Gene therapy is the process of introducing foreign genomic materials into host cells to elicit a therapeutic benefit. Although initially the main focus of gene therapy was on special genetic disorders, now diverse diseases with different patterns of inheritance and acquired diseases are targets of gene therapy. There are 2 major categories of gene therapy, including germline gene therapy and somatic gene therapy. Although germline gene therapy may have great potential, because it is currently ethically forbidden, it cannot be used; however, to date human gene therapy has been limited to somatic cells. Although numerous viral and nonviral gene delivery systems have been developed in the last 3 decades, no delivery system has been designed that can be applied in gene therapy of all kinds of cell types in vitro and in vivo with no limitation and side effects. In this review we explain about the history of gene therapy, all types of gene delivery systems for germline (nuclei, egg cells, embryonic stem cells, pronuclear, microinjection, sperm cells) and somatic cells by viral [retroviral, adenoviral, adeno association, helper-dependent adenoviral systems, hybrid adenoviral systems, herpes simplex, pox virus, lentivirus, Epstein–Barr virus)] and nonviral systems (physical: Naked DNA, DNA bombardant, electroporation, hydrodynamic, ultrasound, magnetofection) and (chemical: Cationic lipids, different cationic polymers, lipid polymers). In addition to the above-mentioned, advantages, disadvantages, and practical use of each system are discussed.

Developmental stuttering is a common disorder of speech dissiliency that is characterized by excessive repetitions of sounds, syllables, and monosyllabic words, as well as sound prolongations and complete blockages of the vocal tract. About 60 million people are affected and it is more common between the age of 3 and 6, when children begin forming sentences and connecting thoughts verbally. There are three types of stuttering known as developmental stuttering, neurogenic stuttering, and psychogenic stuttering. The exact pathophysiology of developmental stuttering is unknown; however, various family and twin studies have repeatedly implicated heredity as a major factor in the etiology of stuttering. It is clear that the genetic influence is not in the form of an exact single gene effect such as autosomal recessive, autosomal dominant, or x-linked in all families; however, in all of the inheritance forms it is influenced by sex with higher occurrence in males than females at a ratio of 4:1 in older children and adults. Recently special genetic locus has been determined on several autosomal chromosomes related to developmental stuttering. In this report, the proband is a 20-year-old boy was referred to our clinic for premarriage genetic counseling; he has been affected since 3 years and now is under cure. three generation study of his family show 13 individuals are affected by stuttering. For the first it occurred in the proband's grandfather and after this time about all of affected cases has been seen in consanguineous marriages. Therefore, the genetical inheritance of stuttering is crystal clear in this family and autosomal recessive inheritance pattern is proposed. Totally in such families with repeated occur of stuttering, we cannot account it as a multifactorial disorder.

Background:The second leading cause of cancer deaths in women is breast cancer. Germline mutations in susceptibility breast cancer gene BRCA1 increase the lifetime risk of breast cancer. Eighty-one large genomic rearrangements (LGRs) have been reported up to date in BRCA1 gene, and evaluation of these rearrangements helps with precise risk assessment in high-risk individuals. In this study, we have investigated LGRs in BRCA1 among Iranian high-risk breast cancer families.Materials and Methods:Seventy patients with breast cancer who were identified negative for point mutations or small deletions/insertions of BRCA1 gene were selected. Deletions and duplications of BRCA1 gene were evaluated using multiplex ligation-dependent probe amplification (MLPA).Results:Two deletions, deletion of exons 1A/1B-2 and exon 24, were detected in two patients with breast cancer. The former alteration was found in a woman with a strong family history of breast cancer while the latter one was detected in a woman with early onset of breast cancer.Conclusion:Although our data confirm that LGRs in BRCA1 comprise a relatively small proportion of mutations in hereditary breast cancer in the Iranian population, MLPA analysis might be considered for screening of LGRs in high-risk individuals. It is worth to note that our results are consistent with previous studies in various Asian and European countries.