Study of obesity associated proopiomelanocortin gene polymorphism: relation to metabolic profile and eating habits in a sample of obese Egyptian children and adolescents

Background: Melanocortinergic system represents a known system involved in the central regulation of body weight with the central proopiomelanocortin [POMC] neurons forming a potent anorexigenic network. Polymorphisms in the POMC gene locus are associated with obesity phenotypes

Aim: To assess the contribution of the POMC gene 9-bp insertional polymorphism in the susceptibility to obesity and its relation to body mass index [BMI] and adiposity-related co-morbidities in obese children and adolescents; as well as binge eating behavior

Patients and methods: Fifty obese children and adolescents with simple obesity were screened for Binge Eating Disorder [BED] by The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition [DSM-5], they were compared to 50 age, sex and pubertal stage-matched non obese controls. Anthropometric measurements, blood pressure, abdominal ultrasound for fatty liver, measurement of fasting lipid profile, fasting insulin, fasting blood glucose and assessment of POMC gene 9-bp insertional polymorphism were done

Results: Obese patients had significantly higher anthropometric measurements, blood pressure percentiles, fasting glucose, fasting insulin, homeostasis model assessment for insulin resistance [HOMA-IR] and fasting lipid profiles, and higher frequency of occurrence of non alcoholic fatty liver disease and BED. Allelic frequencies of POMC gene 9 bp insertional polymorphism were comparable in patients and controls [p= 0.956]. Fasting insulin levels were significantly higher in the heterozygous cases having the polymorphism than in wild homozygous cases; whereas no difference was observed among the controls

Conclusion: This polymorphism was associated with higher fasting insulin levels in the obese patients only. These findings support the hypothesis that the melanocortin pathway may modulate glucose metabolism in obese subjects indicating a possible gene-environment interaction. POMC variant may be involved in the natural history of polygenic obesity, contributing to the link between type 2 diabetes and obesity

Molecular characterization of X chromosome fragility in idiopathic mental retardation

Background: Fragile X syndrome [FXS] is the most common form of inherited mental retardation. Frequency of fragile X syndrome among male siblings and relatives of mentally retarded patients is relatively high. Cytogenetic diagnosis of FXS is unreliable since it is ineffective for the diagnosis of premutated males or females. Proper molecular diagnosis is a pre-requisite for providing proper counseling advice

Subjects and methods: Sixty-four males with idiopathic mental retardation, ranging in age from 4.2 to 19 years [10.92+/- 4.00] were clinically pre-selected, based on scoring protocol comprising eight features of the syndrome, before molecular testing. A rapid polymerase chain reactionbased screening was applied for detection of expanded FMR1 alleles. Samples that did not yield the normal band lengths were subjected to a second PCR screen. The secondary screen utilizes a chimeric primer demonstrating the presence or absence of an expanded allele

Results: Amplification of FMRI gene by PCR of tested patients revealed that 8 cases [12.5%] have full mutation and 6 cases [9.4%] have premutation. A wide range of Fra X-scoring ranging from 1 to 7 features was detected in examined cases. Significant clinical features included large prominent ears, hyperextensibility of joints and macroorchidism in post pubertal males

Conclusions: A simplified checklist of fragile X should be used for patients with idiopathic MR and those patients above score 3 should be tested for FXS. The diagnostic assay may be used as a screening method for fragile X syndrome being rapid and cost effective compared to other techniques. In addition, screening of all relatives of proven patients should be performed to detect clinically unidentified cases for provision of proper counseling and optimal management of detected cases

Genotyping of mannose-binding lectin [MBL2] codon 54 and promoter alleles in Egyptian infants with acute respiratory tract infections

