Clinical and genetic characterization of children with cubilin variants.

BACKGROUND: Cubilin is one of the receptor proteins responsible for reabsorption of albumin in proximal tubules and is encoded by the CUBN gene. We aimed to evaluate clinical and genetic characterization of six patients with proteinuria who had CUBN mutations. METHODS: Patients' characteristics, serum creatinine, albumin, vitamin B12 levels, urine analysis, spot urine protein/creatinine, microalbumin/creatinine, beta-2 microglobulin/creatinine ratios, estimated glomerular filtration rates (eGFR), treatments, kidney biopsies, and genetic analyses were evaluated. RESULTS: Six patients (2 female, 4 male) with an incidental finding of proteinuria were evaluated. Mean admission age and follow-up time were 7.3 ± 2.9 and 6.5 ± 5.6 years, respectively. Serum albumin, creatinine, and eGFR were normal; urine analysis revealed no hematuria, and C3, C4, ANA, and anti-DNA were negative; kidney ultrasonography was normal for all patients. Urine protein/creatinine was 0.9 ± 0.3 mg/mg, and microalbumin was high in all patients. Serum vitamin B12 was low in two patients and normal in four. Kidney biopsy was performed in four patients, three demonstrated normal light microscopy, and there was one focal segmental glomerulosclerosis (FSGS). Genetic tests revealed four homozygous and two compound heterozygous mutations in the C-terminal part of cubilin. All patients had normal eGFR and still had non-nephrotic range proteinuria at last visit. CONCLUSIONS: CUBN gene mutations should be considered in patients with isolated non-nephrotic range proteinuria and normal kidney function. Diagnosing these patients, who are thought to have a better prognosis, is important in terms of avoiding unnecessary treatment and predicting prognosis. CUBN gene mutations may also present as FSGS which extends the spectrum of renal manifestation of these patients. A higher resolution version of the Graphical abstract is available as Supplementary information.

A New Biomarker on Bone Resorption in Chronic Otitis Media: Osteoprotegerin and NLRP3 Inflammasome Gene Polymorphisms.

Chronic Otitis Media (COM) is a chronic inflammation of the middle ear and mastoid with persistent membrane perforation and hearing loss. Osteoprotegerin (OPG) and NOD like receptor protein 3 (NLRP3) play an important role in bone metabolism. The aim of the study was to investigate the role of OPG and NLRP3 gene polymorphism on ossicular chain resorption in COM. Fourty COM patients and 20 healhty control group were included in the study. While 20 patients underwent ossiculoplasty, 20 patients underwent type 1 tympanoplasty. DNA was isolated from peripheral blood using the DNA kit. OPG gene c.226A > C (p.Thr76Pro) and NLRP3 gene c.592G > A (p. Val198Met) polymorphisms were genotyped using melting curve analysis technique. NLRP3 gene polymorphism were determined in 6 of 20 patients (30%) in ossiculoplasty group, 4 of 20 patients (20%) in type 1 tympanoplasty group and 3 of 20 patients (15%) in control group. OPG gene polymorphism were determined in 5 of 20 patients (25%) in ossiculoplasty group, 3 of 20 patients (15%) in type 1 tympanoplasty group and 1 of 20 patients (5%) in control group, respectively. There was no statistically significant difference between groups regarding to results. Although the difference was not significant NLRP3 and OPG gene polymorphisms were higher in the ossiculoplasty group. Since NLRP3 and OPG gene polymorphisms were determined to be higher numerically in the ossiculoplasty group, OPG and NLRP3 gene regulation system may have an effect on ossicular chain destruction in COM.

Biallelic Mutations in DNAJB11 are Associated with Prenatal Polycystic Kidney Disease in a Turkish Family.

Polycystic kidney disease (PKD) is a life-threatening condition resulting in end-stage renal disease. Two major forms of PKD are defined according to the inheritance pattern. Autosomal dominant PKD (ADPKD) is characterized by renal cysts, where nearly half of the patients suffers from renal failure in the 7th decade of life. Autosomal recessive PKD (ARPKD) is a rarer and more severe form presenting in childhood. Whole-exome sequencing (WES) analyses was performed to investigate molecular causes of the disease in the fetus. In this study, we present 2 fetuses prenatally diagnosed with PKD in a consanguineous family. WES analysis of the second fetus revealed a homozygous variant (c.740+1G>A) in DNAJB11 which is related to ADPKD. This study reveals that DNAJB11 biallelic mutations may cause an antenatal severe form of ARPKD and contributes to understanding the DNAJB11-related ADPKD phenotype. The possibility of ARPKD due to biallelic mutations in ADPKD genes should be considered in genetic counseling.

