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BACKGROUND Neurofibromatosis type 1 (NF1) is a neurocutaneous disorder that results in a predisposition to the growth of multiple tumors in the central nervous system, the peripheral nervous system, and the skin. The clinical manifestations of neurofibromatosis are associated with loss of neurofibromin expression which causes the upregulation of the RAS pathway. Although neurofibromatosis type 1 can be diagnosed based on the National Institutes of Health criteria, sometimes the diagnosis is difficult, in cases where the characteristic features do not develop. Moreover, other RAS-related disorders may present with significantly overlapping clinical features. AIMS To determine the clinical and molecular genetic characteristics of Turkish patients with neurofibromatosis type 1. STUDY DESIGN Cross-sectional study. METHODS For the genetic analysis of 27 Turkish families clinically diagnosed with NF1 between 1990 and 2019, we used a multi-step process consisting of next-generation sequencing, multiplex ligation-dependent probe amplification, and array-comparative genomic hybridization. RESULTS In this study, we identified 11 novel and 11 previously reported single-nucleotide variants in 22 families. Whole gene deletions were detected by multiplex ligation-dependent probe amplification analysis in 3 families. Of those, array comparative genomic hybridization analysis defined a 17q11.2 deletion in 4 patients from 2 families and 1.2-Mb involving 1 unrelated patient. All patients with a deletion had facial dysmorphism, suggesting a peculiar phenotype in this group. We could not find any pathogenic variant in the 2 families that met the National Institutes of Health criteria. CONCLUSION The novel pathogenic variants identified in this study broaden the spectrum of pathogenic variants in NF1 and provide better clinical characterization of NF1. RNA-seq experiments are recommended in patients who meet the National Institutes of Health diagnostic criteria for NF but have not identified any variants in nextgeneration sequencing, multiplex ligation-dependent probe amplification, or array-comparative genomic hybridization analysis.

Chronic myelogenous leukemia (CML) is the outcome of a chromosomal translocation and abl and bcr genes fusion. The present study is an attempt to implement a simple and inexpensive method for quantification of bcr-abl fusion transcripts in CML patients. Competitive RT-PCR technique was used to quantify bcr-abl transcripts. Internal control DNA piece was designed and synthesized from a non-human source, which was smaller than the target DNA in length but with the end identical to the main target piece. Following proliferation and purification, the transcriptions were quantified. To optimize reaction condition, competitive PCR was first performed separately on the target DNA with a given number of copies and a given number of copies of internal controls and the result of the reaction was electrophoresed for all concentrations of agarose electrophoreses gel. Results of simultaneous reactions of target RNA along with different number of copies of internal controls showed that the number of target RNA copies can e determined through comparing intensity of the color of DNA bands on the gel. The results showed that comparing with other methods like Real-time, the competitive RT-PCR is a relatively efficient and economic method to quantify bcr-abl transcripts.