Genetic of Hereditary angioedema - Research Paper Example

Mutation can result from alteration or modification in the nucleotide sequence. In line with this, Type-III individuals involve mutation in F12 gene which codes for coagulation factor XII (Hageman factor). Since Type-III is estrogen dependent, this type of HAE occurs only among the female population. Up to date, only Faiyaz-Ul-Haque et al. (2010) conducted a study with regard to HAE among the Middle Eastern Arab patients. HAE is a rare kind of hereditary disorder (Kesim et al., 2011). Therefore, healthcare professionals should study the genetic etiology of this disease by determining its genetic components that have occurred in different geographical region across the world.

To assist the healthcare professionals in their study of HAE in UAE, a literature review will be conducted to identify the genetic etiology of HAE. Literature Review HAE can result from the functional deficiency of the C1 esterase inhibitor (C1INH) protein (Gosswein et al., 2008; Papadopoulou-Alataki et al., 2008). Basically, C1INH is an inhibitor that activates the proteases C1r and C1s. C1INH is also responsible for activating the coagulation Factor XII (responsible for checking the formation of bradykinin) and the plasma kallikrein (Duan et al.

2009; Bell et al., 2008; Gosswein et al., 2008). Pappalardo et al. (2008) explained that deficiency of C1INH is actually caused by the mutations in its structural gene. Using a genetic screening method for C1INH gene (SERPIN1G) in Italy, Pappalardo et al. (2008) found out that the presence of amino acid residues, which are important in protein function, could trigger mutations in the C1INH gene. Also related to the functional deficiency of C1INH, Papadopoulou-Alataki et al. (2008) revealed that “a new missense mutation in exon 2 of the C1INH gene, c.1A>G; p.Met-22Val (p.Met1Val)”, is common among patients with HAE.

A study carried out in Greece by Speletas et al. (2009), with 11 HAE cases from 3 unrelated families, displayed diminished C1 inhibitor antigen levels when analysis was performed for SERPING1 mutations. The findings recognized conversion of TC to AA as the main cause of alteration. This toggle can turn the codon as a stop signal to terminate the polypeptide. However, the second family exhibited W482X mutation, while the third family displayed missense mutation M1V, signifying diversity in mutation in the area.

Genetic mutation analysis in similar manner was performed in a Turkish family by Bork et al (2011), suggesting that HAE individuals with normal C1-inhibitor possess two missense mutations in codon of coagulation factor 12 gene in a few families, while in others, deletion of 72 base pairs (bp) was recognized. The study instituted deletion of 48 base pairs of exon 9, (otherwise responsible for coding amino acids 324 to 340), together with 24bp deletion of intron 9. Deletion of 72 bp was situated in the same F12 gene region as the missense mutations p.

Thr328Lys* and p.Thr328Arg* accounted earlier, signifying a close linkage between F12 gene mutations altering the FXII proline. The mutation in the region was associated with proline rich sequence of FXII protein and HAE cases with normal C1-ING (Bork et al., 2011). Duan et al. (2009) also performed genetic analysis of FXII and bradykinin catabolic enzymes in Type-III