Secondary findings in 622 Turkish clinical exome sequencing data.

CES (Clinical Exome Sequencing) is a method that we use to diagnose rare diseases with nonspesific clinical features. Besides primary indication for testing genetic information may be detected about diseases which have not yet emerged. ACMG guidelines recommend to report pathogenic variations in medically actionable 59 genes. In this study we evaluated CES data of 622 cases which were tested for various indications. According to ACMG recommendations 59 genes were screened for reportable variations. The detected variations were reviewed using distinct databases and ACMG variation classification guidelines. Among 622 cases 13 (2.1%) had reportable variations including oncogenetic, cardiogenetic disorders, and malignant hyperthermia susceptibility-related genes. In 15 cases (2.4%) heterozygous pathogenic and likely pathogenic variations were detected in genes showing autosomal recessive inheritance. Ten novel variations causing truncated protein or splicing defect were reported. We detected 11 variations having conflicting interpretations in databases and 30 novel variations, predicted as likely pathogenic via insilico analysis tools which further evaluations are needed. As to our knowledge this is the first study investigating secondary findings in Turkish population. To extract the information that may lead to prevent severe morbidities and mortalities from big data is a valuable and lifesaving effort. Results of this study will contrbute to existing knowledge about secondary findings in exome sequencing and will be a pioneer for studies in Turkish population.

The Spectrum of Low-Density Lipoprotein Receptor Mutations in a Large Turkish Cohort of Patients with Familial Hypercholesterolemia.

Background: Monogenic hypercholesterolemia with Mendelian inheritance is a heterogeneous group of diseases that are characterized by elevated plasma low-density lipoprotein cholesterol (LDL-C) levels, and the most common form of this disorder is autosomal-dominant familial hypercholesterolemia (FH). Methods: A total of 104 index cases with the clinical diagnosis of FH were included in this study. Low-density lipoprotein receptor (LDLR) was sequenced using the Sanger sequencing method. Results: Pathogenic/likely pathogenic variants were detected in LDLR in 55 of the 104 cases (mutation detection rate = 52.8%). Thirty different variants were detected in LDLR, three of which were novel. The total cholesterol and LDL-C values of the patients in the group of premature termination codon (PTC) mutation carriers were significantly higher than those of the patients in the group of non-PTC mutation carriers. A total of 87 patients (17 pediatric and 70 adult cases) were diagnosed with cascade genetic screening. Statin treatment was recommended to all 87 patients and was accepted and initiated in 70 of these patients. Conclusions: This study is the largest patient cohort that evaluated FH cases in the Turkish population. Herein, we revealed the LDLR mutation spectrum for a Turkish population and compared the cases in the context of genotype-phenotype correlation. Genetic screening of individuals with suspected FH not only helps to establish their diagnosis, but also facilitates early diagnosis and treatment initiation in other family members through cascade screening.

A large Turkish pedigree with multiple endocrine neoplasia type 1 syndrome carrying a rare mutation: c.1680_1683 del TGAG.

BACKGROUND AND AIMS: Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant syndrome characterized by tumors arising from endocrine glands with no specific genotype-phenotype correlation. Herein, we report the largest Turkish kindred with MEN1 inherited a scarce MEN1 mutation gene. MATERIALS AND METHODS: Sixty-four year-old man, referred to our gastroenterology outpatient clinic for evaluation of pancreatic mass lesion, was diagnosed with MEN1-syndrome after endoscopic ultrasound guided sampling of the mass revealing pancreatic neuroendocrine tumor (pNET), and accompanying primary hyperparathyroidism (PHPT) and pituitary tumor. Genetic analysis by whole gene Sanger sequencing of MEN1 gene identified a frame-shift mutation in exon 10 (c.1680_1683delTGAG). All the relatives of the index case were proposed for clinical and genetic evaluation for MEN1-syndrome. RESULTS: Of the 25 relatives of the index case, 17 were diagnosed MEN1-syndrome. Eighteen members among all relatives consented to genetic analysis and 11 had the same mutation as the index case. All the mutation positive members had MEN1, while none of mutation negative subjects had any sign of MEN1-syndrome. The frequencies of PHPT, pNET and pituitary tumors in this kindred were 94.1% (16/17), 29.4% (5/17) and 29.4% (5/17) respectively. CONCLUSION: We report rare MEN1 gene mutation which was descibed in a single sporadic patient before. It inherited in at least three generations of a large family, which has proven strong dominant effect on MEN1 phenotype. Further researches may be conducted to clarify potential candidacy of this mutation, as a hotspot for MEN1 patients, especially in Turkish population.

