Angiotensin-Converting Enzyme (ACE) level, but not ACE gene polymorphism, is associated with prognosis of COVID-19 infection: Implications for diabetes and hypertension.

BACKGROUND: The renin-angiotensin-aldosterone system was shown to be activated in severe COVID-19 infection. We aimed to investigate the relationship between angiotensin converting enzyme (ACE) levels, ACE gene polymorphism, type 2 diabetes (T2DM), and hypertension (HT) and the prognosis of COVID-19 infection. METHODS: This cross-sectional study analyzed the clinical features of adult patients with SARS-CoV-2 infection. ACE gene analysis and ACE level measurements were performed. The patients were grouped according to ACE gene polymorphism (DD, ID or II), disease severity (mild, moderate, or severe), and the use of dipeptidyl peptidase-4 enzyme inhibitor (DPP4i), ACE-inhibitor (ACEi) or angiotensin receptor blocker (ARB). Intensive care unit (ICU) admissions and mortality were also recorded. RESULTS: A total of 266 patients were enrolled. Gene analysis detected DD polymorphism in the ACE 1 gene in 32.7% (n = 87), ID in 51.5% (n = 137), and II in 15.8% (n = 42) of the patients. ACE gene polymorphisms were not associated with disease severity, ICU admission, or mortality. ACE levels were higher in patients who died (p = 0.004) or were admitted to the ICU (p<0.001) and in those with severe disease compared to cases with mild (p = 0.023) or moderate (p<0.001) disease. HT, T2DM, and ACEi/ARB or DPP4i use were not associated with mortality or ICU admission. ACE levels were similar in patients with or without HT (p = 0.374) and with HT using or not using ACEi/ARB (p = 0.999). They were also similar in patients with and without T2DM (p = 0.062) and in those with and without DPP4i treatment (p = 0.427). ACE level was a weak predictor of mortality but an important predictor of ICU admission. It predicted ICU admission in total (cutoff value >37.092 ng/mL, AUC: 0.775, p<0.001). CONCLUSION: Our findings suggest that higher ACE levels, but not ACE gene polymorphism, ACEi/ARB or DPP4i use, were associated with the prognosis of COVID-19 infection. The presence of HT and T2DM and ACEi/ARB or DPP4i use were not associated with mortality or ICU admission.

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.

Phenotypic and genotypic characteristics of children with Bartter syndrome.

INTRODUCTION: Bartter syndrome (BS) is a group of autosomal-recessive tubular disorders and it is classified into five genetic subtypes. BS can also be classified by phenotype (antenatal, classic). Patients with mutations in the same gene can present different phenotypes. In the present study, target gene sequencing was performed to evaluate the genotype-phenotype relationship. METHODS: Biochemical, clinical and renal ultrasonography results were collected at presentation and the last clinic visit. Genetic analyses were performed. The findings of patients with classical BS (cBS) and antenatal BS (aBS) at presentation and the last visit were compared. RESULTS: Our study included 21 patients (12 female, 57.1%) from 20 families with BS. The median age at diagnosis was 8 months and the median follow-up period was 39 months. The most frequent complaint was growth failure. We have found 18 different types of mutations in four genes, including nine in the CLCNKB gene, seven in the SLCA12A1 gene, one in the KCNJ1 gene and one in the BSND gene. In ten patients, nine different types of CLCNKB gene mutations were detected, five of them were novel. Seven different mutations in the SLC12A1 gene were detected in eight patients, five of them were novel. Compared to patients with aBS and cBS, prematurity was significantly higher in the group with aBS. Nephrocalcinosis was present in only one patient with cBS, all the ten hypercalciuric patients with aBS had nephrocalcinosis at the time of diagnosis and the last visit. The mean height standard deviation score (SDS) of patients with aBS were significantly lower than the cBS group at the time of presentation. The mean weight SDS at the time of presentation was worse in patients with aBS than in patients with cBS. The mean plasma potassium and chloride concentrations were significantly lower in the patients with cBS at the time of diagnosis. CONCLUSIONS: This investigation revealed the mutation characteristics and phenotype-genotype relationship of our patients and provided valuable data for genetic counseling.

Analysis of ACE2 and TMPRSS2 coding variants as a risk factor for SARS-CoV-2 from 946 whole-exome sequencing data in the Turkish population.

