms of genotype-phenotype correlation in ARCI patients.

Discovery of biomarkers in rare diseases: innovative approaches by predictive and personalized medicine.

There are more than 8000 rare diseases (RDs) that affect >5 % of the world's population. Many of the RDs have no effective treatment and lack of knowledge creates delayed diagnosis making management difficult. The emerging concept of the personalized medicine allows for early screening, diagnosis, and individualized treatment of human diseases. In this context, the discovery of biomarkers in RDs will be of prime importance to enable timely prevention and effective treatment. Since 80 % of RDs are of genetic origin, identification of new genes and causative mutations become valuable biomarkers. Furthermore, dynamic markers such as expressed genes, metabolites, and proteins are also very important to follow prognosis and response the therapy. Recent advances in omics technologies and their use in combination can define pathophysiological pathways that can be drug targets. Biomarker discovery and their use in diagnosis in RDs is a major pillar in RD research.

Rationale, design and objectives of ARegPKD, a European ARPKD registry study.

BACKGROUND: Autosomal recessive polycystic kidney disease (ARPKD) is a rare but frequently severe disorder that is typically characterized by cystic kidneys and congenital hepatic fibrosis but displays pronounced phenotypic heterogeneity. ARPKD is among the most important causes for pediatric end stage renal disease and a leading reason for liver-, kidney- or combined liver kidney transplantation in childhood. The underlying pathophysiology, the mechanisms resulting in the observed clinical heterogeneity and the long-term clinical evolution of patients remain poorly understood. Current treatment approaches continue to be largely symptomatic and opinion-based even in most-advanced medical centers. While large clinical trials for the frequent and mostly adult onset autosomal dominant polycystic kidney diseases have recently been conducted, therapeutic initiatives for ARPKD are facing the challenge of small and clinically variable cohorts for which reliable end points are hard to establish. METHODS/DESIGN: ARegPKD is an international, mostly European, observational study to deeply phenotype ARPKD patients in a pro- and retrospective fashion. This registry study is conducted with the support of the German Society for Pediatric Nephrology (GPN) and the European Study Consortium for Chronic Kidney Disorders Affecting Pediatric Patients (ESCAPE Network). ARegPKD clinically characterizes long-term ARPKD courses by a web-based approach that uses detailed basic data questionnaires in combination with yearly follow-up visits. Clinical data collection is accompanied by associated biobanking and reference histology, thus setting roots for future translational research. DISCUSSION: The novel registry study ARegPKD aims to characterize miscellaneous subcohorts and to compare the applied treatment options in a large cohort of deeply characterized patients. ARegPKD will thus provide evidence base for clinical treatment decisions and contribute to the pathophysiological understanding of this severe inherited disorder.

Chanarin-Dorfman syndrome: Genotype-Phenotype Correlation.

Chanarin-Dorfman syndrome is an autosomal recessive lipid storage disease characterized by non-bullous congenital ichthyosiform erythroderma, and involvement of the liver, muscles and central nervous system due to a multisystemic accumulation of neutral lipids in various types of cells. Less than 100 affected individuals have been reported worldwide, the majority from the Mediterranean and Middle-East countries, especially Turkey. We present clinical and molecular data of four affected relatives with Chanarin-Dorfman syndrome homozygous for a N209X mutation in ABHD5, and provide a short review by comparing patients with N209X homozygous mutations to patients with other ABHD5 mutations. No major clinical differences exist between individuals with an N209X mutation and those with other mutations, which argues against a genotype/phenotype correlation.

Chanarin-dorfman syndrome with multi-system involvement in two siblings.

UNLABELLED: Chanarin-Dorfman syndrome (CDS) is a very rare autosomal recessive inherited neutral lipid metabolism disorder associated with congenital ichthyosis and multi-system involvement. Observation of lipid vacuoles in neutrophils (Jordan's anomaly) in peripheral blood smears in patients with ichthyosiform erythroderma is diagnostic. Herein we present 2 siblings with CDS that were referred to Dokuz Eylul University School of Medicine Department of Pediatrics due to ichthyosis. They had hepatomegaly, cataract, growth retardation, and sensorineural hearing loss. Some lipid vacuoles in neutrophils were noted in peripheral blood smear evaluation. Genetic analysis showed homozygous N209X mutation in both patients. They were put on a low-fat high-carbohydrate diet supplemented with medium-chain fatty acids. During 6 months of follow-up, no improvement was observed in both patients. In conclusion, although CDS is a rare lipid storage disease, it should always be a consideration in patients with congenital ichthyosis, especially those with extracutaneous symptoms or signs. The diagnosis of CDS is made based on a very simple test-peripheral blood smear. CONFLICT OF INTEREST: None declared.

