-
[show abstract]
[hide abstract]
ABSTRACT: To establish a simple, rapid and easy method for screening the gene mutation in hemophilia A, which was further applied to a direct diagnosis and carrier detection at gene level.
Twenty-four clinically diagnosed hemophilia pedigrees, including all the hemophilia patients and female members, were tested for the introns 22 and 1 in factor VIII gene by using inversion polymerase chain reaction (PCR) and regular PCR techniques. All the 26 exons of factor VIII gene were consecutively screened in the 17 patients manifesting non-inverted sequences in intron 22 by using PCR, subsequently all the 37 amplicons resulted from 26 exons were analyzed by conformation sensitive gel electrophoresis (CSGE), finally the mutated exons were subjected to sequencing verification. According to the mutation results, mothers and twin sisters of the hemophilia probands were tested by CSGE or subjected to nucleotide sequencing directly, to ascertain if those individuals had the same mutation or were the carriers of disease-causing gene.
Intron 22 inversion was detected in 7 hemophilia probands out of 24 hemophilia pedigrees, intron 1 inversion was not detected in these pedigrees. Single-base mutations distributed in different exons of factor VIII gene were detected in 13 pedigrees with family history and 3 sporadic pedigrees, diagnosed as non-inverted 22 intron patients. By comprehensive usage of PCR-CSGE and nucleotide sequencing, the positive rate and the diagnosable rate of gene diagnosis or carrier detection in the 24 hemophilia pedigrees was 94.12% and 100% respectively.
PCR-CSGE is a highly sensitive and special assay for detecting single base mutation. By integrated utilization of introns 22 and 1 of factor VIII gene detection and PCR-CSGE genotyping, combining with nucleotide sequencing, a direct diagnosis of all hemophilia pedigrees be could nearly make at gene level, including the sporadic families. This method might be used to screen new mutation theoretically and ascertain the mutation type. It is a simple, rapid and low-cost method, possessing unique advantages in direct diagnosis of hemophilia A and carrier screening. It should have important application value in hemophilia diagnosis.
Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics 08/2009; 26(4):393-9.
-
Paula D James,
Colleen Notley,
Carol Hegadorn, Jayne Leggo,
Angie Tuttle,
Shawn Tinlin,
Christine Brown,
Chandler Andrews,
Andrea Labelle,
Yvette Chirinian,
Lee O'Brien,
Maha Othman,
Georges Rivard,
Dilys Rapson,
Christine Hough,
David Lillicrap
[show abstract]
[hide abstract]
ABSTRACT: In order to evaluate the changes within the VWF gene that might contribute to the pathogenesis of type 1 von Willebrand disease (VWD), a large multicenter Canadian study was undertaken. We present data from the sequence analysis of the VWF gene in 123 type 1 VWD index cases and their families. We have identified putative mutations within the VWF gene in 63% (n = 78) of index cases, leaving 37% (n = 45) with no identified changes. These changes comprise 50 different putative mutations: 31 (62%) missense mutations, 8 (16%) changes involving the VWF transcriptional regulatory region, 5 (10%) small deletions/insertions, 5 (10%) splicing consensus sequence mutations, and 1 nonsense mutation. Twenty-one of the index cases had more than one putative VWF mutation identified. We were somewhat more likely to identify putative mutations in cases with lower VWF levels, and the contribution of other factors, such as ABO blood group, seems more important in milder cases. Taken as a whole, our data support a complex spectrum of molecular pathology resulting in type 1 VWD. In more severe cases, genetic changes are common within the VWF gene and are highly penetrant. In milder cases, the genetic determinants are more complex and involve factors outside of the VWF gene.
Blood 02/2007; 109(1):145-54. · 9.90 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Aminoglycoside antibiotics exhibit their bactericidal effect by interfering with normal ribosomal activity. In this pilot study, we have evaluated the effect of the aminoglycoside antibiotic gentamicin on the factor VIII (FVIII) and IX levels of severe hemophiliacs with known nonsense mutations. Five patients were enrolled and each patient was given 3 consecutive days of gentamicin at a dose of 7 mg/kg intravenously every 24 hours. Two patients (patient no. 1: hemophilia A, Ser1395Stop; and patient no. 5: hemophilia B, Arg333Stop) showed a decrease in their activated partial thromboplastin time (aPTT), an increase in their FVIII (0.016 IU/mL, 1.6%) or FIX (0.02 IU/mL, 2%) levels, and an increase in thrombin generation. The remaining 3 patients (patient no. 2: hemophilia B, Arg252Stop; patient no. 3: hemophilia A, Arg2116Stop; and patient no. 4: hemophilia A, Arg427Stop) showed no response in the aPTTs or factor levels, but one (patient no. 2: hemophilia B, Arg252Stop) showed an increase in the factor IX antigen level (2%-5.5%) that persisted throughout the period of the study and was concordant with an increase in thrombin generation. Gentamicin is unlikely to be an effective treatment for severe hemophilia due to its potential toxicities and the minimal response documented in this report. This study, however, does provide a proof of principle, suggesting that ribosomal interference with a less toxic agent may be a potential therapeutic mechanism for severe hemophilia patients with nonsense mutations.
Blood 12/2005; 106(9):3043-8. · 9.90 Impact Factor
