Clinical, biochemical, and molecular insights into Cerebrotendinous Xanthomatosis: A nationwide study of 100 Turkish individuals.

OBJECTIVE: Cerebrotendinous xanthomatosis (CTX) is an inherited metabolic disorder characterized by progressive neurologic and extraneurologic findings. The aim of this retrospective, descriptive study was to explore the time of presentation and diagnosis, and to expand the phenotype and genotype of CTX, based on a nationwide and comprehensive series of patients in Turkey. METHODS: The demographic, clinical, biochemical and genotypic characteristics of the CTX patients were reviewed. Data on molecular analysis, age of onset and diagnosis, diagnostic delay, neurologic and extraneurologic symptomatology, results of plasma cholestanol levels, brain magnetic resonance imaging and electromyography at the time of diagnosis were reviewed. RESULTS: 100 confirmed CTX patients from 72 families were included. The mean age at diagnosis was 28.16 ± 14.28 years, and diagnostic delay was 18.39 ± 13.71 years. 36 patients were diagnosed in childhood. Frequency of intention tremor (p = 0.069), peripheral neuropathy (p = 0.234) and psychiatric manifestations (p = 0.396) did not differ between two groups, demonstrating the high rate in pediatric patients. Three adult patients showed a milder phenotype without neurologic involvement. Seven patients had normal plasma cholestanol levels despite neurological impairment. Sequencing of the CYP27A1 gene revealed 25 different variants, with a novel c.671_672del variant not previously described in literature. CONCLUSION: Based on the observations of this Turkish CTX cohort, it is emphasized that the true prevalence of CTX is probably underestimated and that it has a wide spectrum of clinical phenotypes even without neurological impairment. In children, abnormal cerebellar findings, peripheral neuropathy and psychiatric findings associated with intellectual disability have been suggested as warning signs to avoid diagnostic delay. In cases of clinical suspicion, molecular analysis is recommended despite normal plasma cholestanol levels, as severe neurologic involvement may occur in CTX patients without elevated cholestanol levels.

Refeeding Syndrome Developed in a Patient With Kwashiorkor Can Mimic Findings of Mitochondrial Disorder.

Kwashiorkor is a serious nutritional disease. The 7-month-old male patient presented with severe metabolic acidosis and elevated liver enzymes. His condition was similar to fatty acid oxidation defect. He was taken to the hospital on the previous day with complaints of poor sucking and difficulty breathing. Treatment of upper respiratory tract infection was provided and then he returned to his home. He was cyanotic in bed after 12 hours. The patient, who was taken to the hospital unconscious and not fed for 12 hours, was not given any food orally in the first health center. Until laboratory tests are done, only iv electrolyte and a fluid containing dextrose were given. When the laboratory results were found to be significantly pathological, he was urgently referred to our hospital 4 hours after the admission. The content of the iv treatment applied at the time of referral was not clearly written. Low electrolytes, uric acid, liver enzymes, urea and creatinine elevation were detected at an outer center. Ketosis, lactic acidosis and dibasic aciduria were detected in urine organic acid analysis. He was diagnosed with Kwashiorkor and refeeding syndrome according to the clinical and laboratory findings. His complaints improved with appropriate treatment.

As a Failure to Follow Basic Medical Rules for a Sample, Has a Costly Diagnosis of a Zoonosis.

Cat-scratch disease can be transmitted from cats and dogs in winter. It is usually self-limited and caused by Bartonella henselae. It may cause serious symptoms, including neurological findings, especially in immune-deficient patients. A female patient was referred to our outpatient clinic at the age of 3 years and 10 months with a preliminary diagnosis of neurodegenerative metabolic disease. Her complaints began after a stray cat scratched her. We found out that the hospital to which she was admitted provided only local wound care due to her history of contact with a cat and that she was vaccinated against rabies. Her body temperature increased, her neck lymph nodes became swollen, and she developed otitis and mastoiditis after 1 month. Additionally, we discovered that she had deteriorated in her walking ability after 6 weeks and developed hand tremors after 10 weeks. It was discovered that previous centers to which the patient applied did not question cat contact. All metabolic tests performed for the differential diagnosis of last admission findings were considered nonspecific. Considering cat-scratch disease due to her clinical history, she was referred to the pediatric infection unit for a Bartonella henselae test, and the test result was 1/256 positive. Failure to follow basic medical rules might be costly in diagnosis and treatment. Cat scratch disease is a zoonosis and a major public health problem. In differential diagnosis, these medical procedures should always be considered before rare metabolic diseases.

