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Aim: Chronic lymphocytic leukemia (CLL) is a highly heterogenous hemopathy. Genetic stratification of CLL patients has important prognostic and therapeutic values – mainly immunoglobulin heavy chain variable region gene (IGHV) mutational status and the presence of cytogenetic abnormalities. The genetics of CLL in Lebanon is scarcely described in the literature. Patients & methods: In this work, we studied the genetic biomarkers of 312 Lebanese CLL patients. Results: Prominent IGHV genes were IGHV4-34, IGHV1-69 and IGHV3-30; and CLL #1 and #5 presented major subsets. Some similarities as well as major differences were highlighted when comparing our data with previously published data. Conclusion: The distribution of IGHV alleles in our series differed from previously described distributions, suggesting involvement of antigenic selection and regional variables in CLL pathogenesis. [ABSTRACT FROM AUTHOR]

Cystic fibrosis is the most common life‐limiting autosomal recessive disease in western countries with an incidence of 1:2500 in United States and 1:1000 in some European countries. Similar incidences were noted for the Middle East with variations from 1 in 2560 to 1 in 15,876 according to the degree of consanguinity. This is a preliminary systematic study that aims to assess the incidence and carrier rate of cystic fibrosis in the Middle Eastern Lebanese population; known for a high frequency of consanguinity. One hundred thirteen DNA samples were collected from neonatal blood cards obtained from newborns to healthy unrelated families with no previous history of Cystic fibrosis. Screening for Cystic Fibrosis‐causing pathogenic variants was performed using next generation sequencing, and 17 different single nucleotide variants were detected, including six pathogenic and likely pathogenic. 5.5%–7% newborns were found to be carriers of a variant strongly suggestive of pathogenicity and comparable to published literature worldwide. This pilot analysis highlights the challenging interpretation of CFTR variants in a country underrepresented by large ethnic population analyses, and stresses the importance of premarital screening programs for Cystic fibrosis. [ABSTRACT FROM AUTHOR]

β-Thalassemia (β-thal) is highly prevalent among the Mediterranean populations. In Lebanon, the carrier rate of the disease is estimated to be around 2.0–3.0%. In this retrospective study, we determined the spectrum of β-thal mutations in a total of 170 individuals from a sample of 140 Lebanese, Iraqi and Syrian refugee families in Lebanon, over a period from 2012 to 2018. Twenty-eight different β-globin gene mutations were identified. The most prevalent mutations were IVS-I-110 (G>A) (HBB: c.93-21G>A), IVS-II-1 (G>A) (HBB: c.315+1G>A), IVS-I-6 (T>C) (HBB: c.92+6T>C) and IVS-I-1 (G>A) (HBB: c.92+1G>A), accounting for the majority of mutations found in HBB mutations analysed in 250 alleles. Ten different β-globin gene mutations that were not previously described in Lebanon were identified in our study. These mutations include the IVS-II-848 (C>A) (HBB: c.316–3C>A), codons 9/10 (+T) (HBB: c.30_31insT), codon 15 (–T) (HBB: c.46delT), −86 (C>G) (HBB: c.-136C>G), Cap +22 (G>A) (HBB: c.-29G>A), −28 (A>C) (HBB: c.−78A>C), codon 7 (GAG>TAG) (HBB: c.22G>T), codon 26 (GAG>TAG) (HBB: c.79G>T), codons 41/42 (–TTCT) (HBB: c.126_129delCTTT), and codons 82/83 (–G) (HBB: c.250delG). Of these, six mutations [codons 9/10, codon 15 (–T), −86, codon 7, codon 26, codons 82/83) were identified in Lebanese samples only; one mutation (IVS-II-848) was identified in both Lebanese and Iraqis; and three mutations (Cap +22, −28, codons 41/42) were identified in Iraqi samples only. Further studies will help better delineate the spectrum of β-thal mutations among different ethnic groups, and provide crucial prevention strategies. [ABSTRACT FROM AUTHOR]

Abstract: Background: Cystic fibrosis (CF) is the most common autosomal recessive disease in Caucasians; it is however, considered to be rare in the Arab populations. Reports of the cystic fibrosis transmembrane regulator (CFTR) mutations from Arabs, especially from the Lebanese population, are limited. Methods: Twenty-two unrelated Lebanese families, with at least one child with CF, were studied. DNA extracts from blood samples of patients and parents were screened for CFTR gene mutations. Results: Eleven different mutations were identified. Of the 44 alleles studied, the most common mutations were: F508del (34%), N1303K (27%), W1282X (7%), and S4X (7%). Five mutations – not previously reported in the Lebanese population – were identified; these are: S549N, G542X, 2043delG, 4016insG, and R117H-7T. Conclusions: The most common CFTR mutations in addition to five mutations not previously described in the Lebanese population were identified. Identification of CFTR mutations in the Lebanese population is important for molecular investigations and genetic counseling. [ABSTRACT FROM AUTHOR]