Novel mutations and deletions in cystic fibrosis in a tertiary cystic fibrosis center in Istanbul.

BACKGROUND: Cystic fibrosis (CF) genotyping has garnered increased attention since the discovery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in 1989 led to the identification of over 1700 mutations on chromosome 7. Yet, little is known about the genetic profile of CF patients in Turkey. This study sought to determine the mutation distribution among CF patients seeking care at Marmara University. METHODS: Two hundred fifty previously diagnosed CF patients were included in the study. CFTR gene exons 1 to 27 were amplified by a polymerase chain reaction and whole DNA sequencing was performed. Duplications and deletions were investigated by the multiplex ligation-dependent probe amplification (MLPA) technique in patients with one or two unidentified mutations in sequence analysis. RESULTS: CFTR mutation analysis revealed 80 mutations and five large deletions were present in our study population. The five most common mutations were (delta) F508 (c.1521-1523delCTT) (28.4%), 1677delTA (c.1545-1546delTA) (6.4%), 2789 + 5G- > A (c.2657 + 5G > A) (5.8%), N1303K (c.3909C > G) (2.4%), and c.2183AA- > G (c.2051-2052delAAinsG) (4.0%). Large deletions were found in 16 patients. Four novel mutations and two novel deletions were detected in this study. CONCLUSIONS: We have identified four novel mutations and two novel deletions using next-generation DNA sequencing and the MLPA technique and obtained an overall mutation detection rate of 91.4%. Detection of novel variants in CF patients will assist in genetic counseling and in determining appropriate patients for new therapies.

Association between occurrence of ossicular chain defect and osteoprotegerin gene expression in patients with chronic otitis media.

OBJECTIVE: Chronic otitis media (COM) is an important debilitating public problem causing hearing loss due to irreversible resorption of the ossicular chain. Activation of osteoprotegerin (OPG) during an acute attack of COM prevents bone resorption.The aim of the study was to investigate the role of OPG gene expression level on ossicular chain resorption in chronic otitis media. MATERIALS AND METHODS: Fifty operated COM patients were included in the study. While 20 patients underwent ossiculoplasty, 30 patients underwent type 1 tympanoplasty. For RNA isolation and OPG gene expression analysis, middle ear swabs were taken from nasopharynx in the ostium of the Eustachian tube. RNA was isolated with mRNA easy kit and kept at - 85 °C till the cDNA and expression analysis. Expression levels were analyzed with real-time quantitative PCR in comparison with PDGB gene expression level as an internal control. RESULTS: Sample Cq measurements of type 1 tympanoplasty group were higher than Cq measurements of the internal control group (p = 0.027; p < 0.05). In contrast, there was no statistically significant difference between sample Cq measurements of ossiculoplasty group and Cq measurements of the internal control group (p = 0.293; p > 0.05). CONCLUSION: Since OPG gene expression level was significantly higher in type 1 tympanoplasty group, OPG gene regulation system may have an effect on ossicular chain destruction in COM.

Challenges in the treatment of fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva (FOP), is a rare autosomal dominant connective tissue disease with a prevalence of 1 in 2 million. It is characterized by congenital foot deformities and multiple heterotopic ossifications in fibrous tissue. It usually starts with painful soft tissue swellings occurring with attacks at the ages of three or four. The attacks develop spontaneously or after minor trauma, and gradually turn into heterotopic ossifications that cause joint limitations, growth defects, skeletal deformities and chronic pain. The average life expectancy is forthy, and most of the patients are lost due to pulmonary complications. FOP is often misdiagnosed as fibromatosis, desmoid tumour or cancer, bunion, myositis, arthritis and rheumatic diseases. After clinical suspicion, confirmatory genetic analysis should be used for the diagnosis. The treatment of FOP is currently supportive. An effective, proven method has not yet been established. Herein, we present an 18-year-old female patient with FOP who underwent different treatment modalities in a 5-year period. This case-based review reveals all available treatment approaches with at least 6-month follow-up for FOP in the literature.