Heterogeneity in symptoms associated with COVID-19 in infected patients remains unclear. ACE2 and TMPRSS2 gene variants are considered possible risk factors for COVID-19. In this study, a retrospective comparative genome analysis of the ACE2 and TMPRSS2 variants from 946 whole-exome sequencing data was conducted. Allele frequencies of all variants were calculated and filtered to remove variants with allele frequencies lower than 0.003 and to prioritize functional coding variants. The majority of detected variants were intronic, only two ACE2 and three TMPRSS2 nonsynonymous variants were detected in the analyzed cohort. The main ACE2 variants that putatively have a protective or susceptibility effect on SARS-CoV-2 have not yet been determined in the Turkish population. The Turkish genetic makeup likely lacks any ACE2 variant that increases susceptibility to SARS-CoV-2 infection. TMPRSS2 rs75603675 and rs12329760 variants that were previously defined as common variants that have different allele frequencies among populations and may have a role in SARS-CoV-2 attachment to host cells were determined in the population. Overall, these data will contribute to the formation of a national variation database and may also contribute to further studies of ACE2 and TMPRSS2 in the Turkish population and differences in SARS-CoV-2 infection among other populations.

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.

Molecular Aspects of Distal Kidney Tubular Acidosis in Children, Its Long-Term Outcome, and Relationship with Hyperammonemia.

OBJECTIVE: We aimed to present the characteristics, genetic analysis results, long-term progno- sis of our patients with distal kidney tubular acidosis, and the relationship between hyperam- monemia and distal kidney tubular acidosis. MATERIALS AND METHODS: Biochemical, clinical, and imaging findings were collected at presen- tation and the last clinic visit, and results of the genetic analysis were recorded. RESULTS: Our study included 9 patients (3 female, 33%). The median age at diagnosis was 3 months, and the median follow-up period was 111 months. Height standard deviation scores were less than -2 in 4 (44%) patients at presentation and in 3 (33%) at the last clinic visit. The median estimated glomerular filtration rate was 98 mL/min/1.73 m2 at presentation and 126 mL/min/1.73 m2 at the last clinic visit. We have found 8 different types of mutations of 2 genes, including 6 in the ATP6V0A4 gene, 2 in the SLCA4A1 gene, and 2 of them were novel. At the time of presentation, nephrocalcinosis and hypercalciuria were present in all our patients, but at the last visit, only 1 patient had hypercalciuria. Sensorineural hearing loss was found in 4 of our patients with a mutation in the ATP6V0A4 gene. Serum ammonia levels were found to be high in 3 patients with mutations in the ATP6V0A4 gene. CONCLUSION: Adequate metabolic control is essential for optimal growth and preserved kidney function in distal kidney tubular acidosis patients. Distal kidney tubular acidosis may be associ- ated with hyperammonemia. We recommend keeping potassium levels at high-normal levels to reduce ammonia levels, especially in the absence of acidosis.

Alloreactive memory B cell detection by flow cytometric cross match using polyclonally activated memory B cell culture supernatants.

In addition to alloantibodies, alloreactive memory B cell (mBC) evaluation has a potential for immunological risk assessment during transplantation processes. For the alloreactive mBCs evaluation currently, direct Flow Cytometric (FC) analysis using the HLA tetramer staining is an option. Evaluation of alloantibodies produced by the polyclonally stimulated alloreactive mBCs in in vitro culture system seems to be another useful approach, but this needs further downstream applications. In this study, we investigated the usefulness of the Flow Cytometric Cross Match (FCXM-supernatant) in which in vitro polyclonally activated mBCs culture supernatants and potential donor's lymphocytes being used for the mBC detection. FCXM-supernatant assays were performed between culture supernatants of polyclonally activated mBCs obtained from 4 allosensitized multiparous women and 14 renal transplant patients, and their non-alloimmunized spouses' or donors' lymphocytes, and vice versa. HLA typing was performed by SSP method. Anti-HLA antibodies produced by in vitro activated alloreactive mBCs were also evaluated by the Luminex assays. The success of in vitro polyclonal activation of mBCs was evaluated by a total IgG ELISA test and antibody secreting cell analyses by FC. Donor specific alloreactive mBCs were detected by FCXM-supernatant in 45% of the 18 allosensitized cases. Detection rate was 85% (6 out of 7) in the strongly allosensitized cases. No alloreactive mBCs was detected in control cases without allosensitization. FCXM-supernatant negative results of the allosensitized cases were related to low level of allosensitization and insufficient polyclonal stimulation evaluated by total IgG antibody tests of the supernatants. We herein report a practical methodology for alloreactive mBC detection as a donor specific manner using the FCXM-supernatant assay so that this would easily be transformed into a routine test performed in tissue typing laboratories.

