Marwa Zakaria

By Tamer Hassan, Mohamed Badr, Usama El Safy, Mervat Hesham, Laila Sherief and Marwa Zakaria

β-Thalassemias are extremely heterogeneous at the molecular level. More than 200 disease-causing mutations have been identified. The majority of mutations are single nucleotide substitutions. Rarely, β-thalassemia results from gross gene deletion. The degree of globin chain imbalance is determined by the nature of the mutation of the β-gene. β0 refers to the complete absence of production of β-globin on the affected allele. β+ refers to alleles with some residual production of β-globin (around 10%). In β++, the reduction in β-globin production is very mild. The broad spectrum of β-thalassemia alleles can produce a wide spectrum of different β-thalassemia phenotypes. In this chapter, we review the molecular basis of the marked heterogeneity of the thalassemia syndromes or in other words the genotype-phenotype relationship in β-thalassemia.

Part of the book: Epidemiology of Communicable and Non-Communicable Diseases

By Tamer Hassan, Mohamed Badr, Usama El Safy, Mervat Hesham, Laila Sherief, Mohamed Beshir, Manar Fathy, Mohamed Al Malky and Marwa Zakaria

Neuroblastoma is an embryonal malignancy that originates in the sympathetic nervous system. It is the most common solid tumor in infants and the most frequent extracranial solid tumor in children. Neuroblastoma accounts for 10% of childhood malignancies with 75% occurring in children <4 years. Stage, age, clinical and tumor genomic features are the principal criteria for determining treatment policy. Treatment modalities traditionally employed in the management of neuroblastoma are surgery, chemotherapy, and radiotherapy. Intensive multimodal treatment in patients with neuroblastoma has resulted in improved survival rates. However, there is a considerable percentage of patients with refractory and relapsed disease. Targeted therapy for neuroblastoma involves treatment aimed at molecular targets that have a unique expression in this childhood cancer. A large number of molecular targets have been identified for the treatment of high-risk and relapsed neuroblastoma. Treatment in this way aims at providing a more selective way to treat the disease and decreasing toxicities associated with the conventional treatment regimen.

Part of the book: Neuroblastoma

By Marwa Zakaria and Tamer Hassan

Part of the book: Contemporary Pediatric Hematology and Oncology

By Marwa Zakaria and Tamer Hassan

Part of the book: Beta Thalassemia

By Tamer Hassan and Marwa Zakaria

Beta-thalassemia is a genetic disease caused by mutations in the β-globin gene, resulting in partial or complete deficiency of β-chain. Deficiency of β-chain was accompanied by excess unmatched α-globin chains with subsequent dyserythropoiesis, oxidative stress, and chronic anemia. The main therapeutic option is blood transfusion that improves the anemic status but unfortunately exacerbates iron overload status. Till now, the only curative measure is allo-hematopoietic stem cell transplantation. New diagnostic and therapeutic modalities are now available. These include the preimplantation genetic diagnosis and new tools in the assessment of iron overload. Also, new therapeutic options aimed at different targets are being developed; for example, therapies that stimulate the synthesis of γ-globin and reduce the synthesis of α-globin, as well as the iron excess, dyserythropoiesis, and oxidative stress. However, the most likely ideal approach is efficient prevention, through genetic counseling, carrier detection, and prenatal diagnosis.

Part of the book: Beta Thalassemia