Evaluation of intron 22 and intron 1 inversions of the factor 8 gene using an inverse shifting PCR method in severe haemophilia A patients

Abstract

Haemophilia A (HA) is an X-linked recessive bleeding disorder caused by several mutations in the F8 gene, whose inversion causes most of the mutation in 40% of severe HA patients. Methods such as long distance PCR and southern blot have been exploited to analyse intron 22 inversion in the F8 gene. For this purpose, we used an inverse shifting PCR assay, a novel genetic diagnostic method, for the detection of intron 22 inversion in severe HA patients. A screen for the presence of intron 22 and intron 1 inversions at the F8 gene in 30 Iranian severe HA patients revealed that 47% of patients showed intron 22 inversion (40% type 1 and 7% type 2), while 7% of patients had intron 1 inversion. Among the patients carrying the inversion, 12% developed inhibitors. Inverse shifting PCR is a precise method for assessment of rearrangements related to int 22h and int 1h in patients and carriers of haemophilia A. Since the previous methods of assessing inversion are time-consuming and demanding, this method can be a good replacement.

Mutation detection and inhibitor risk in Iranian patients with Hemophilia A: Six novel mutations

“…Rossetti et al observed the presence of inv22 in 45%‐50% of severe patients 9 . Moreover, in similar reports in Spain, Italy, Argentina, India, Egypt, Mexico, and Iran, inv22 is interpreted as the most frequent cause of severe HA 20‐22 . It should be noted that we reported the highest prevalence of inv22 mutation (40%), and this strongly supports previous studies.…”

“…9 Moreover, in similar reports in Spain, Italy, Argentina, India, Egypt, Mexico, and Iran, inv22 is interpreted as the most frequent cause of severe HA. [20][21][22] It should be noted that we reported the highest prevalence of inv22 mutation (40%), and this strongly supports previous studies. In most reports, the frequency of inv1 mutation has been stated to be 0%-5% of patients with severe HA.…”

Genotyping of Intron Inversions and Point Mutations in Exon 14 of the FVIII Gene in Iranian Azeri Turkish Families with Hemophilia A

“…Our findings confirm those of previous studies. The frequency of Inv 22 in our study was 44 %, which is similar to that in populations studied in the United Kingdom [13], Spain [17], Italy [18], Argentina [19,20], India [21], Egypt [22], Iran [23], Mexico [24], Hungary [15], and Costa Rica [25]. On the basis of these results, we concluded that the incidence in different populations is similar.…”

“…Our study showed that 1 (2 %) of 50 patients carried Inv 1. [6] in the United Kingdom, 0 % in Hungary [15], 0 % in Mexico [24], 0 % in Costa Rica [25], and 7 % in Iran [23].…”

Frequency of Intron 22 Inversion in Severe Hemophilia A Patients

“…This positive frequency is similar to previous studies from Egypt (46.1%), Iran (47%), and Iraq (36.3%) but lower than Jordan (52%) and Saudi Arabia (50%). It is higher than Albania (10.5%), Tunis (22.7%), Lebanon (29%), and the United Kingdom (17.6%) [13][14][15][16][17][18]. We detected inhibitors in 7.1% of Inv22 positive patients during our research.…”