Identification of 16 novel mutations in the argininosuccinate synthetase gene and genotype-phenotype correlation in 38 classical citrullinemia patients

Classical citrullinemia (CTLN1), a rare autosomal recessive disorder, is caused by mutations of the argininosuccinate synthetase (ASS) gene, localized on chromosome 9q34.1. ASS functions as a rate-limiting enzyme in the urea cycle. Previously, we identified 32 mutations in the ASS gene of CTLN1 patients mainly in Japan and the United States, and to date 34 different mutations have been described in 50 families worldwide. In the present study, we report ASS mutations detected in 35 additional CTLN1 families from 11 countries. By analyzing the entire coding sequence and the intron-exon boundaries of the ASS gene using RT-PCR and/or genomic DNA-PCR, we have identified 16 novel mutations (two different 1-bp deletions, a 67-bp insertion, and 13 missense) and have detected 12 known mutations. Altogether, 50 different mutations (seven deletion, three splice site, one duplication, two nonsense, and 37 missense) in 85 CTLN1 families were identified. On the basis of primary sequence comparisons with the crystal structure of E. coli ASS protein, it may be concluded that any of the 37 missense mutations found at 30 different positions led to structural and functional impairments of the human ASS protein. It has been found that three mutations are particularly frequent: IVS6-2A>G in 23 families (Japan: 20 and Korea: three), G390R in 18 families (Turkey: six, U.S.: five, Spain: three, Israel: one, Austria: one, Canada: one, and Bolivia: one), and R304W in 10 families (Japan: nine and Turkey: one). Most mutations of the ASS gene are "private" and are distributed throughout the gene, except for exons 5 and 12-14. It seems that the clinical course of the patients with truncated mutations or the G390R mutation is early-onset/severe. The phenotype of the patients with certain missense mutations (G362V or W179R) is more late-onset/mild. Eight patients with R86H, A118T, R265H, or K310R mutations were adult/late-onset and four of them showed severe symptoms during pregnancy or postpartum. However, it is still difficult to prove the genotype-phenotype correlation, because many patients were compound heterozygotes (with two different mutations), lived in different environments at the time of diagnosis, and/or had several treatment regimes or various knowledge of the disease.     

Adult-onset type II citrullinemia and idiopathic neonatal hepatitis caused by citrin deficiency: involvement of the aspartate glutamate carrier for urea synthesis and maintenance of the urea cycle

Citrin is a mitochondrial aspartate glutamate carrier primarily expressed in the liver, heart, and kidney. We found that adult-onset type II citrullinemia is caused by mutations in the SLC25A13 gene that encodes for citrin. In this report, we describe the frequency of SLC25A13 mutations, the roles of citrin as a member of the urea cycle and as a member of the malate-aspartate shuttle, the relationship between its functions and symptoms of citrin deficiency, and therapeutic issues.     

Meta-Analysis and Systematic Review of Micro- and Macro-Nutrient Intakes and Trajectories of Macro-Nutrient Supply in the Eastern Mediterranean Region

The Eastern Mediterranean Region (EMR) is experiencing a nutrition transition, characterized by the emergence of overnutrition and micro-nutrient deficiencies. No previous study has comparatively examined nutrient intake in adults across countries in the EMR. This review examined the adequacy of nutrients in adults living in the EMR. Moreover, it analyzed the food balance sheets (FBS) for 1961–2018 to identify the trajectory of energy supply from macro-nutrients in the EMR. A systematic search was conducted from January 2012 to September 2020. Only observational studies were retained with a random sampling design. An assessment of the methodological quality was conducted. Levels of nutrient daily intake and their adequacy compared to the daily reference intake of the Institute of Medicine were reported across the region. No studies were identified for half of the region’s countries. Although nutrient energy intake was satisfactory overall, fat and carbohydrate intake were high. Intake of vitamin D, calcium, potassium, zinc, and magnesium were below that recommended. The analysis of the FBS data allowed for the identification of four linear patterns of trajectories, with countries in the EMR best fitting the ‘high-energy-supply from carbohydrate’ group. This systematic review warrants multi-sectorial commitment to optimize nutrient intake.     

