ABSTRACT
BACKGROUND: Bardet-Biedl syndrome (BBS) is a very-rare autosomal recessive genetic disorder with severe multisystem manifestations. Genetic testing plays an important role in the early diagnosis of the disease. In this study, while trying to elucidate the genetic etiology of seven individuals with clinical BBS diagnosis from six different families, we also aimed to examine the distribution of BBS variations in this region of Turkey. METHODS AND MATERIALS: Exome sequencing analysis is performed for clinically diagnosed patients with BBS in the present study followed by parental segregation. The unreported and previously described clinical features are presented. RESULTS: Homozygous variants, four of which are unreported, in BBS-related genes (BBS5 [c.682-2A > G], MKKS [c.775del], BBS7 [c.849+1G > T], BBS9 [c.965G > A], BBS10 [c.145C > T], LZTFL1[c.384G > A]) are detected for all the seven individuals included in the study. The most common clinical finding is polydactyly followed by renal anomalies. The clinical features not previously described are correlated to the unreported variant. CONCLUSIONS: In this study, exome sequencing findings are discussed and four previously unreported disease-associated variants are described including the fifth BBS-implicated LZTFL1 change and possible genotype-phenotype correlation is described.
Subject(s)
Bardet-Biedl Syndrome/genetics , Exome , Adolescent , Bardet-Biedl Syndrome/diagnosis , Child , Child, Preschool , Cohort Studies , Consanguinity , Female , Genetic Association Studies , Homozygote , Humans , Infant , Male , Turkey , Exome SequencingABSTRACT
The aim of this study was to evaluate the maternal and foetal factors affect higher cell-free DNA (cfDNA) levels and to investigate a possible relationship between high cfDNA levels and adverse perinatal outcomes. From a total of 4594 women who underwent non-invasive prenatal testing from January 2016 to March 2018 in our hospital, 112 women had high levels of cfDNA, which was not appropriate for testing. Maternal characteristics and perinatal outcomes were compared between patients with high levels of cfDNA and normal levels of cfDNA. Patients with high levels of cfDNA had greater risks than patients with normal cfDNA levels of pregnancy complications but no statistically significant difference was found. Patients with high cfDNA levels had higher foetal death rates with a statistically significant difference (9.8% versus 1.8%, p = .024). An increase in foetal death could be expected in patients with increased cfDNA levels; therefore, these patients should be carefully followed up during pregnancy.IMPACT STATEMENTWhat's already known about this topic? Most studies about cfDNA levels are focussed on the foetal fraction. There are new arguments about maternal health and cfDNA. It is known that autoimmune diseases as systemic lupus erythematosus (SLE) and maternal obesity increase cell turnover. There are also clinical studies suggesting a relationship between low molecular weight heparin therapy and the amount of cfDNA.What do the results of this study add? This is the first study evaluating the maternal and foetal biological factors affecting cfDNA concentrations and investigating the possible relationship between high cfDNA levels and adverse perinatal outcomes in patients with high levels of cfDNA compared to patients with normal levels of cfDNA. In the present study, it was found that an increase in foetal death could be expected in patients with higher cfDNA levels.What are the implications of these findings for clinical practice and/or further research? If potential effects and underlying causes of increased cfDNA could be explained, cfDNA might be used as a biomarker for adverse perinatal outcomes.
Subject(s)
Cell-Free Nucleic Acids/blood , Pregnancy Complications/blood , Pregnancy Outcome/genetics , Adult , Case-Control Studies , Female , Fetal Death/etiology , Humans , Maternal Health , Maternal Serum Screening Tests , Pregnancy , Risk FactorsABSTRACT
Periodic fever syndromes (PFSs) are a family of clinical disorders, which are characterized by recurrent episodes of fever in the absence of microbial, autoimmune or malign conditions. Most common types of PFSs are associated with four genes: MEFV, MVK, TNFRSF1A and NLRP3. This paper aims to add new data to the genotype-phenotype association of MVK-, TNFRSF-1A- and NLRP3-associated PFSs. A total number of 211 patients were evaluated. Two different approaches were used for the molecular genetic evaluation of MVK-, TNFRSF-1A- and NLRP3-associated PFSs. For the first 147 patients, Sanger sequence analysis of selected exons of MVK, TNFRSF1A and NLRP3 genes was done. For subsequent 64 patients, targeted NGS panel analysis, covering all exons of MVK, TNFRSF1A and NLRP3 genes, was used. A total number of 48 variants were detected. The "variant detection rate in index patients" was higher in the NGS group than Sanger sequencing group (19% vs. 15,1%). For the variant positive patients, a detailed genotype-phenotype table was built. In PFSs, lack of correlation exists between genotype and phenotype in the general population and even within the families. In some cases, mutations behave differently and yield unexpected phenotypes. In this study, we discussed the clinical effects of eight different variants we have detected in the MVK, TNFRSF1A and NLRP3 genes. Four of them were previously identified in patients with PFS. The remaining four were not reported in patients with PFS. Thus, we had to interpret their clinical effects by analysing their frequencies and in silico analysis predictions. We suggest that new studies are needed to evaluate the effects of these variants more clearly. To be able to demonstrate a clearer genotype-phenotype relationship, all PFS-related genes should be analysed together and the possibility of polygenic inheritance should be considered.