Whole-exome sequencing reveals new potential genes and variants in patients with premature ovarian insufficiency.

PURPOSE: Premature ovarian insufficiency (POI) is a heterogeneous disorder characterized by the cessation of menstrual cycles before the age of 40 years due to the depletion or dysfunction of the ovarian follicles. POI is a highly heterogeneous disease in terms of etiology. The aim of this study is to reveal the genetic etiology in POI patients. METHODS: A total of 35 patients (mean age: 27.2 years) from 28 different families diagnosed with POI were included in the study. Karyotype, FMR1 premutation analysis, single nucleotide polymorphism (SNP) array, and whole-exome sequencing (WES) were conducted to determine the genetic etiology of patients. RESULTS: A total of 35 patients with POI were first evaluated by karyotype analysis, and chromosomal anomaly was detected in three (8.5%) and FMR1 premutation was detected in six patients (17%) from two different families. A total of 29 patients without FMR1 premutation were included in the SNP array analysis, and one patient had a 337-kb deletion in the chromosome 6q26 region including PARK2 gene, which was thought to be associated with POI. Twenty-nine cases included in SNP array analysis were evaluated simultaneously with WES analysis, and genetic variant was detected in 55.1% (16/29). CONCLUSION: In the present study, rare novel variants were identified in genes known to be associated with POI, which contribute to the mutation spectrum. The effects of detected novel genes and variations on different pathways such as gonadal development, meiosis and DNA repair, or metabolism need to be investigated by experimental studies. Molecular etiology allows accurate genetic counseling to the patient and family as well as fertility planning.

Intraoperative Tissue-Immunosuppressive Therapy Reduces Rejection Episodes in Heart Transplant Recipients.

OBJECTIVES: Our study was conducted to determine the effects of intraoperative antithymocyte globulin administration on donor hearts procured after cardiocirculatory death. We evaluated the impact of antithymocyte globulin on graft function and related parameters during isothermic blood cardioplegia. MATERIALS AND METHODS: In this prospective and randomized single center study, 30 patients with orthotropic heart transplant were divided into 2 groups: group 1 included 15 patients who received retrograde antithymocyte globulin infusion via coronary sinus intraoperatively and immediately after organ procurement and group 2 included 15 patients who received traditional antithymocyte globulin infusion after implantation. RESULTS: Study patients had a mean age of 33.8 years (range, 15-56 y). All patients had panel reactive antibody less than 10% except for 3 patients. The cluster of differentiation 3-positive cell count decrease was more than 20%. The inotropic therapy dose required and the myocardial pressure (stiffness) were less for group 1 patients. These patients had less acute rejection episodes than group 2 (0% vs 13.3%; P < .05). CONCLUSIONS: Favorable clinical outcomes were observed in terms of less acute rejection episodes and better graft function at least during the early posttransplant period. Intraoperative antithymocyte globulin treatment may have a preventive effect for acute cellular rejection in heart transplant patients.

Effects of vitamin D receptor gene polymorphisms on the prognosis of COVID-19.

PURPOSE: Vitamin D deficiency has emerged as another potential risk factor for coronavirus disease (COVID-19) due to the immunomodulatory effects of 25 hydroxyvitamin D [25 (OH)D]. Vitamin D receptor (VDR) gene polymorphisms such as Fok I, Bsm I, Apa I, and Taq I are also associated with different courses of viral infections. This study aimed to evaluate the association between the VDR gene polymorphism at Fok I, Taq I, Bsm I, and Apa I genotypes and the prognosis of COVID-19 in respect to vitamin D deficiency. METHODS: Two-hundred ninety-seven patients with COVID-19 were enrolled. Serum 25 (OH)D levels were measured. Four variant regions of the VDR gene, FokI, BsmI, ApaI, and TaqI were determined. RESULTS: Eighty-three percent of subjects had vitamin D deficiency, and 40.7% of the whole group had severe deficiency. Median 25 (OH)D level was 11.97 ng/ml. Vitamin D levels were not related to inflammatory markers, disease severity, admission to intensive care unit (ICU), and mortality. While disease severity was related to Fok I Ff genotype, it was Taq TT genotype for ICU admission. Moreover, the ApaI aa genotype was common among the patients who were died. None of the deceased subjects had the Fok I FF genotype. CONCLUSION: 25 (OH)D levels were not related to the severity and mortality of COVID-19. VDR gene polymorphisms are independently associated with the severity of COVID-19 and the survival of patients.

