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Last Updated: March 28, 2024

Claims for Patent: 5,552,283


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Summary for Patent: 5,552,283
Title: Method, reagents and kit for diagnosis and targeted screening for P53 mutations
Abstract:Rapid and cost effective diagnosis of p53 mutations of a sample of patients is achieved by employing a selected plurality of diagnostic tools, in a hierarchy of increasing accuracy and cost per tool, in which each tool detects essentially no false positives. Diagnostic tests that may be included among the plurality of tests selected include, in order of increasing accuracy and cost: (a) immunoassays, (b) analysis of DNA from a patient sample by quantitative amplification of p53 exons using amplification primers complementary to intron regions flanking each exon and examination of the length or quantity of each amplified fragment for nucleotide insertions or deletions relative to the normal p53 gene. Preferably, the amplification primers are multiplexed so that more than one DNA fragment is amplified in a single vessel, using sets of primers which provide gene fragments of distinctive lengths when used to amplify a normal p53 gene; and (c) analysis of DNA from a patient sample by DNA sequencing of the p53 gene beginning with the sequencing of those regions most likely to harbor point mutations, and proceeding to sequence regions less likely to harbor point mutations.
Inventor(s): Diamandis; Eleftherios (Toronto, CA), Dunn; James M. (Scarborough, CA), Stevens; John K. (Toronto, CA)
Assignee: Visible Genetics Inc. (Toronto, CA)
Application Number:08/388,381
Patent Claims:1. A method for testing a patient sample for a disease-associated mutation in the p53 gene, comprising the steps of:

(a) selecting a hierarchy of assay techniques comprising at least a first and final assay, said first assay being selected to provide a test for the presence or absence of the disease-associated mutation with essentially no false results indicating the presence of a mutation and said final assay being selected to provide a test for the presence or absence of the disease associated mutation with essentially no false results indicating the presence or absence of a mutation;

(b) analyzing the patient sample using the first assay; and, if the result of the first assay did not unambiguously indicate the presence of a disease-associated mutation,

(c) analyzing the patient sample using the final assay.

2. A method according to claim 1, wherein the first assay is an immunoassay.

3. A method according to claim 2, wherein the immunoassay detects the presence of anti-p53 antibodies.

4. A method according to claim 1, wherein the final assay determines the nucleic acid sequence of at least one exon of the p53 gene.

5. A method according to claim 4, wherein the exons are analyzed by sequence analysis in an order determined by the frequency of disease-associated point mutations within the exons, and wherein the sequences of exons having a lower frequency of point mutations are determined only if no mutation is detected by the sequencing of exons having a higher frequency of point mutations.

6. A method according to claim 4, wherein exon 1 of the p53 gene is sequenced.

7. A method according to claim 6, wherein the exon 1 is sequence using a sequencing primer selected from among the following primers:

8. A method according to claim 4, wherein exon 2 of the p53 gene is sequenced.

9. A method according to claim 8, wherein exon 2 is sequenced using a sequencing primer selected from among the following primers:

10. A method according to claim 4, wherein exon 3 of the p53 gene is sequence.

11. A method according to claim 10, wherein exon 3 is sequenced using a sequencing primer as follows:

12. A method according to claim 4, wherein exon 4 of pg53 gene is sequenced.

13. A method according to claim 12, wherein exon 4 is sequenced using a sequencing primer selected from among the following primers:

14. A method according to claim 4, wherein exon 5 of the p53 gene is sequenced.

15. A method according to claim 14, wherein exon 5 is sequenced using a sequencing primer selected from among the following primers:

16. A method according to claim 4, wherein exon 6 of the p53 gene is sequenced.

17. A method according to claim 16, wherein exon 6 is sequenced using a sequencing primer selected from among the following primers:

18. A method according to claim 4, wherein exon 7 of the p53 gene is sequenced.

19. A method according to claim 18, wherein exon 7 is sequenced using a sequencing primer selected from among the following primers:

20. A method according to claim 4, wherein exon 8 of the p53 gene is sequenced.

21. A method according to claim 20, wherein exon 8 is sequenced using a sequencing primer selected from among the following primers:

22. A method according to claim 4, wherein exon 9 of the p53 gene is sequenced.

23. A method according to claim 22, wherein exon 9 is sequenced using a sequencing primer selected from among the following primers:

24. A method according to claim 4, wherein exon 10 of the p53 gene is sequenced.

25. A method according to claim 24, wherein exon 10 is sequenced using a sequencing primer selected from among the following primers:

26. A method according to claim 4, wherein exon 11 of the p53 gene is sequenced.

27. A method according to claim 26, wherein exon 11 is sequenced using a sequencing primer selected from among the following primers:

28. A method according to claim 1, wherein the first assay comprises quantitative amplification of at least one p53 exon using amplification primers complementary to intron regions flanking each exon to produce amplified fragments, and examination of the length or quantity of each amplified fragment for nucleotide insertions or deletions relative to the normal p53 gene.

29. A method according to claim 28, wherein two or more exons are coamplified in a single amplification reaction mixture.

30. A method according to claim 29, wherein exons 1, 3, 4, 5, 6, 9 and 10 of the p53 gene are coamplified.

31. A method according to claim 30, wherein the exons are coamplified using primers of the sequence:

32. A method according to claim 29, wherein exons 2 and 8 of the p53 gene are coamplified.

33. A method according to claim 32, wherein the exons are coamplified using primers of the sequence:

34. A method according to claim 1, wherein the hierarchy of assay techniques selected further comprises an intermediate assay effective to detect at least some mutations which are not detected using the first assay, but which is not a test which provides essentially no false results indicating the absence of a mutation.

35. A method according to claim 34, wherein the intermediate assay comprises quantitative amplifications of p53 exons using amplification primers complementary to intron region flanking each exon to produce amplified fragments, and examination of the length or quantity of each amplified fragment for nucleotide insertion or deletions relative to the normal p53 gene.

36. A method according to claim 35, wherein two or more exons are coamplified in a single amplification reaction mixture.

37. A method according to claim 36, wherein exons 1, 3, 4, 5, 6, 9 and 10 of the p53 gene are coamplified.

38. A method according to claim 37, wherein the exons are coamplified using primers of the sequence:

39. A method according to claim 36, wherein exons 2 and 8 of the p53 gene are coamplified.

40. A method according to claim 39, wherein the exons are coamplified using primers of the sequence:

41. A method for testing a plurality of patients for a disease-associated mutation in the p53 gene comprising the steps of:

(a) performing an immunoassay on samples obtained from each of the plurality of patients, by combining a portion of sample with a specifically immunoreactive substance which forms an immunological reaction product by binding to p.hoarfrost.protein or anti-p53 antibodies and monitoring for formation of the immunological reaction product,

(b) separating the samples into a first set which tested positive in the immunoassay for formation of the immunological reaction product and a second set which tested negative in the immunoassay for formation of the immunological reaction product; and

(c) performing a DNA analysis which produces essentially no false results indicating the presence of a mutation in the p53 gene on samples from the second set, but not on samples from first set.

42. A method according to claim 41, wherein the DNA analysis performed comprises the steps of determining the sequence of DNA in at least one exon of the p53 gene on each patient sample in the second set, and comparing the sequence determined with the wild-type sequence of the p53 gene.

43. A method according to claim 41, wherein the DNA analysis performed comprises the steps of:

amplifying at least one exon of the p53 gene to produce amplification fragments and comparing the length and quantity of the amplification fragments to standard values for the amplified exon determined for wild-type p53;

separating the samples of the second set into a first subset and a second subset, wherein the first subset contains samples where the length or quantity of the amplification fragments differed from the standard value and the second subset contains samples where neither the length nor quantity differed from the standard value; and

determining the sequence of DNA in at least one exon of the p53 gene on each patient sample in the second subset, and comprising the sequence determined with the wild-type sequence of the p53 gene.

44. A method according to claim 43, wherein at least some of the exons are coamplified in a single amplification reaction mixture.

