Genotype-phenotype analyses of Iranian patients with hemophilia B (Leyden -) and hemophilia B (Leyden +): A single-center study.

BACKGROUND: There is a high prevalence of inherited bleeding disorders in Iran, such as hemophilia A (HA) and hemophilia B (HB). This study aimed to analyze the molecular and clinical profiles of patients with HB. METHODS: A single-center study was conducted among patients with severe HB between March 20, 2000, and June 31, 2023. The polymerase chain reaction (PCR) amplification was used for all of the major regions, such as the promoter, the exons, the adjacent intronic regions, and the untranslated regions of the F9 gene. Finally, Sanger sequencing was performed on the PCR products. RESULTS: A total of 111 HB patients (17 with HB [Leyden +] and 94 with HB [Leyden -]) were enrolled in this study. Among 94 patients with HB (Leyden -), 59 (62.8 %) had missense, 21 (22.3 %) had nonsense, and 8 (8.5 %) had frameshift mutations. Moreover, the most frequent pathogenic variant in HB (Leyden +) was c.-17 A>G in this study. CONCLUSION: The results of this study confirm that HB is caused by a wide range of molecular defects in Iran. Thus, by knowing the genotypes and phenotypes, we would be able to stratify the patients which is important in terms of their management and outcome.

Molecular and clinical profile of rare bleeding disorders: A single-center retrospective study.

INTRODUCTION: Due to their low frequency, there is little information on the molecular pathologies of rare bleeding disorders (RBD). Therefore, this study aimed to analyze the molecular and clinical profiles of patients with RBD. METHODS: A retrospective single-center study was conducted among patients with factor (F) II, FVII, FX, and FXIII deficiencies between March 20, 2000, and June 31, 2023. Data on patient demographics, genetic analysis, and laboratory results were documented for all patients. The disease severity was classified according to the clotting factor activity (except FXIII) as follows: >5%: mild, 1-5%: moderate, and <1%: severe. RESULTS: A total of 79 patients were enrolled in this study. Three of the cases had FII (3.7%), 40 had FVII (50.6%), 20 had FX (25.3%), and 16 had FXIII deficiency (20.2%). The median age of the patients at the time of diagnosis was six months for FII, 6.5 years for FVII, five months for FX, and 5.75 months for FXIII deficiencies, respectively. The major clinical manifestations were bruising, epistaxis, oral cavity bleeding, ecchymosis, and hemarthrosis. Consanguinity was present in 60 (76%) of patients. The majority of the patients had missense mutations. FVII mutations occurred primarily in exon 6, FX mutations affected mainly exons 2 and 7, and the majority of FXIII mutations occurred in exons 3 and 4. CONCLUSION: The diagnosis of the causative mutations in patients with RBD provides an insight into the underlying molecular basis of these disorders and probably explains their variable clinical manifestations.