First Patient Diagnosed as Feingold Syndrome Type 2 with Alport Syndrome and Review of the Current Literature.

Introduction: Feingold syndrome type 2 (FGLDS2) is an ultra-rare genetic disorder characterized by short stature, microcephaly, digital abnormalities, and intellectual disability. Until now, 22 patients have been reported in the literature. FGLDS2 is caused by a germline heterozygous deletion of 13q resulting in haploinsufficiency of the MIR17HG gene. Case report: In the present study, we evaluated clinical, radiological, and genetic analyses of a 10-year-old Turkish-origin girl with short stature, brachydactyly, intellectual disability, hematuria, and proteinuria. Conclusion/Discussion: In the array-CGH analysis, a 15.7-Mb deletion, arr[hg19] 13q22q31.3(78,241,132_93,967,288)×1, was detected, and this alteration was evaluated to be pathogenic. The deletion of this region covering the MIR17HG gene is a potential cause of FGLDS2. Also, at her clinical exome sequencing study, a heterozygous c.2023G>A p.(Gly675Ser) variation was detected in the COL4A5 gene (NM_000495.4) that was likely pathogenic in up-to-date databases. As a result, we report on a patient who has FGLDS2 and Alport syndrome. This is the first report of a Turkish-origin FGLDS2 patient. Reporting new cases expands the range of phenotypes, plays a crucial role in understanding the FGLDS2 pathogenesis, and is important in terms of screening at-risk family members for giving appropriate genetic counseling and preimplantation genetic diagnosis opportunities.

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.

Does Genotype-Phenotype Correlation Exist in Vitamin D-Dependent Rickets Type IA: Report of 13 New Cases and Review of the Literature.

Vitamin D-dependent rickets type IA (VDDR-IA) is caused by biallelic mutations in CYP27B1. Data regarding genotype-phenotype correlation in VDDR-IA are scarce. Here, we aimed to investigate clinical/genotypic features and long-term follow-up of 13 new cases with VDDR-IA and genotype-phenotype correlation of reported cases in the literature. Thirteen patients with VDDR-IA were evaluated. Eight patients had reached their final height at the time of the study and, for whom, long-term outcome data were analyzed. Further, all VDDR-IA patients in the literature (n:183) were analyzed and clinical-genetic features were recorded. The median age of diagnosis was 2.55 ± 1.13 (1.0-12) years. Initial diagnoses before referral to our clinic were nutritional rickets (n:7), hypophosphatemic rickets (n:2), and pseudohypoparathyroidism (n:1). All had biochemical evidence suggestive of VDDR-IA; except one with elevated 1,25(OH)2D3 and another with hyperphosphatemia, in whom pseudohypoparathyroidism was excluded with molecular tests. Combined analyses of our cohort and other series in the literature demonstrated that three most common CYP27B1 mutations are p.F443Pfs*24, c.195 + 2T > G, and p.V88Wfs*71. In Turkish population, p.K192E mutation along with the former two is the most common mutations. Comparison of clinical features demonstrated that c.195 + 2T > G mutation causes the most severe and p.K192E mutation causes the least severe phenotype with respect to age and height at presentation and calcitriol requirement. We found a clear genotype-phenotype correlation in VDDR-IA, notably CYP27B1 intronic c.195 + 2T > G mutation causes a more severe phenotype with lower height SDS at presentation and, higher calcitriol requirement, while less severe phenotype occurs in p.K192E mutation.

Cinacalcet as a First-Line Treatment in Neonatal Severe Hyperparathyroidism Secondary to Calcium Sensing Receptor (CaSR) Mutation.