MBL2 gene polymorphisms affect serum concentration of mannose-binding lectin and are associated with infectious conditions. Acute respiratory tract infections are among the most prevalent infections in childhood with the highest incidence among children younger than 2 years. This study aimed at correlation between the occurrence of acute respiratory tract infections and the prevalence of MBL2 gene codon [54] and promoter variants among the Egyptian infants in the study. This case-control study included 25 neonates [0.21 +/- 0.19 months], 25 infants [9.65 +/- 8.5 months] with acute respiratory tract infection and normal control group. CBC, CRP and chest X-ray were done. DNA was extracted from peripheral blood. Genotypes of MBL gene codon 54-exon 1[G54D] were identified by PCR-RFLP analysis. MBL2 promoter genotyping was performed by allele-specific polymorphisms at -550 [H/L] and - 221[X/Y]. Incidence of LX promoter haplotype among the patients was [58%] [p < 0.05]. Homo-zygosity for codon [54] allele A [high expression activity] among patients was [72%] [p > 0.05]. Heterozygote codon 54 A/B genotype appeared more in patients [18%] [p < 0.05]. Mutant genotype [too low expression activity] was more in patients but the difference was insignificant. Collectively the mutant allele [glycine to aspartic acid, allele B] appeared in 28% of patients compared to 20% in control [p > 0.05]. YA/XA heterozygote promoter genotype was more prevalent among patients group [44%] [p < 0.05]. Low-expression promoters [XA/B] and [B/B] appeared more in the patients [20%] compared to [12%] among control group [p > 0.05]. Among ICU neonates, LX promoter was the most prevalent among all grades of respiratory distress [39.13%] followed by LY allele [34.78%]. In the infants group, LY allele was [52.1%] with equal distribution of LY and HY [23.91% each]. Although there is a significantly increased incidence of LX promoter coding for low serum MBL concentrations among the ARTI patients; the YA/XA heterozygote promoter genotype was more prevalent over the homozygote mutant genotype. Also, the heterozygote codon 54 A/B genotype was more prevalent in the group of patients compared to the control. This may be an example of heterosis [heterozygote advantage] which may support the concept of balanced polymorphism

Protein substitution to produce a processed cheese with high branched-chain amino acids of medical and genetic importance

The most important metabolic impairment in patients with advanced liver disease is characterized by low levels of circulating branched chain amino acids [BCAAs]. The etiology of such abnormal amino acid metabolism is multifactorial including protein restricted diet or inadequate nutritional intake as in protein energy malnutrition. Multiple studies report the beneficial effects of BCAAs supplementation to improve plasma amino acids imbalance, several neurologic diseases, protein energy malnutrition, and subsequently the survival rate of cirrhotic patients. In the present study we used a protein substitution technique to synthesize a new processed cheese as a dairy source rich in BCAAs, with low phenylalanine content manufactured from Ras cheese, kariesh cheese, butter oil and phenylalanine-free milk. Chemical composition, amino acids analysis, rheological properties and sensory evaluation were done to all of the cheese samples. L-Phenylalanine was selected to induce hepatic and brain affections in Begg Albino strain c [BALB/c] mice model. Effect of 2.5%, 5% and 10% protein-replacement cheese formulas was evaluated among mice groups including histopathological sections of the liver and brain; colorimetric determination for liver enzymes; serum total and differential cholesterol profile, serum albumin, globulin and total protein along with phenylalanine levels determinations. Analysis of the processed cheese sample with 10% protein substitution revealed that the protein content was 7.42 mg/g [about 50% of the content in the standard processed cheese] while fat content, acidity and moisture were nearly the same. The sensory score for all the formulas ranged from 79-88. Highest content of BCAAs along with least phenylalanine content was attained in the processed cheese with 10% protein substitution. Weight of mice fed on different substitution formulas ranged from 22.8 +/- 2.2-24.66 +/- 2.5 g compared with 17.8 +/- 1.9 g in the untreated diseased mice [P< 0.05]. Serum phenylalanine was 1.822 +/- 0.42 mg/dl in the mice fed on 10% protein substitution formula compared to 6.2 +/- 1.32 mg/dl in the untreated mice [P < 0.01]. There was a highly significant difference [P <0.01] between untreated mice and mice fed on 10% substitution cheese formula as regards the serum protein, Aspartate Transaminase [AST] and Alanine Transaminase [ALT]. The improvement in histopathological findings was more apparent in the mice fed on 10% formula cheese. The manufactured processed cheese with 10% protein substitution was proved to have a more nutritional therapeutic potential that can help in the implementation of dietary management in many medical and genetic disorders with liver and brain affections

Enzymatic preparation of low-phenylalanine Formula derived from skim milk hydrolysate for phenyl ketonuric patients