Interictal epileptiform discharges on electroencephalography in children with methylenetetrahydrofolate reductase (MTHFR) polymorphisms.

OBJECTIVE: Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism. MTHFR C677T and A1298C polymorphisms are best-defined variants of MTHFR that were reported to be associated with epilepsy development. The aim of the study was to determine the incidence of interictal epileptiform discharges on electroencephalography (EEG) in asymptomatic children with C677T and A1298C polymorphisms who had no history of seizure. METHODS: Children with MTHFR C677T or A1298C polymorphisms who had normal neurological examination without a history of seizure were included in the study. Blood samples for serum folate, vitamin B12, and homocysteine levels were analyzed. Sleep and awake electroencephalograms (EEG) were recorded. RESULTS: A total of 102 children (50 girls and 52 boys) with a mean age of 59.4 ± 58.7 months were included in the study. Interictal epileptiform EEG discharges were detected in 3 children (2.9%). CONCLUSION: There was no increase in the prevalence of interictal epileptiform discharges in seizure-free and asymptomatic children with MTHFR C677T and A1298C polymorphisms.

Sub-seasonal Levee Deformation Observed Using Satellite Radar Interferometry to Enhance Flood Protection.

Levees are critical in providing protection against catastrophic flood events, and thus require continuous monitoring. Current levee inspection methods rely on limited information obtained by visual inspection, resulting in infrequent, localized, mostly qualitative and subjective assessments. This hampers the timely detection of problematic locations and the assessment of levee safety in general. Satellite radar interferometry yields weekly observations of levee conditions with high precision which complement current inspection methods. Here we show that levees are susceptible to short-term swelling and shrinkage associated with meteorological conditions, and assess how deformations can be related to the geohydrological properties and the safety of the levee. Our findings allow to understand the sub-seasonal behaviour of the levee in greater detail and to predict swelling and shrinkage due to variation of the loading conditions. This will improve the detection of anomalous levee responses which contributes to the development of reliable early warning methods using continuous deformation monitoring.

Retrospective approach to methylenetetrahydrofolate reductase mutations in children.

Methylenetetrahydrofolate reductase reduces methyltetrahydrofolate, a cosubstrate in the remethylation of homocysteine, from methylenetetrahydrofolate. Congenital defects, hematologic tumors, and intrauterine growth retardation can occur during childhood. This study evaluated clinical and laboratory treatment approaches in children diagnosed with methylenetetrahydrofolate reductase mutations. Our group included 23 boys and 14 girls, aged 103.4 ± 70.8 months S.D. Clinical findings of patients and homocysteine, vitamin B12, folate, hemogram, electroencephalography, cranial magnetic resonance imaging, and echocardiography data were evaluated in terms of treatment approach. Our patients' findings included vitamin B12 at 400.4 ± 224.6 pg/mL S.D. (normal range, 300-700 pg/mL), folate at 10.1 ± 4.5 ng/mL S.D. (normal range, 1.8-9 ng/mL), and homocysteine at 8.4 ± 4.7 µmol/L S.D. (normal range, 5.5-17 µmol/L). Eighty-eight percent of patients demonstrated clinical findings. In comparisons involving categorical variables between groups, χ(2) tests were used. No relationship was evident between mutation type, laboratory data, and clinical severity. All mothers who had MTHFR mutations and had babies with sacral dimples had taken folate supplements during pregnancy. To avoid the risk of neural tube defects, pregnant women with a MTHFR mutation may require higher than normally recommended doses of folic acid supplementation for optimum health.

Monitoring tyrosinaemia type I: Blood spot test for nitisinone (NTBC).