A Rare Reason of Ileus in Renal Transplant Patients With Peritoneal Dialysis History: Encapsulated Peritoneal Sclerosis.

Encapsulating peritoneal sclerosis is a rare complication of long-term peritoneal dialysis ranging from moderate inflammation of peritoneal structures to severe sclerosing peritonitis and encapsulating peritoneal sclerosis. Complicated it, ileus may occur during or after peritoneal dialysis treatment or after kidney transplant. We sought to evaluate 3 posttransplant encapsulating peritoneal sclerosis through clinical presentation, radiologic findings, and outcomes. We analyzed 3 renal transplant patients with symptoms of encapsulating peritoneal sclerosis admitted posttransplant to our hospital with ileus between 2012 and 2013. Conservative treatment was applied to the patients whenever necessary to avoid surgery. One patient improved with medical therapy. Surgical treatment was delayed and we decided it as a last resort, in 2 cases with no response to conservative treatment for a long time. Finally, patients with peritoneal dialysis history should be searched carefully before renal transplant for intermittent bowel obstruction story.

The impact of preoperative immunonutrition and other nutrition models on tumor infiltrative lymphocytes in colorectal cancer patients.

AIM: The importance of the alteration of tumor infiltrative lymphocytes (CD4(+), CD8(+), CD16(+), and CD56(+)) in colorectal cancer prognosis is well known. In this study, we analyzed the effect of preoperative immunonutrition and different nutritional models on the clinical condition of colorectal cancer patients. METHODS: Twenty-eight colorectal cancer patients were grouped into 4 groups according to their nutrition regimens randomly and were given immunonutrition (IMN), standard enteral (SE), total parental nutrition (TPN), and normal nutrition (NN) regimens, all of which contained the same calorie-nitrogen content within a 7-day preoperative period. All patients had an endoscopic biopsy before and after the regimen, and the lymphocyte population infiltrating mucosal parts of the resected tumor tissue were evaluated. Immunohistochemical analysis of the tissue specimens was performed by staining with antihuman CD4(+), CD8(+), CD16(+), and CD56(+) antibodies. RESULTS: After nutrition, there were significant increases in each of the 4 groups of CD4(+) and CD8(+) cells within the tumor. Comparing the rates of augmentation, the increased rates of the CD8(+) cells infiltrating the tumor after nutrition in the patients who were fed with IMN were significantly more than the ones in other groups (P = .01). CD16(+) cell infiltration was significantly higher in all groups except the SE and IMN groups. The SE group had increased CD56(+) cell infiltration compared with the other groups. CONCLUSIONS: In the colorectal cancer patients who had nutrition in the 7-day preoperative period, except for the SE nutrition group, there were significant increases of infiltration of CD56(+) cells at the mucosal part of the tumor tissue within the CD4(+) and CD8(+) cell population. When postnutrition values were compared, there was a marked increase of CD8(+) cells in the IMN group.

Elective and emergency surgery in chronic hemodialysis patients.

PURPOSE: Aim of this study was to report our experience in elective and emergency surgery on chronic hemodialysis (CH) patients for end-stage renal disease (ESRD). METHODS: All patients on CH for ESRD who underwent various surgical procedures in our unit within the past 9-year period (2001-2010) were included in this study. These patients were divided into two groups according to the type of surgery performed: elective or emergency. Demographic data, indications for surgery, primary causes of ESRD, surgical procedures, postoperative complications, and mortality rates were studied. RESULTS: Of 130 patients, 121 underwent elective surgery while 10 were addressed for emergency operation. In the elective surgery group, the most common diseases were secondary hyperparathyroidism, kidney diseases, cholelithiasis, and diabetic foot gangrene. Complications occurred in nine patients (morbidity rate, 7%) and only one patient died (mortality rate, 0.8%). In the emergency surgery group, the most common diseases were diabetic foot gangrene and obstructed sigmoid colon cancer. In this group, complications occurred in seven patients (total morbidity rate, 70%) and two patients died (mortality rate, 20%). CONCLUSIONS: Elective surgery in patients on CH for ESRD can be performed with acceptable surgical risks provided careful preoperative preparation, intraoperative, and postoperative precautions are taken.