Diagnosis and phenotypic assessment of Pakistani Haemophilia B carriers

Khan, Muhammad Tariq Masood; Naz, Arshi; Ahmed, Jawad; Shamsi, Tahir; Taj, Abid Sohail

doi:10.12669/pjms.333.12496

Cited by 4 publications

(4 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Prevention through prenatal diagnosis by Muhammad Arif Sadiq et al molecular diagnostic approaches includes linkage based analysis and direct variant analysis of disease causing variants. 11 The gold standard for molecular diagnosis of Haemophilia-A is direct identification of the gene variant. Direct variant analysis of defective gene also bears certain limitations which includes; complexity and large size of factor VIII gene, variant heterogeneity, labor intensive and high cost.…”

Section: Discussionmentioning

confidence: 99%

A basis for prenatal diagnosis of Haemophilia-A in Pakistani patients

Sadiq

Ahmed²,

Afzal³

et al. 2022

Pak J Med Sci

View full text Add to dashboard Cite

Objective: To screen Haemophilia-A patients for five known recurrent F8 gene variants and to analyze CA repeats in intron 13 of F8 gene in the mother and the affected child pairs. Methods: In this descriptive cross sectional study, 80 unrelated pairs of “mother and son” affected by Haemophilia-A were recruited as subjects. After collection of samples DNA was extracted using the Chelex (Bio-Rad, USA) method. Five known F8 gene variants were screened in the mothers and the affected sons by the allele specific PCR. The amplified products were separated on 2% agarose gels.CA repeats in intron 13 of the F8 gene in the mother and the affected child pairs were analyzed by Sanger sequencing method. The CA repeat alleles were used to look for the feasibility of linkage based diagnosis of Haemophilia-A in the affected families. The data were analyzed using Statistical Package for Social Sciences (SPSS) version 22.0. Results: In the 80 subject “mother and son” pairs a recurrent F8 gene variant was found in 32 pairs (40%). The most recurrent variant c.6869G>A was seen in 12 (15%). Linkage based analysis of the CA repeats in intron 13 was found to be informative in 29 (36.2%) mother-son pairs. Conclusion: The five known Haemophilia-A disease causing variants were found in 40% of the Pakistani Haemophilia-A patients. The five recurrent F8 gene variants and the CA repeats in intron 13 of F8 gene can provide a comprehensive basis for carrying out prenatal diagnosis and carrier screening in majority of the Pakistani Haemophilia-A families. doi: https://doi.org/10.12669/pjms.38.8.6524 How to cite this:Sadiq MA, Ahmed S, Afzal M, Tasfeen S. A basis for prenatal diagnosis of Haemophilia-A in Pakistani patients. Pak J Med Sci. 2022;38(8):---------. doi: https://doi.org/10.12669/pjms.38.8.6524 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

show abstract

Section: Discussionmentioning

confidence: 99%

A basis for prenatal diagnosis of Haemophilia-A in Pakistani patients

Sadiq

Ahmed²,

Afzal³

et al. 2022

Pak J Med Sci

View full text Add to dashboard Cite

show abstract

“…The developed strategy showed high informativeness (80%) and high usefulness for carrier diagnosis. Linkage analysis with intragenic neutral variants has shown wide variability depending on the population (30–80%) (Khan, Naz, Ahmed, Shamsi, & Taj, 2017; Mitchell, Mitchell, & Krause, 2007; Singh & Singh, 2008). In familial cases, we diagnosed carriers and noncarriers quickly and economically with confidence >95% by using intragenic neutral variants.…”

Section: Discussionmentioning

confidence: 99%

Genetic analysis for carrier diagnosis in hemophilia A and B in the Mexican population: 25 years of experience

González-Ramos¹,

Mantilla-Capacho²,

Luna-Záizar

et al. 2020

American J of Med Genetics Pt C

View full text Add to dashboard Cite

Our 25 years of experience in carrier diagnosis of hemophilia A (HA) and B (HB) in Mexican population comprises linkage analysis of intragenic F8/F9 neutral variants along with, in severe HA (SHA), detection of F8 int22h and int1h inversions. In symptomatic carriers (SCs) we explored Lyonization to explain their symtomatology. From a DNA-Bank of 3,000 samples, intragenic restriction fragment length (RFLPs) and short tandem repeats (STRs) of F8/F9 genes were assessed by PCR-PAGE and GeneScan. In SHA patients, F8 inversions were detected by inverse shifting-PCR/ diagnostic and complementary tests. In SCs, we evaluated hemorrhagic symptoms, clotting FVIII/FIX and X-chromosome inactivation (XCI) patterns were assessed by HUMARA assay and the search of XIST promoter pathogenic variants. Informativeness of linkage analysis for HA carrier diagnosis with RFLP's/STR's increased to 74% and reached 80% with five RFLPs for HB. Combined Inv22/Inv1 diagnosed 113 possible carriers, three de novo Inv22-1, and confirmed 45 mothers as obligate or sporadic carriers. Among 21 SCs, four showed extreme skewed XCI pattern (80:20) but had normal karyotype and no C43G pathogenic variant in XIST promoter. Clotting FVIII/ FIX correlated with the active X in leukocytes. Our data integrate the largest comprehensive research worldwide on the molecular diagnosis of HA and HB carriers in terms of the number of studied and diagnosed cases, in addition to the genetic analysis in SCs. Intragenic RFLPs and STRs of F8/F9 genes along with F8 int22h/int1h inversions in SHA emerge as optimal variants for molecular diagnosis in Mexican population. In counseling SCs, inheritance of skewed X-inactivation should be considered.

show abstract

“…Approximately 30% of the female individuals with heterozygous mutation have a coagulation factor activity less than 40% [22]. Increased bleeding tendency among the carriers, in comparison to normal females, is well documented [23,24]. In case of F9 sequence variants, besides classical HB, four other phenotypes are reported.…”

Section: Disease Penetrance and Expressivitymentioning

confidence: 99%

Genotype-Phenotype Heterogeneity in Haemophilia

Khan¹,

Taj²

2019

Hemophilia - Recent Advances

View full text Add to dashboard Cite

Haemophilia was previously regarded as a classical example of Mendelian inheritance, with mutation in only a single gene (F8 or F9) causing the disease phenotype. The disease manifests complete penetrance. Studies, however, revealed the striking genetic and phenotypic heterogeneities of the disease. With further sophistication of clinical and molecular techniques, the disease was also found to have allele heterogeneity, phenotypic plasticity and variation in expressivity. The variations are more pronounced in F9 variants with five distinct phenotypes. All these phenomena advocate a rather complex genotype-phenotype relationship for the disease. A keen insight into the matter may unveil new avenues of therapeutics.

show abstract

Diagnosis and phenotypic assessment of Pakistani Haemophilia B carriers

Cited by 4 publications

References 16 publications

A basis for prenatal diagnosis of Haemophilia-A in Pakistani patients

A basis for prenatal diagnosis of Haemophilia-A in Pakistani patients

Genetic analysis for carrier diagnosis in hemophilia A and B in the Mexican population: 25 years of experience

Genotype-Phenotype Heterogeneity in Haemophilia

Contact Info

Product

Resources

About