Claims for Patent: 6,063,567

Summary for Patent: 6,063,567

Title:	Method, reagents and kit for diagnosis and targeted screening for retinoblastoma
Abstract:	Reliable and cost effective testing for mutations in the RB1 gene can be accomplished by (a) quantitatively amplifying exons of the sample RB1 gene using primers complementary to intron regions flanking each exon; and (b) determining the lengths and/or quantities of the amplification products for each exon and comparing that length or quantity to the length or quantity of amplification products obtained when a wild-type RB1 gene is amplified using the same primers. Differences in length between an amplified sample exon and the corresponding amplified wild-type exon reflect the occurrence on an insertion or deletion mutation in the sample RB1 gene. Differences in quantity reflect the complete absence of an exon, or heterozygosity for a mutant exon. Next, the nucleic acid sequence of each exon found to contain an insertion or deletion mutation is determined, or of all exons in the event no insertion or deletion mutations are identified. Preferably, the amplification of the exons is multiplexed so that more than one exon is amplified in a single vessel using sets of primers which provide gene fragments of distinctive lengths when used to amplify a normal RB1 gene.
Inventor(s):	Gallie; Brenda L. (Toronto, CA), Dunn; James M. (Scarborough, CA), Stevens; John K. (Toronto, CA), Hui; May (Toronto, CA)
Assignee:	Visible Genetics Inc. (Toronto, CA)
Application Number:	08/779,916
Patent Claims:	1. A method for identifying mutations in a sample retinoblastoma gene comprising the steps of: (a) quantitatively coamplifying a plurality of exons of the sample retinoblastoma gene using primers complementary to intron regions immediately flanking each of the plurality of exons; (b) determining the lengths of the amplification products for each amplified sample exon and comparing that length to the length of amplification products obtained when a wild-type retinoblastoma gene is amplified using the same primers, whereby differences in length between an amplified sample exon and the corresponding amplified wild-type exon reflect the occurrence on an insertion or deletion mutation in the sample retinoblastoma gene; and (c) determining the nucleic acid sequence of each exon identified in step (b) to contain an insertion or deletion mutation, or in the event no insertion or deletion mutations are identified, determining the nucleic acid sequence of at least one exon of the retinoblastoma gene, sufficient exons being sequenced to identify the presence of a mutation if one exists in the sample retinoblastoma gene, wherein in step (a) exons 4, 5, 7, 8, 10, 11, 19 and 25 are coamplified in a single reaction. 2. A method for genetic screening of family members of an individual diagnosed as having retinoblastoma, comprising the steps of: (a) obtaining a patient blood sample from the diagnosed individual; (b) quantitatively amplifying at least one exon of the retinoblastoma gene in cells from the patient blood sample using primers complementary to intron regions immediately flanking each exon amplified; (c) determining the length of the amplification product for each exon amplified and comparing that length to the length of amplification products obtained when a wild-type retinoblastoma gene is amplified using the same primers, whereby differences in length between an amplified sample exon and the corresponding amplified wild-type exon reflect the occurrence of an inherited insertion or deletion mutation in the retinoblastoma gene of the diagnosed individual; and (d) if an inerited mutation is identified, obtaining blood samples from the biological parents of the diagnosed individual; quantitatively amplifying the exon of the retinoblastoma gene found to contain an insertion or deletion mutation in the patient blood sample in cells from the parent blood samples using the same primers used to amplify the exons in the patient blood sample; and determining the length of the amplification product for the exon in the amplified parent blood samples and comparing that length to the length of amplification products obtained when the patient blood sample was amplified, wherein in step (b) exons 4, 5, 7, 8, 10, 11, 19 and 25 are coamplified in a single reaction. 3. A method for generating a report on the nature of a mutation causing retinoblastoma in a patient, comprising the steps of (a) obtaining a sample of patient tissue containing a sample retinoblastoma gene, (b) quantitatively coamplifying a plurality of exons of the sample retinoblastoma gene using primers complementary to intron regions flanking each amplified exon; (c) determining the lengths of the amplification products for each amplified sample exon and comparing that length to the length of amplification products obtained when a wild-type retinoblastoma gene is amplified using the same primers, whereby differences in length between an amplified sample exon and the corresponding amplified wild-type exon reflect the occurrence on an insertion or deletion mutation in the sample retinoblastoma gene; (d) determining the nucleic acid sequence of each exon identified in step (c) to contain an insertion or deletion mutation, or in the event no insertion or deletion mutations are identified, the nucleic acid sequence of at least one exon of the sample retinoblastoma gene, sufficient exons being sequenced to identify the presence of a mutation if one exists in the sample retinoblastoma gene; and (e) generating a report identifying the exon in which the mutation, if any, is located, wherein in step (b) exons 4, 5, 7, 8, 10, 11, 19 and 25 are coamplified in a single reaction. 4. A method according to claim 1, further comprising coamplifying exons 12, 15, 16, 17, 18 and 21 in a single reaction mixture. 5. A method according to claim 1, further comprising coamplifying exons 3, 9, 13, 20, 23 and 24 in a single reaction mixture. 6. A method according to claim 1, further comprising coamplifying exons 2, 6, 14, 22, 26 and 27 in a single reaction mixture. 