Thalassemia — From Genotype to Phenotype

Thalassemia encompasses serious diseases with complex pathophysiology that is difficult to explain since it is considered a group of defects with similar clinical effects, still not a single disorder

Screening of dystrophin gene deletions in Egyptian patients with DMD/BMD muscular dystrophies

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are allelic disorders caused by mutations within the dystrophin gene. Our study has identified 100 Egyptian families collected from the Human Genetics Clinic, National Research Center, Cairo. All cases were subjected to complete clinical evaluation pedigree analysis, electromyography studies, estimation of serum creatine phosphokinase enzyme (CPK) levels and DNA analysis. Multiplex PCR using 18 pairs of specific primers were used for screening of deletion mutations within the dystrophin gene. A frequency of 55% of deletions were found among the families. Sixty per cent of detected deletions involved multiple exons spanning the major or the minor hot spot of the dystrophin gene. The remainder 40% involved single exon deletions, which mainly involved exon 45. Comparing these findings with frequencies of other countries it was found that our figures fall within the reported range of 40%-60% for deletions. The distribution of deletions in our study and other different studies was variable and specific ethnic differences do not apparently account for specific deletions. In addition this study concluded that employment of the 18 exon analysis is a cost effective and a highly accurate (97% detection rate) method to be considered when planning to launch a nationwide program

Early-infantile onset epilepsy and developmental delay caused by bi-allelic GAD1 variants.

Gamma-aminobutyric acid (GABA) and glutamate are the most abundant amino acid neurotransmitters in the brain. GABA, an inhibitory neurotransmitter, is synthesized by glutamic acid decarboxylase (GAD). Its predominant isoform GAD67, contributes up to ∼90% of base-level GABA in the CNS, and is encoded by the GAD1 gene. Disruption of GAD1 results in an imbalance of inhibitory and excitatory neurotransmitters, and as Gad1-/- mice die neonatally of severe cleft palate, it has not been possible to determine any potential neurological dysfunction. Furthermore, little is known about the consequence of GAD1 disruption in humans. Here we present six affected individuals from six unrelated families, carrying bi-allelic GAD1 variants, presenting with developmental and epileptic encephalopathy, characterized by early-infantile onset epilepsy and hypotonia with additional variable non-CNS manifestations such as skeletal abnormalities, dysmorphic features and cleft palate. Our findings highlight an important role for GAD1 in seizure induction, neuronal and extraneuronal development, and introduce GAD1 as a new gene associated with developmental and epileptic encephalopathy

Are single nucleotide polymorphisms rs7903146 and rs12255372 in transcription factor 7-like 2 gene associated with an increased risk for gestational diabetes mellitus in Egyptian women?

Abstract Background Genetic variants in the transcription factor 7-like 2 (TCF7L2) gene are related with type 2 diabetes (T2D) and gestational diabetes mellitus (GDM) in various populations, but there are not enough statistics regarding GDM among Egyptian women. We aimed by this study to evaluate the effect of two polymorphisms of rs7903146 and rs12255372 in the TCF7L2 gene with the development of GDM among Egyptian women. Results We enrolled 114 pregnant women with normal glucose tolerance and 114 with GDM according to the International Association of Diabetes and Pregnancy Study Groups (IADPSG) guidelines. We gathered records on blood pressure, body mass index (BMI), blood glucose level, hemoglobin A1C (HbA1c), and lipid profile. The genotyping of rs7903146 and rs12255372 polymorphisms was carried out using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP). The statistical significance of prepregnancy BMI, fasting blood sugar (FBS), HbA1c, low-density lipoprotein (LDL), and total cholesterol (Tch) was higher, P < 0.001, in GDM women in comparison to pregnant women without GDM. CT and TT genotypes in rs7903146 SNP were 46.5% vs. 54%, P <0.04, OR; CI = 1.9 (1.0 to 3.78); TT carriers were 37.7% vs. 9.6%, P <0.001, OR (CI) = 8.9 (3.7–21.1), respectively. For the TCFL2 gene rs12255372 SNP, GT carriers were 48.2% vs. 39.5%, P= 0.004, OR (CI) = 2.3 (1.3–4.2), while TT carriers were 24.6% vs. 7.9%, P < 0.001, OR (CI) = 6 (2.5–14.3). Conclusion The study showed there is a significantly higher incidence of CT/TT genotypes in rs7903146 SNP and GT/TT genotypes in rs12255372 SNP in TCF7L2 gene among GDM women in comparison to healthy pregnant women (controls)

Early diagnostic evaluation of miR-122 and miR-224 as biomarkers for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the common lethal types of tumor all over the world. The lethality of HCC accounts for many reasons. One of them, the lack of reliable diagnostic markers at the early stage, in this context, serum miRNAs became promising diagnostic biomarkers. Herein, we aimed to identify the predictive value of two miRNAs (miR-122 and miR-224) in plasma of patients with HCC preceded by chronic HCV infection. Taqman miRNA assays specific for hsa-miR-122 and hsa-miR-224 were used to assess the expression levels of the chosen miRNAs in plasma samples collected from three groups; 40 patients with HCC related to HCV, 40 with CHC patients and 20 healthy volunteers. This study revealed that the mean plasma values of miRNA-122 were significantly lower among HCC group when compared to CHC and control groups (P 1.2 (RQ) and (AUC = 0.93, P < 0.001), while the accuracy of AFP to diagnose HCC was (AUC: 0.619; P = 0.06). In conclusion, the expression plasma of miR-122 and miR-224 could be used as noninvasive biomarkers for the early prediction of developing HCC at the early stage