Subject(s)
Familial Mediterranean Fever/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Phosphotransferases (Alcohol Group Acceptor)/genetics , Receptors, Tumor Necrosis Factor, Type I/genetics , Exons , Familial Mediterranean Fever/immunology , Familial Mediterranean Fever/pathology , Female , Fever/genetics , Fever/immunology , Fever/pathology , Gene Frequency , Genetic Association Studies , Genetic Predisposition to Disease , Genotype , Humans , Male , Mutation , Pyrin/geneticsABSTRACT
INTRODUCTION: Brain metastasis prevalence is higher in patients with positive epidermal growth factor receptor (EGFR) mutation, anaplastic lymphoma kinase (ALK) and C-ROS oncogene 1 (ROS-1) fusion change in lung adenocarcinoma. OBJECTIVES: The purpose of our study is to investigate the relation between the genetic change type and the initial distant metastasis in stage IV lung adenocarcinoma patients with genetic changes. METHODS: The study was conducted between January 2007 and December 2018 in a retrospective fashion with patients who had lung cancer diagnosed as stage IV adenocarcinoma. The relation between genetic mutation change (EGFR, ALK or ROS-1) and distant metastasis was analysed. RESULTS: A total of 845 patients were included in the study. The median age was 62 (28-88). It was determined that lung and pleura metastases were more frequent at a significant level in patients with positive EGFR mutation (P = 0.032, P = 0.004, respectively). In patients with positive ALK fusion change, pleura metastasis was determined to be more frequent (P = 0.001). Multiple metastases were determined to be significantly more in patients with positive ALK fusion change than single metastasis (P = 0.02). CONCLUSION: In patients with EGFR mutant lung adenocarcinoma, lung and pleura metastasis is more frequent and pleura metastasis is more frequent in ALK positive adenocarcinoma. Additionally, multiple organ metastases are higher in ALK positive lung adenocarcinoma.
Subject(s)
Adenocarcinoma of Lung , Adenocarcinoma , Lung Neoplasms , Adenocarcinoma/genetics , Adenocarcinoma of Lung/genetics , Humans , Lung Neoplasms/genetics , Middle Aged , Mutation , Receptor Protein-Tyrosine Kinases , Retrospective StudiesABSTRACT
Pierson syndrome is characterized by congenital nephrotic syndrome and bilateral microcoria. Genetically, mutations in the LAMB2 gene, which encodes the laminin ß2 chain, lead to this disorder. To date, 98 cases and 50 different mutations have been reported in literature. There are no specific therapies for Pierson syndrome and treatment is supportive. The prognosis is poor because of progressive impairment of renal function and complications of renal failure. We report a novel homozygous mutation (c.1890G>T, p.Q630H) in the LAMB2 gene in a patient with Pierson syndrome who had atypical phenotypic feature such as epidermolysis bullosa.
El síndrome de Pierson se caracteriza por la presencia de síndrome nefrótico congénito y microcoria bilateral. Genéticamente, este trastorno está ocasionado por mutaciones en el gen LAMB2, que codifica la cadena ß2 de la laminina. Hasta la fecha, en la bibliografía se informaron 98 casos y 50 mutaciones diferentes. No existen terapias específicas para el síndrome de Pierson, y el tratamiento es complementario. El pronóstico es malo por la disfunción renal progresiva y las complicaciones de la insuficiencia renal. En este artículo, se informa sobre una mutación homocigota novedosa (c.1890G>C [p.Q630H]) en el gen LAMB2 en una paciente con síndrome de Pierson que tenía un fenotipo atípico, como epidermólisis ampollosa.