INTRODUCTION: Neonatal severe hyperparathyroidism (NSHPT) is a rare cause of neonatal hypercalcemia caused by a loss of function mutation in the calcium-sensing receptor (CaSR). Hypercalcemia in NSHPT can be life-threatening. Maintenance of serum calcium within a safe range is the primary goal of treatment through hydration, forced diuresis, and bisphosphonate treatment, nevertheless most cases require parathyroidectomy. We report a case with NSHPT diagnosed on the first day of life (DoL) and successfully treated with cinacalcet as the first-line treatment from the 2nd DoL up to the age of 18 months. CASE REPORT: A full-term baby evaluated for weight loss at postnatal 14th hour and found to have hypercalcemia (14.4 mg/dL, reference range [RR]: 8.0-11.3). Despite hydration and diuresis, hypercalcemia persisted. Further evaluation revealed a parathyroid hormone (PTH) level of 1,493 pg/mL (RR: 15-65) and urine Ca/Cr of 0.09 mg/mg (RR: 0.03-0.81). Cinacalcet treatment was initiated on the 2nd DoL with the diagnosis of NSHPT due to hypocalciuric hypercalcemia and elevated PTH level. Ca levels decreased to normal levels on the 7th DoL. She was discharged from hospital at postnatal day 15 on cinacalcet treatment and still continued at 18 months of age. Sequencing of CaSR revealed a novel homozygous c.1836G>A (p.G613E) mutation in the patient, for which the parents and sister were heterozygous. CONCLUSION: This case represents the youngest age at cinacalcet initiation and the longest duration without parathyroidectomy in a homozygous NSHPT and demonstrates that cinacalcet is an effective first-line treatment in patients who are responsive to this treatment modality and allows avoiding/delay in surgical intervention in NSHPT.

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.

A Rare Cause of Hypophosphatemia: Raine Syndrome Changing Clinical Features with Age.

Raine Syndrome (RS) is caused by biallelic loss-of-function mutations in FAM20C gene and characterized by hypophosphatemia, typical facial and skeletal features. Subperiosteal bone formation and generalized osteosclerosis are the most common radiological findings. Here we present a new case with RS. A 9-month-old male patient on a home-type ventilator was referred for hypophosphatemia. He was born with a weight of 3800 g to non-consanguineous parents. Prenatal ultrasound had demonstrated nasal bone agenesis. A large anterior fontanel, frontal bossing, exophthalmos, hypoplastic nose, high arched palate, low set ears, triangular mouth, and corneal opacification were detected on physical examination. Serial skeletal X-rays revealed diffuse osteosclerosis at birth which was gradually decreased by the age of 5 months with subperiosteal undermineralized bone formation and medullary space of long bone could be distinguishable with bone-within-a-bone appearance. At 9 months of age, hand X-ray revealed cupping of the ulna with loose radial bone margin with minimal fraying and osteopenia. Cranial computed tomography scan showed bilateral periventricular calcification and hydrocephalus in progress. The clinical, laboratory, and radiological examinations were consistent with RS. Molecular analyses revealed a compound heterozygous mutation in FAM20C gene (a known pathogenic mutation, c.1645C > T, p.Arg549Trp; and a novel c.863 + 5 G > C variant). The patient died due to respiratory failure at 17 months of age. This case allowed us to demonstrate natural progression of skeletal features in RS. Furthermore, we have described a novel FAM20C variant causing RS. Previous literature on RS is also reviewed.

Fibrodysplasia ossificans progressiva: lessons learned from a rare disease.

PURPOSE OF REVIEW: Fibrodysplasia ossificans progressiva (FOP) is an extremely rare and severely disabling autosomal dominant disease that is yet to be clearly understood. The purpose of this review is to present recent literature on pathophysiology, clinical features, diagnosis and treatment of FOP. RECENT FINDINGS: FOP is characterized by congenital great toe deformity and progressive heterotopic ossifications in connective tissue. Heterotopic ossifications occur after painful flare-ups that can arise spontaneously or can be triggered by minor trauma. Each flare-up ultimately causes restriction of related-joint, and along with the others eventually leads to immobility. Death is usually caused by pulmonary complications because of chest wall involvement. The causative gene of FOP is activin A receptor type 1 (ACVR1), a bone morphogenetic protein-signalling component, which normally acts to inhibit osteoblastogenesis. The treatment of FOP is still preventive and supportive. SUMMARY: Although there are still gaps in the underlying mechanism of FOP, effective treatment options, such as potential pharmacologic targets and cell-based therapies are promising for the future. Some of these were tested without a clinical trial setting, and are currently in the process of evidence-based research.

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.