Epigenetic effects toward new insights as potential therapeutic target in B-thalassemia

Abstract Background Fetal hemoglobin (HbF) induction has shown promise for the treatment of β-hemoglobinopathies. HbF induction in β-thalassemia could overcome ineffective hematopoiesis and thus terminate transfusion dependency for formerly transfusion dependant patients. Several miRNAs have been found to reactivate γ-globin expression and increase HbF. In this study, we aimed to investigate the expression of 4 miRNAs (miR-15a, miR-16-1, miR-96, and miR-486-3p) in high HbF thalassemia patients and correlate their levels with the patients’ HbF levels then, in order to predict the exact role of the studied miRNAs in hematopoiesis, a bioinformatic analysis was carried out. We went through this bioinformatic analysis to determine the network of genes regulated by miRNAs and further investigate the interaction between all of them through their involvement in hematopoiesis. In this study, the differential expression was measured by qRT-PCR for 40 patients with high HbF and compared to 20 healthy controls. Bioinformatics was conducted involving functional annotation and pathway enrichment analyses. Results The studied microRNAs were significantly deregulated in thalassemia patients in correlation with HbF. Functional annotation and pathway enrichment analyses revealed a major role of miR-486-3p and miR-15a in HbF induction. Conclusion MiR-486-3p and miR-15a are crucial for HbF induction. Further validating studies are needed

Correlation of circulating miRNA-33a and miRNA-122 with lipid metabolism among Egyptian patients with metabolic syndrome

Abstract Background Metabolic syndrome is defined as a group of interrelated biochemical, clinical, and metabolic factors that directly increase the risk of cardiovascular disease, obesity, and type 2 diabetes mellitus. MicroRNA-33a (miR-33a) and MicroRNA-122 (miR-122) play a crucial role in various biological processes by regulating the gene expression level through post-transcriptional mechanisms, and alterations of their levels are associated with lipid and glucose metabolic disorders. In the present study, we aimed to investigate the correlation of miR-33a and miR-122 with obesity indices and glycemic parameters in a cohort of Egyptian patients. Quantitative real-time polymerase chain reaction (RT-PCR) using TaqMan assay was carried out to estimate the expression levels of miR-33a and miR-122 in serum samples of 100 patients diagnosed as having metabolic syndrome and 50 healthy controls. All patients (100%) had type 2 diabetes (by both history and laboratory assessment) and 70% were obese (BMI ≥ 30 kg/m2). Results Compared to controls, patients had significantly higher serum expression level of miR-33a (p value < 0.001) and miR-122 (p value = 0.0016). miR-33a was less expressed (downregulation expression) with 0.8 fold change in the patient group (obese and diabetic) compared to healthy controls, while miR-122 was highly expressed (upregulation expression) in the patient group of patients with 1.9 fold change. Clinical parameters as body mass index (BMI), wrist circumference (Wc), weight (Wt), and height (Ht) (all p < 0.001); total cholesterol (TC) (p = 0.0115); and triglyceride (TG) (p = 0.0286), all were significantly higher in patients compared to the healthy group. Both miRNAs show statistically significant correlations with clinical and biochemical parameters (p < 0.001). Conclusions Circulating miR-33a and miR-122 might be convincing as possible biomarkers for the diagnosis of metabolic syndrome

Genomic alterations in the F8 gene correlating with severe hemophilia A in Egyptian patients

Abstract Background Hemophilia A (HA) is an inherited X‐linked recessive coagulation disorder caused by factor VIII (F8) deficiency. F8 rearrangements involving intron 22 (int22) and intron 1 (int1) account for almost half of severe HA phenotype also a hotspot exon 14 provides numerous mutational patterns. This study aims to identify F8 gene mutations among Egyptian HA patients. Methods DNA samples from 60 HA patients were screened for int22 and int1 rearrangements using simplified inverse shifting PCR (IS‐PCR) followed by exon 14 sequencing. Also, four uncharacterized patients were studied by targeted exome sequencing. Results In 33.3% of the studied patients, we identified three int22 rearrangements, three exon 14 mutations (two frameshift; one novel (NM_000132.3:c.2734_2735delAA, p.(N912Ffs*6)), a second reported mutation (NM_000132.3:c.3091_3094delAGAA, p.(K1031Lfs*9)), and one nonsense mutation (NM_000132.3:c.2440C>T, p.(R814*)). All identified mutations were detected in patients with severe HA phenotype. Targeted exome sequencing could not detect any known pathogenic variants. Conclusion Intron 22 rearrangement and exon 14 mutations correlate with most severe hemophilia A Egyptian patients

Screening of Dystrophin Gene Deletions in Egyptian Patients with DMD/BMD Muscular Dystrophies

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are allelic disorders caused by mutations within the dystrophin gene. Our study has identified 100 Egyptian families collected from the Human Genetics Clinic, National Research Center, Cairo. All cases were subjected to complete clinical evaluation pedigree analysis, electromyography studies, estimation of serum creatine phosphokinase enzyme (CPK) levels and DNA analysis. Multiplex PCR using 18 pairs of specific primers were used for screening of deletion mutations within the dystrophin gene. A frequency of 55% among the families. Sixty per cent of detected deletions involved multiple exons spanning the major or the minor hot spot of the dystrophin gene. The remainder 40% which mainly involved exon 45. Comparing these findings with frequencies of other countries it was found that our figures fall within the reported range of 40%– for deletions. The distribution of deletions in our study and other different studies was variable and specific ethnic differences do not apparently account for specific deletions. In addition this study concluded that employment of the 18 exon analysis is a cost effective and a highly accurate (97% to launch a nationwide program