A Rare t(9;22;16)(q34;q11;q24) Translocation in Chronic Myeloid Leukemia for Which Imatinib Mesylate Was Effective: A Case Report

The spectrum of chromosomal translocations in the Arab world: ethnic-specific chromosomal translocations and their relevance to diseases

Chromosomal translocations (CTs) are the most common type of structural chromosomal abnormalities in humans. CTs have been reported in several studies in the Arab world, but the frequency and spectrum of these translocations are not well characterized. The aim of this study is to conduct a systematic review to estimate the frequency and spectrum of CTs in the 22 Arab countries. Four literature databases were searched: PubMed, Science Direct, Scopus, and Web of Science, from the time of inception until July 2021. A combination of broad search terms was used to collect all possible CTs reported in the Arab world. In addition to the literature databases, all captured CTs were searched in three chromosomal rearrangement databases (Mitelman Database, CytoD 1.0 Database, and the Atlas of Genetics and Cytogenetics in Oncology and Hematology), along with PubMed and Google Scholar, to check whether the CTs are unique to the Arabs or shared between Arabs and non-Arabs. A total of 9,053 titles and abstracts were screened, of which 168 studies met our inclusion criteria, and 378 CTs were identified in 15 Arab countries, of which 57 CTs were unique to Arab patients. Approximately 89% of the identified CTs involved autosomal chromosomes. Three CTs, t(9;22), t(13;14), and t(14;18), showed the highest frequency, which were associated with hematological malignancies, recurrent pregnancy loss, and follicular lymphoma, respectively. Complex CTs were commonly reported among Arabs, with a total of 44 CTs, of which 12 were unique to Arabs. This is the first study to focus on the spectrum of CTs in the Arab world and compressively map the ethnic-specific CTs relevant to cancer. It seems that there is a distinctive genotype of Arabs with CTs, of which some manifested with unique clinical phenotypes. Although ethnic-specific CTs are highly relevant to disease mechanism, they are understudied and need to be thoroughly addressed.

A rare case of complex variant translocation of t(9;22;16)(q34;q11.2;q24) in a newly diagnosed patient with chronic myeloid leukemia

•

Complex Philadelphia chromosome translocations.

•

Variability of chromosomal translocations may impact treatment.

•

Genomic analysis is integral for molecular characterization of CML.

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm associated with the dysregulated production of myeloid cells. The Philadelphia chromosome (Ph), t(9;22)(q34;q11), is a hallmark of the disease and found in 90–95% of diagnosed CML patients. The balanced, reciprocal translocation places the genes BCR and ABL1, next to each other, resulting in an increase of kinase activity. Additional cases involve complex variants, including translocation events involving an additional chromosome with the creation of the Ph chromosome. A rare three-way Ph chromosome complex variant, t(9;22;16)(q34;q11.2;q24), was identified in a 40-year-old female who presented with visual changes and leukocytosis. Cytogenetic analysis by G-banding revealed the presence of a three-way translocation involving the long arms of chromosomes 9, 22, and 16. Fluorescence in situ hybridization with a dual-color fusion probe confirmed the presence of the BCR::ABL1 fusion.

Variant Philadelphia t(X;9;22)(q22?;q34;q11.2) can be successfully treated with second generation tyrosine kinase inhibitors: A case report and literature review

Chronic myeloid leukemia (CML) is characterized by the reciprocal translocation between chromosomes 9 and 22: t(9;22)(q34;q11). However, 5-10% of patients with CML have complex variant translocations involving at least a third chromosome; only a few cases affect the X chromosome. Therefore, the data available regarding their features and the response to treatment is limited. In the present report, a case of a variant Philadelphia translocation t(X;9;22)(q22?;q34;q11.2) identified in a 51-year-old female with a newly diagnosed CML is described. The patient was treated with nilotinib. A major molecular response was observed after 12 months of starting treatment. Deep molecular response was obtained 20 months later and maintained after the 110-month follow-up. Additionally, a literature review was performed, with the aim of comprehending the complex clinical and biological characteristics of CML cytogenetic variants involving the X chromosome.