Phenylketonuria [PKU] is one of the most common inborn errors of amino acids metabolism. WHO guidelines introduced in 1979 and revised 1988 for breast-feeding infants with PKU included a formula containing low amounts of phenylalanine as a part of dietary prescription. Mental retardation can be prevented if PKU is diagnosed in the 1 st three weeks of life and diet therapy started straightaway throughout life and especially in the hyper phenylalaninemic mothers before conception and during pregnancy. The aim of the present study was to synthesize a low-phenylalanine formula suitable to be taken by PKU children, adolescents and the hyperphenylalaninemic mothers. This formula should be of high biological value, taken safely by those patients and to be of low cost. The formula was prepared from skim milk hydrolysate using two proteolytic enzymes. The first was the immobilized purified papain enzyme and the second was the modified protease XXIII prepared from Aspergillus oryzae. The skim milk hydrolysate was adsorbed on barium sulphate or activated carbon for removing phenylalanine. They were applied separately for the purpose of debittering and nutritional value comparison. This skim milk hydrolysate had been supplemented with the amino acids tryptophan, tyrosine, methionine and valine. Beside the comprehensive amino acids analysis [Especially for the free amino acids], this formula was then analyzed for protein, fat, lactose and ash contents as well as microbiological and biological testing on mice. Hyperphenylalaninemia was induced in BALB/c mice model then changes in blood phenylalanine level and weight were scored during the periods of mutagenesis as well as the treatment period compared with the control group. The amino acids analysis showed that phenylalanine was 0.71gm/100 gram protein in the skim milk hydrolysate compared to 3.26gm amino acid/100 gram protein in the skim milk. The level of free phenylalanine decreased from 6.34% [In the skim milk] to 0% after adsorption to barium sulphate and compared to 3.41% after adsorption to activated carbon. The formula adsorbed on barium sulphate, although it is more preserving to the nutritional composition; yet, it is less effective in the debittering effect than that adsorbed on activated carbon. This formula, in addition to being of high nutritional value, it is not expensive since it is obtained from skim milk hydrolysate. From the present study, it could be concluded that: The synthesized low-phenylalanine formula was effective in supplying most of the needed dietary intakes for conditions of hyperphenylalaninemia. The use of the immobilized purified Papain and modified protease XXIII from Aspergillus oryzae in enzymatic hydrolysis of skim milk has been proved to be effective in hydrolysis and emulsification

Williams-beuren syndrome in a boy with Klinefelter syndrome

Williams-Beuren syndrome, now recognized to be caused by a micro deletion of chromosome 7, is a multisystem disorder with mental retardation and characteristic facial features. On the other hand, Klinefelter syndrome [47, XXY] is now appreciated as being the most common single cause of infertility and hypogonadism. We report a boy; 9 years old, from UAE affected by both disorders. The patient had a characteristic dysmorphic facies, mental retardation, cardiovascular affection and dental anomalies together with relatively small penis and testes. The diagnosis was established and confirmed through chromosomal study and FISH analysis

lymphotoxin-alpha gene polymorphism and asthma in Egyptian children

Tumor necrosis factor is a proinflammatory cytokine found in increased concentrations in asthmatic airways. The TNF-alpha [TNFA] and lymphotoxin-alpha [LTA] genes belong to the TNF gene superfamily located within the human major histocompatibility complex on chromosome 6p in a region repeatedly linked to asthma. In this study, we examined 30 asthmatic of average age +/- SD of 8.3 +/- 3.6 y and 28 non-asthmatic Egyptian children. We used the PCR-RFLP analysis to identify the polymorphism +252A>G in intron 1 in lymphotoxin-alpha gene. The frequency of the family history was more common [60%] than isolated asthmatic ones. Asthma was significantly more common in subjects with allele A of the LTA*Ncol polymorphism [55%], rather than allele G [45%]. The LTA*Ncol-A/A genotype [40%] was the preferable genotype to LTA*Ncol-G/A and LTA*Ncol-G/G genotypes. In addition, the severe persistent asthmatic cases were associated with the LTA*Ncol-AA genotype at a frequency of 80%, while the genotype LTA*Ncol-GG are associated with the mildest form of the disease. However, someone could predict the severity of asthma and hence the polymorphism of the LTA*Ncol. More than 93% asthmatic population lived in the randomized areas of Cairo where the air pollution. In conclusion, genotype frequencies for the LTA+252 polymorphisms were significantly different from controls. These findings may have implications for future early intervention studies by helping to identify infants at increased risk for wheezing and childhood asthma