BACKGROUND: Quantification of nitisinone, 2-(nitro-4-trifluoromethylbenzoyl)1,3-cyclohexanedione (NTBC) has been repeatedly described. Nevertheless monitoring of NTBC has not yet become part of routine therapy surveillance in tyrosinaemia type I (OMIM 276700). We developed a blood spot test to facilitate collection and transport of samples. Furthermore, the test material can be used for determination of other parameters like tyrosine and succinylacetone. METHOD: For quantification of NTBC in blood spots filter paper discs of 3.2mm diameter were extracted with 150 µL methanol containing mesotrione as internal standard (IS). Analysis was done by UPLC-MS/MS on a Xevo mass spectrometer (ESI+), (MRM). Parent ions were 330.05 for NTBC and 340.05 for IS, daughter ions were m/z 217.95 and m/z 125.95 for NTBC, and m/z 227.95 and m/z 103.95 for IS. RESULTS: The calibration curve for NTBC in blood spots was linear from 0.1 µmol/L to 100 µmol/L. Recovery exceeded 73.1%, CV intraday and interday were below 9.6%. Instrumental run time was 2.5 min. Sensitivity of the method was 0.1 µmol/L. NTBC concentrations in plasma were higher than in blood spots by a factor of 1.56 ± 0.13. CONCLUSION: As demonstrated in patients with tyrosinaemia type I quantification of NTBC by UPLC-MS/MS in blood spots is feasible and gives valuable information for monitoring NTBC treatment.

Molecular genetics and impact of residual in vitro phenylalanine hydroxylase activity on tetrahydrobiopterin responsiveness in Turkish PKU population.

BACKGROUND: The prevalence of phenylalanine hydroxylase (PAH)-deficient phenylketonuria (PKU) in Turkey is high (1 in 6500 births), but data concerning the genotype distribution and impact of the genotype on tetrahydrobiopterin (BH(4)) therapy are scarce. OBJECTIVE: To characterize the phenotypic and genotypic variability in the Turkish PKU population and to correlate it with physiological response to BH(4) challenge. METHODS: We genotyped 588 hyperphenylalaninemic patients and performed a BH(4) loading test (20mg/kg bw) in 462 patients. Residual PAH activity of mutant proteins was calculated from available in vitro expression data. Data were tabulated in the BIOPKU database (www.biopku.org). RESULTS: Eighty-eight mutations were observed, the most common missense mutations being the splice variant c.1066-11G>A (24.6%). Twenty novel mutations were detected (11 missense, 4 splice-site, and 5 deletion/insertions). Two mutations were observed in 540/588 patients (91.8%) but in 9 patients atypical genotypes with >2 mutations were found (8 with p.R155H in cis with another variant) and in 19 patients mutations were found in BH(4)-metabolizing genes. The most common genotype was c.1066-11G>A/c.1066-11G>A (15.5%). Approximately 22% of patients responded to BH(4) challenge. A substantial in vitro residual activity (average >25% of the wild-type enzyme) was associated with response to BH(4). In homozygous genotypes (n=206), both severity of the phenotype (r=0.83) and residual PAH activity (r=0.85) correlate with BH(4) responsiveness. CONCLUSION: Together with the BH(4) challenge, these data enable the genotype-based classification of BH(4) responsiveness and document importance of residual PAH activity. This first report of a large-scale genotype assessment in a population of Turkish PKU patients also documents a high prevalence (47%) of the severe classic phenotype.

Molecular features of 23 patients with glycogen storage disease type III in Turkey: a novel mutation p.R1147G associated with isolated glucosidase deficiency, along with 9 AGL mutations.

Glycogen storage disease type III (GSD III) is an autosomal recessive disorder caused by deficiency in the glycogen debranching enzyme (gene symbol: AGL) with two enzyme activities: transferase and glucosidase. A missense mutation causing isolated glucosidase deficiency has never been reported. In this study, we examined 23 patients of Turkish ancestry and identified a novel missense mutation p.R1147G with isolated glucosidase deficiency, along with nine AGL mutations: six nonsense mutations (p.W373X, p.R595X, p.Q667X, p.Q1205X, p.W1327X and p.Q1376X), one deletion (c.1019delA) and two splicing mutation (c.293+2T>G and c.958+1G>A). As p.R1147G impaired glucosidase activity, but maintained transferase activity in vitro, a 12-year-old girl homozygous for p.R1147G was diagnosed with having isolated glucosidase deficiency. Of nine other mutations, p.W1327X and c.1019delA were recurrent, whereas seven mutations were novel. Six patients with p.W1327X were all from two nearby cities on the East Black Sea and shared the same AGL haplotype, indicating a founder effect in Turkish patients. Patients with the same mutations had identical haplotypes. Our results provide the first comprehensive overview of clinical and molecular features of Turkish GSD III patients and the first description of the missense mutation associated with isolated glucosidase deficiency.