45. A method according to claim 44, wherein exons 1, 3, 4, 5, 6, 9 and 10 of the p53 gene are coamplified.

46. A method according to claim 44, wherein exons 2 and 8 of the p53 gene are coamplified.

47. A method for testing a plurality of patients for a disease-associated mutation in the p53 gene comprising the steps of:

(a) amplifying at least one exon of the p53 gene to produce amplification fragments and comparing the length and quantity of the amplification fragments to standard values for the amplified exon;

(b) separating the samples into a first set and a second set, wherein the first set contains samples where the length or quantity of the amplification fragments differed from the standard value and the second set contains samples where neither the length nor quantity differed from the standard value; and

determining the sequence of DNA in at least one exon of the p53 gene on each patient sample in the second set, and comparing the sequence determined with the wild-type sequence of the p53 gene.

48. A method according to claim 47, wherein at least some of the exons are coamplified in a single amplification reaction mixture.

49. A method according to claim 48, wherein exons 1, 3, 4, 5, 6, 9 and 10 of the p53 gene are coamplified.

50. A method according to claim 48, wherein exons 2 and 8 of the p53 gene are coamplified.

51. A method for generating a patient report on the presence or absence of p53 mutation comprising the steps of

(a) obtaining a sample of patient tissue;

(b) performing an immunoassay on the sample by combining a portion of sample with a specifically immunoreactive substance which forms an immunological reaction product by binding to p53 protein or anti-p53 antibodies and monitoring for formation of the immunological reaction product, wherein the presence or absence of an immunological reaction product is indicative of the presence of a mutation;

(c) performing a DNA analysis which produces essentially no false resulting indicating the presence of a mutation in the p53 gene on the sample if the no mutation was detected using the immunoassay; and

(d) generating a report indicating whether a mutation was found in the sample.

52. A method according to claim 51, wherein the DNA analysis performed comprises the steps of determining the sequence of DNA in at least one exon of the p53 gene and comparing the sequence determined with the wild-type sequence of the p53 gene.

53. A method according to claim 51, wherein the DNA analysis performed comprises the steps of:

amplifying at least one exon of the p53 gene to produce amplification fragments and comparing the length and quantity of the amplification fragments to standard values for the amplified exon, wherein a difference in the length or quantity of the amplification fragments is indicative of the presence of a mutation; and

if no mutation was detected based on the length and quantity of the amplification fragment, determining the sequence of DNA in at least one exon of the p53 gene and comparing the sequence determined with the wild-type sequence of the p53 gene.

54. A method according to claim 53, wherein at least some of the exons are coamplified in a single amplification reaction mixture.

55. A method according to claim 54, wherein exons 1, 3, 4, 5, 6, 9 and 10 of the p53 gene are coamplified.

56. A method according to claim 54, wherein exons 2 and 8 of the p53 gene are coamplified.

57. A method for generating a patient report on the presence or absence of p53 mutation comprising the steps of

(a) obtaining a sample of patient tissue;

(b) amplifying at least one exon of the p53 gene to produce amplification fragments and comparing the length and quantity of the amplification fragments to standard values for the amplified exon wherein a difference in the length or quantity of amplification fragments is indicative of a mutation;

(c) if no mutation was detected based on the length and quantity of amplification fragments, determining the sequence of DNA in at least one exon of the p53 gene on each patient sample in the second set, and comparing the sequence determined with the wild-type sequence of the p53 gene; and

(d) generating a report indicating whether a mutation was found in the sample.

58. A method according to claim 57, wherein at least some of the exons are coamplified in a single amplification reaction mixture.

59. A method according to claim 58, wherein exons 1, 3, 4, 5, 6, 9 and 10 of the p53 gene are coamplified.

60. A method according to claim 58, wherein exons 2 and 8 of the p53 gene are coamplified.

Details for Patent 5,552,283

Applicant Tradename Biologic Ingredient Dosage Form BLA Approval Date Patent No. Expiredate
Merck Sharp & Dohme Corp. INTRON A interferon alfa-2b For Injection 103132 06/04/1986 ⤷  Try a Trial 2014-07-08
Merck Sharp & Dohme Corp. INTRON A interferon alfa-2b For Injection 103132 ⤷  Try a Trial 2014-07-08
Merck Sharp & Dohme Corp. INTRON A interferon alfa-2b Injection 103132 ⤷  Try a Trial 2014-07-08
>Applicant >Tradename >Biologic Ingredient >Dosage Form >BLA >Approval Date >Patent No. >Expiredate

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