Vaccination with chimeric protein induces protection in murine model against ascariasis

An estimated 400 million people are infected by parasites of the genus Ascaris and the existing control measures are inefficient. Vaccine development using B cell antigens is a promising strategy for increased protection against this parasite. The present study aimed at developing a chimeric protein capable of conferring protection against infection by Ascaris sp. For this purpose, we performed B-cell epitope predictions on previously described vaccine candidate proteins from Ascaris suum and the corresponding peptides were used to construct a chimeric protein. Female BALB / c mice were immunized subcutaneously in three doses at 10 day intervals with a vaccine formulation comprised of the chimeric protein together with monophosphoryl lipid A (MPLA). Control groups included protein alone, MPLA, or PBS. After challenge infection, animals vaccinated with chimeric protein plus MPLA showed a reduction of 73.54% of larval load in the lung compared to control group animals. Animals immunized with chimeric protein plus MPLA also display higher IgG response and a reduction in lung inflammation. Our study highlights how chimeric proteins containing more than one B cell epitope can enhance immune protection against helminthic infection and offer new approaches to the development of Ascaris vaccines.     

2,3-Dichloro-5,6-dicyano-1,4-benzoquinone as a redox titrant

An oxidimetric titrant, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in anhydrous acetic acid is used for the semimicro-determination of hydrazine hydrate, phenylhydrazine hydrochloride, isoniazid and iproniazid phosphate in pure forms as well as in some pharmaceutical preparations containing isoniazid and iproniazid phosphate. The end point was detected potentiometrically using a platinum-calomel combination electrode. The results obtained are compared statistically with those obtained by the official methods and they are in good agreement.     

Invasive Breast Carcinoma Tumor Size on Core Needle Biopsy: Analysis of Practice Patterns and Effect on Final Pathologic Tumor Stage

Introduction

In the absence of nodal metastasis, pathologic tumor (pT) size remains one of the most important factors in adjuvant treatment decisions and patient prognosis in breast cancer. The aim of this study was to evaluate the effect of core needle biopsy (CNB) tumor size on final pT stage.

Clinical and biochemical spectrum of metabolic cardiomyopathy in Egyptian children

BackgroundInborn errors of metabolism (IEMs) commonly present with pediatric cardiomyopathy. Identification of the underlying cause is necessary as it may lead to improved outcomes.ObjectivesWe aimed to investigate the diagnostic rate, the clinical, and biochemical spectra of IEMs among Egyptian pediatric patients presenting with cardiomyopathy, and their outcome measures.MethodsWe retrospectively analyzed the clinical, biochemical, and radiological data of 1512 children diagnosed with cardiomyopathy at Cairo University Children''s Hospital over a 5-year duration.ResultsTwo hundred twenty-nine children were clinically suspected as IEMs and underwent metabolic workup. Nineteen different IEMs were confirmed in 57 (24.4%) of the suspected children. Their median age at presentation was 2.6 years and the majority had extra-cardiac manifestations. Hypertrophic cardiomyopathy represented 43/57 (75.4%) of confirmed cases, while dilated cardiomyopathy represented 13/57 (22.8%), and one patient presented with a mixed phenotype. Twenty- six patients (45.6%) survived, while 31 patients (54%) either died or were lost to follow up and assumed deceased.ConclusionsWe developed for the first time a database and a diagnostic scheme for metabolic cardiomyopathies in Egyptian children. With the recent introduction of enzyme replacement therapy, many metabolic disorders became treatable, thus establishing an early and accurate diagnosis is extremely important.     

Platinum-induced ototoxicity in pediatric cancer survivors: GSTP1 c.313A>G variant association

Hearing damage is one of the main toxic effects of platinum compounds, it derives from the irreversible degeneration of hair cells of the ear. Genetic association studies have suggested an association between GSTP1 c.313A>G variant and platinum-induced ototoxicity in childhood cancer survivors. We aimed to detect the frequency of ototoxicity and associated risk factors in survivors of childhood cancer receiving platinum-based chemotherapy and to detect the relation between GSTP1 c.313A>G (rs1695) polymorphisms and ototoxicity. We conducted a cross-sectional study on 64 cancer survivors who received platinum agents (cisplatin and/or carboplatin) at least 2 years after the end of chemotherapy. The patients underwent comprehensive audiological evaluations and genotyping to detect the presence of the GSTP1 c.313A>G polymorphisms. Hearing loss (HL) was identified in 16/64 patients (25%), including 62.5% treated with cisplatin and 37.5% treated with carboplatin. The greater incidence of ototoxicity was found in children treated for osteosarcoma (28.1%) followed by patients with germ cell tumors (25%) and neuroblastoma (21.9%). The AA, AG, and GG types of GSTP1 c.313A>G variant were detected in 84.4%, 9.4%, and 6.3%, respectively, of patients with HL with a significant association between mutant genotype of GSTP1 rs1695 and platinum-induced ototoxicity (P = .035). HL was not significantly associated with the total cumulative dose of cisplatin and carboplatin. GSTP1 c.313A>G variant may increase the risk of HL in pediatric oncology patients treated with cisplatin or carboplatin chemotherapy.