Biobanking: sample acquisition and quality assurance for 'omics' research.

After the human genome sequence has been solved using random individuals through the Human Genome Project (HGP), rapid advances in whole genome sequencing technologies with effective use at a reasonable cost, is moving the genomics research field to an era of 'personal genomes'. Biobanks in this context have played an important role by providing high quality biological samples for genomics and functional genomics research. Here we are describing biobanking and the importance of governance in biobanking activity for reliable and reproducible high throughput 'omics' data.

Novel mutations of the MLC1 gene in Turkish patients.

Megalencephalic Leukoencephalopathy with Subcortical Cysts (MLC) is a rare autosomal recessive disease presenting with increased head circumference at birth or in early infancy. MLC1 (MIM 605908) mutations are responsible for this disorder. In this study, we sequenced the entire coding region of the MLC1 gene in 13 patients and detected five novel nucleotide variations in six of them. Two of the novel variations created a missense amino acid change and the other three were located in the introns and were putative splice mutations. One novel missense variation was observed in two unrelated patients from the central Black Sea region, and the data suggested a founder haplotype for this novel variation. Similarly, three unrelated patients with the previously reported p.Thr118Arg mutation shared a common haplotype. These data suggest an Anatolian origin for these two mutations. As in the previous reports, it is not possible to correlate the clinical phenotype of the patients with the mutation spectra.

Molecular analysis of Chanarin-Dorfman syndrome (CDS) patients: Identification of novel mutations in the ABHD5 gene.

Chanarin-Dorfman syndrome (CDS) is an autosomal recessive metabolic disorder associated with congenital ichthyosis and a multisystemic accumulation of neutral lipids in various types of cells. Recently, mutations of the ABHD5 gene were identified as the cause of CDS. In this work, we carried out molecular analysis of the ABHD5 gene in 6 unrelated patients. We identified one previously reported mutation, N209X and two novel genetic alterations; a nonsense mutation (p.Y50X) and missense mutation (p.S73A).

Changes in the expression of selenoproteins in mesial temporal lobe epilepsy patients.

Selenoproteins are enzymes containing selenium in their structure and are involved in cellular processes such as defense against oxidative stress and cell survival. The aim of this study is to investigate the expression of four selenoproteins (GPX1, TRXR1, SELP and SELW) in the hippocampus of intractable mesial temporal lobe epilepsy (MTLE) patients who underwent curative surgery. The selenoproteins is investigated at the mRNA level via RT-PCR and in situ hybridization and by immunostaining at the protein level. The expression of SELW exhibited a relative induction of more than tenfold, and immunostaining findings provided evidence that this upregulation is confined to neurons. GPX1 was also upregulated 2.3-fold, and TRXR1 was downregulated between 70 and 20% in MTLE patients. The profound induction of SELW has been accompanied by GPX1 and displayed a strong correlation with BCL2 expression, suggesting a protective role for these selenoproteins, and may be an indicator of a defense mechanism in surviving neurons.

Androgen receptor immunostaining and androgen receptor messenger ribonucleic acid expression are increased in cremaster muscles associated with undescended testis.

OBJECTIVES: To determine and compare androgen receptor (AR) immunostaining and AR messenger ribonucleic acid (mRNA) expression in cremaster muscles associated with descended or undescended testis. METHODS: Eight boys with descended testis but with inguinal hernia and 8 boys with undescended testis were evaluated. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and free testosterone levels were determined, and samples of cremaster muscles were immunostained for AR. Groups were compared by unpaired t tests and Fisher's exact tests; P values of <0.05 were considered significant. Samples of cremaster muscles were obtained from another 5 boys with descended testis but with inguinal hernia and 5 boys with undescended testis. The expression of AR mRNA in those samples was determined by semiquantitative reverse transcriptase polymerase chain reaction. RESULTS: Serum FSH, LH, testosterone, and free testosterone levels were similar among groups. None of the samples from boys with descended testis showed positive staining, but 4 of 8 samples from boys with undescended testis stained positive for AR. Androgen receptor mRNA transcript levels were approximately 10 times lower in cremaster muscles of boys with descended testis compared with those in boys with undescended testis. CONCLUSIONS: Despite similar serum hormone levels, more AR expression in cremaster muscles associated with undescended testis might represent evidence of being subjected to a lesser degree of androgenic effects.