7. A method according to claim 2, wherein if at least one parent is found to carry the mutation found in the patient, further performing the steps of obtaining aunt/uncle blood samples from the siblings of the parent found to carry the mutation; quantitatively amplifying the exon of the RB 1 gene found to contain an insertion or deletion mutation in the patient blood sample in cells from the aunt/uncle blood samples using the same primers used to amplify the exons in the patient blood sample; and determining the length of the amplification product for the exon in the amplified aunt/uncle blood samples and comparing that length to the length of amplification products obtained when the patient blood sample was amplified. 8. A kit for identification of mutations in the retinoblastoma gene, comprising a plurality of primer pairs for multiplex coamplification of a selected plurality of exons of the retinoblastoma gene, wherein one member of each primer pair is labeled with a detectable label, and wherein the primer pairs are selected to have a common melting temperature and to produce amplification products having differing lengths and wherein the primers pairs bind to intron regions immediately flanking each of the selected plurality of exons, said kit comprising at least one set of primers for amplification of the selected plurality of exons of the retinoblastoma gene selected from among the following primer pairs: 9. A kit for identification of mutations in the retinoblastoma gene, comprising a plurality of primer pairs for multiplex coamplification of a selected plurality of exons of the retinoblastoma gene, wherein one member of each primer pair is labeled with a detectable label, and wherein the primer pairs are selected to have a common melting temperature and to produce amplification products having differing lengths and wherein the primers pairs bind to intron regions immediately flanking each of the selected plurality of exons, said kit comprising primers selected to permit coamplification of exons 2, 3, 5, 13 and 25 of the retinoblastoma gene. 10. A kit according to claim 9, comprising the following coamplification primers: 11. A kit for identification of mutations in the retinoblastoma gene, comprising a plurality of primer pairs for multiplex coamplification of a selected plurality of exons of the retinoblastoma gene, wherein one member of each primer pair is labeled with a detectable label, and wherein the primer pairs are selected to have a common melting temperature and to produce amplification products having differing lengths and wherein the primers pairs bind to intron regions immediately flanking each of the selected plurality of exons, said kit comprising primers selected to permit coamplification of exons 1, 8, 18, 21, 22, and 23 of the retinoblastoma gene. 12. A kit according to claim 11, comprising the following coamplification primers: 13. A kit for identification of mutations in the retinoblastoma gene, comprising a plurality of primer pairs for multiplex coamplification of a selected plurality of exons of the retinoblastoma gene, wherein one member of each primer pair is labeled with a detectable label, and wherein the primer pairs are selected to have a common melting temperature and to produce amplification products having differing lengths and wherein the primers pairs bind to intron regions immediately flanking each of the selected plurality of exons, said kit comprising primers selected to permit coamplification of exons 6, 7, 8, 9, 10, 11, 12, and 27 of the retinoblastoma gene. 14. A kit according to claim 13, comprising the following coamplification primers: 15. A kit for identification of mutations in the retinoblastoma gene, comprising a plurality of primer pairs for multiplex coamplification of a selected plurality of exons of the retinoblastoma gene, wherein one member of each primer pair is labeled with a detectable label, and wherein the primer pairs are selected to have a common melting temperature and to produce amplification products having differing lengths and wherein the primers pairs bind to intron regions immediately flanking each of the selected plurality of exons, said kit comprising primers selected to permit coamplification of exons 4, 14, 20, 24 and 26 of the retinoblastoma gene. 16. A kit according to claim 15, comprising the following coamplification primers: 17. A kit for identification of mutations in the retinoblastoma gene, comprising a plurality of primer pairs for multiplex coamplification of a selected plurality of exons of the retinoblastoma gene, wherein one member of each primer pair is labeled with a detectable label, and wherein the primer pairs are selected to have a common melting temperature and to produce amplification products having differing lengths and wherein the primers pairs bind to intron regions immediately flanking each of the selected plurality of exons, said kit comprising primers selected to permit coamplification of exons 15, 16, 17, and 19 of the retinoblastoma gene. 18. A kit according to claim 17, comprising the following coamplification primers: 19. A kit for identification of mutations in the retinoblastoma gene, comprising a plurality of primer pairs for multiplex coamplification of a selected plurality of exons of the retinoblastoma gene, wherein one member of each primer pair is labeled with a delectable label, and wherein the primer pairs are selected to have a common melting temperature and to produce amplification products having differing lengths and wherein the primers pairs bind to intron regions immediately flanking each of the selected plurality of exons, said kit comprising primers selected to permit coamplification of exons 4, 5, 7, 8, 10, 11, 19 and 25 in a single reaction mixture. 20. A kit for identification of mutations in the retinoblastoma gene, comprising a plurality of primer pairs for multiplex coamplification of a selected plurality of exons of the retinoblastoma gene, wherein one member of each primer pair is labeled with a detectable label, and wherein the primer pairs are selected to have a common melting temperature and to produce amplification products having differing lengths and wherein the primers pairs bind to intron regions immediately flanking each of the selected plurality of exons, said kit comprising primers selected to permit coamplification of exons 12, 15, 16, 17, 18 and 21 in a single reaction mixture. 