Subject(s)
Laminin/genetics , Myasthenic Syndromes, Congenital/diagnosis , Nephrotic Syndrome/diagnosis , Pupil Disorders/diagnosis , Female , Genetic Markers , Homozygote , Humans , Infant , Mutation , Myasthenic Syndromes, Congenital/genetics , Nephrotic Syndrome/genetics , Phenotype , Pupil Disorders/geneticsABSTRACT
Chromosomal microarray (CMA) analysis for discovery of copy number variants (CNVs) is now recommended as a first-line diagnostic tool in patients with unexplained developmental delay/intellectual disability (DD/ID) and autism spectrum disorders. In this study, we present the results of CMA analysis in patients with DD/ID. Of 210 patients, pathogenic CNVs were detected in 26 (12%) and variants of uncertain clinical significance in 36 (17%) children. The diagnosis of well-recognized genetic syndromes was achieved in 12 patients. CMA analysis revealed pathogenic de novo CNVs, such as 11p13 duplication with new clinical features. Our results support the utility of CMA as a routine diagnostic test for unexplained DD/ID.
ABSTRACT
BACKGROUND: Next-generation sequencing (NGS) and discovery of fetal cell-free DNA (cfDNA) in the maternal circulation render possible prenatal screening for trisomy 21 (Down syndrome), trisomy 18, trisomy 13, and sex chromosome aneuploidies. The approach is called "fetal cfDNA screening" and in contrast to noninvasive conventional serum screening, it provides the identification of 98%-99% of fetuses with Down syndrome. METHODS: Retrospective analysis of targeted noninvasive prenatal testing (NIPT) (Clarigo Test) pregnancies with moderate risk, which we have reported between 2016 and 2018 years is presented. Two separate laboratory workflows and NGS platforms are used for the same targeted NIPT analysis. RESULTS: In total, 4,594 pregnant women were investigated. Initial 3,594 cases are studied by MiSeq platform, the last 1,000 cases by NextSeq. Failure rate for MiSeq platform is 10.9% and for NextSeq is 8.7%. Automatically reported cases constitute 75% of the MiSeq group and 87% of the NextSeq group. CONCLUSIONS: Targeted NIPT results suggest that MiSeq platform could be used for NIPT which would be an essential option particularly for laboratories with low sample flow. And, the NextSeq platform has easier wet lab process and also increased success rate in automatic reporting which is suitable for centers with high number of NIPT cases.
Subject(s)
Aneuploidy , Cell-Free Nucleic Acids/analysis , Fetus/metabolism , Genetic Testing/methods , Adolescent , Adult , Cell-Free Nucleic Acids/chemistry , Down Syndrome/genetics , Female , Genetic Counseling , Gestational Age , High-Throughput Nucleotide Sequencing , Humans , Middle Aged , Pregnancy , Prenatal Diagnosis , Retrospective Studies , Sequence Analysis, DNA , Trisomy 13 Syndrome/genetics , Trisomy 18 Syndrome/genetics , Young AdultABSTRACT
El síndrome de Pierson se caracteriza por la presencia de síndrome nefrótico congénito y microcoria bilateral. Genéticamente, este trastorno está ocasionado por mutaciones en el gen LAMB2, que codifica la cadenaß2 de la laminina. Hasta la fecha, en la bibliografía se informaron 98casos y 50mutaciones diferentes. No existen terapias específicas para el síndrome de Pierson, y el tratamiento es complementario. El pronóstico es malo por la disfunción renal progresiva y las complicaciones de la insuficiencia renal. En este artículo, se informa sobre una mutación homocigota novedosa (c.1890G>C [p.Q630H]) en el gen LAMB2 en una paciente con síndrome de Pierson que tenía un fenotipo atípico, como epidermólisis ampollosa.
Pierson syndrome is characterized by congenital nephrotic syndrome and bilateral microcoria. Genetically, mutations in the LAMB2 gene, which encodes the laminin ß2 chain, lead to this disorder. To date, 98 cases and 50 different mutations have been reported in literature. There are no specific therapies for Pierson syndrome and treatment is supportive. The prognosis is poor because of progressive impairment of renal function and complications of renal failure. We report a novel homozygous mutation (c.1890G>T, p.Q630H) in the LAMB2 gene in a patient with Pierson syndrome who had atypical phenotypic feature such as epidermolysis bullosa