21. A kit for identification of mutations in the retinoblastoma gene, comprising a plurality of primer pairs for multiplex coamplification of a selected plurality of exons of the retinoblastoma gene, wherein one member of each primer pair is labeled with a detectable label and wherein the primer pairs are selected to have a common melting temperature and to produce amplification products having differing lengths and wherein the primers pairs bind to intron regions immediately flanking each of the selected plurality of exons, said kit comprising primers selected to permit coamplification of exons 3, 9, 13, 20, 23 and 24 in a single reaction mixture. 22. A kit for identification of mutations in the retinoblastoma gene, comprising a plurality of primer pairs for multiplex coamplification of a selected plurality of exons of the retinoblastoma gene, wherein one member of each primer pair is labeled with a detectable label, and wherein the primer pairs are selected to have a common melting temperature and to produce amplification products having differing lengths and wherein the primers pairs bind to intron regions immediately flanking each of the selected plurality of exons, said kit comprising primers selected to permit coamlplification of exons 2, 6, 14, 22, 26 and 27 in a single reaction mixture. 23. A kit for identification of mutations in the retinoblastoma gene, comprising a plurality of primer pairs for multiplex coamplification of a selected plurality of exons of the retinoblastoma gene, wherein one member of each primer pair is labeled with a detectable label, and wherein the primer pairs are selected to have a common melting temperature and to produce amplification products having differing lengths and wherein the primers pairs bind to intron regions immediately flanking each of the selected plurality of exons, said kit further comprising a pair of sequencing primers effective to sequence at least one selected exon of the retinoblastoma gene, wherein the sequencing primers are selected from among the primers set forth in Table 2. 24. A method for identifying mutations in a sample retinoblastoma gene comprising the steps of: (a) quantitatively coamplifying a plurality of exons of the sample retinoblastoma gene using primers complementary to intron regions immediately flanking each of the plurality of exons to produce amplification products; (b) determining the lengths of the amplification products for each amplified sample exon and comparing that length to the length of amplification products obtained when a wild-type retinoblastoma gene is amplified using the same primers, whereby differences in length between an amplified sample exon and the corresponding amplified wild-type exon reflect the occurrence on an insertion or deletion mutation in the sample retinoblastoma gene; and (c) determining the nucleic acid sequence of each exon identified in step (b) to contain an insertion or deletion mutation, or in the event no insertion or deletion mutations are identified, determining the nucleic acid sequence of at least one exon of the retinoblastoma gene, sufficient exons being sequenced to identify the presence of a mutation if one exists in the sample retinoblastoma gene, wherein in step (b) exons 12, 15, 16, 17, 18 and 21 are coamplified in a single reaction. 25. A method for identifying mutations in a sample retinoblastoma gene comprising the steps of: (a) quantitatively coamplifying a plurality of exons of the sample retinoblastoma gene using primers complementary to intron regions immediately flanking each of the plurality of exons to produce amplification products; (b) determnining the lengths of the amplification products for each amplified sample exon and comparing that length to the length of amplification products obtained when a wild-type retinoblastoma gene is amplified using the same primers, whereby differences in length between an amplified sample exon and the corresponding amplified wild-type exon reflect the occurrence on an insertion or deletion mutation in the sample retinoblastoma gene; and (c) determining the nucleic acid sequence of each exon identified in step (b) to contain an insertion or deletion mutation, or in the event no insertion or deletion mutations are identified, determining the nucleic acid sequence of at least one exon of the retinoblastoma gene, sufficient exons being sequenced to identify the presence of a mutation if one exists in the sample retinoblastoma gene, wherein in step (a) exons 3, 9, 13, 20, 23 and 24 are coamplified in a single reaction. 26. A method for identifying mutations in a sample retinoblastotna gene comprising the steps of: (a) quantitatively coamplifying a plurality of exons of the sample retinoblastoma gene using primers complementary to intron regions immediately flanking each of the plurality of exons to produce amplification products; (b) determining the lengths of the amplification products for each amplified sample exon and comparing that length to the length of amplification products obtained when a wild-type retinoblastoma gene is amplified using the same primers, whereby differences in length between an amplified sample exon and the corresponding amplified wild-type exon reflect the occurrence on an insertion or deletion mutation in the sample retinoblastoma gene; and (c) determining the nucleic acid sequence of each exon identified in step (b) to contain an insertion or deletion mutation, or in the event no insertion or deletion mutations are identified, determining the nucleic acid sequence of at least one exon of the retinoblastoma gene, sufficient exons being sequenced to identify the presence of a mutation if one exists in the sample retinoblastoma gene, wherein in step (a) exons 2, 6, 14, 22, 26 and 27 are coamplified in a single reaction. 27. A reagent mixture comprising any of the primer pairs set forth in Table 1.

Details for Patent 6,063,567

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		2014-07-08
Merck Sharp & Dohme Corp.	INTRON A	interferon alfa-2b	For Injection	103132			2014-07-08
Merck Sharp & Dohme Corp.	INTRON A	interferon alfa-2b	Injection	103132			2014-07-08