Methods and systems for medical sequencing analysis

• US 8,140,270 B2
• Filed: 03/24/2008
• Issued: 03/20/2012
• Est. Priority Date: 03/22/2007
• Status: Active Grant

• Current Assignee: National Center For Genome Resources
• Original Assignee: National Center For Genome Resources
• Inventors: Kingsmore, Stephen F., Gessler, Damian D. G., May, Gregory D., Mudge, Joann
• Primary Examiner(s): Clow, Lori A
• Application Number:
  US12/054,072
• Publication Number:
  US 20090183268A1
• Time in Patent Office: 1,457 Days
• Field of Search: None
• US Class Current: 702/19
• CPC Class Codes: A61K 31/7088 Compounds having three or more nucleosides or nucleotides
• CPC Class Codes: C12Q 1/6883 for diseases caused by alterations of genetic material
• CPC Class Codes: C12Q 2600/106 Pharmacogenomics, i.e. genetic variability in individual responses to drugs and drug metabolism
• CPC Class Codes: C12Q 2600/136 Screening for pharmacological compounds
• CPC Class Codes: C12Q 2600/156 Polymorphic or mutational markers
• CPC Class Codes: C12Q 2600/158 Expression markers
• CPC Class Codes: C12Q 2600/172 Haplotypes

Abstract

Disclosed are methods of identifying elements associated with a trait, such as a disease. The methods can comprise, for example, identifying the association of a relevant element (such as a genetic variant) with a relevant component phenotype (such as a disease symptom) of the trait, wherein the association of the relevant element with the relevant component phenotype identifies the relevant element as an element associated with the trait, wherein the relevant component phenotype is a component phenotype having a threshold value of severity, age of onset, specificity to the trait or disease, or a combination, wherein the relevant element is an element having a threshold value of importance of the element to homeostasis relevant to the trait, intensity of the perturbation of the element, duration of the effect of the element, or a combination. The disclosed methods are based on a model of how elements affect complex diseases. The disclosed model is based on the existence of significant genetic and environmental heterogeneity in complex diseases. Thus, the specific combinations of genetic and environmental elements that cause disease vary widely among the affected individuals in a cohort. The disclosed model is an effective, general experimental design and analysis approach for the identification of causal variants in common, complex diseases by medical sequencing. The disclosed model and the disclosed methods based on the model can be used to generate valuable and useful information.

Claims

1. A computer-implemented method of identifying elements associated with a trait, the method comprising

selecting a set of discovery samples, wherein the set of discovery samples consist of samples from a single individual, samples from a single pedigree, samples from a subset of a single cohort, or samples from a single cohort;

identifying, by the computer, variant genetic elements in the discovery samples;

filtering, by the computer, the variant genetic elements to select candidate variant genetic elements, wherein the variant genetic elements are filtered by selecting variant genetic elements that are present in a threshold number of sequence reads, are present in a threshold percentage of sequence reads, are represented by a threshold read quality score at variant base(s), are present in sequence reads from in a threshold number of strands, are aligned at a threshold level to a reference sequence, are aligned at a threshold level to a second reference sequence, are variants that do not have biasing features bases within a threshold number of nucleotides of the variant or a combination;

prioritizing, by the computer, the candidate variant genetic elements to select relevant variant genetic elements; and

identifying, by the computer, an association of a relevant element with a relevant component phenotype of the trait, wherein the relevant element is selected from the relevant variant genetic elements and wherein the relevant element is an element having a threshold value of importance of the element to homeostatis relevant to the trait, intensity of the perturbation of the element, duration of the effect of the element, or a combination, wherein the relevant component phenotype is a component phenotype having a threshold value of severity, age of onset, specificity to the trait, or a combination, and wherein the association of the relevant element with the relevant component phenotype identifies the relevant element as an element associated with the trait.

2. The method of claim 1, wherein the association of the relevant element with the relevant component phenotype is identified by identifying the association of the relevant element with a network or pathway associated with the relevant component phenotype.

3. The method of claim 2, wherein the network or pathway is associated with the relevant component phenotype when the relevant component phenotype occurs or is affected when the network or pathway is altered.

4. The method of claim 1, wherein the association of the relevant element with the relevant component phenotype is identified by a threshold value of the coincidence of the relevant element and the relevant component phenotype within a set of discovery samples.

5. The method of claim 4, wherein the set of discovery samples consist of samples from a single individual, samples from a single pedigree, samples from a subset of a single cohort, samples from a single cohort, samples from multiple individuals, samples from multiple unrelated individuals, samples from multiple affected sib-pairs, samples from multiple pedigrees, or a combination.

6. The method of claim 5, wherein the set of discovery samples include both affected samples and unaffected samples, wherein affected samples are samples associated with the relevant component phenotype, wherein unaffected samples are samples not associated with the relevant component phenotype.

7. The method of claim 1, wherein the trait is a disease, a phenotype, a quantitative or qualitative trait, a disease outcome, or a disease susceptibility.

8. The method of claim 1, wherein the relevant element further is an element associated with one or more genetic elements associated with the trait.

9. The method of claim 8, wherein the one or more genetic elements are derived from DNA sequence data, genetic linkage data, gene expression data, antisense RNA data, microRNA data, proteomic data, metabolomic data or a combination.

10. The method of claim 1, wherein the relevant component phenotype further is a component phenotype associated with a network or pathway of interest.

11. The method of claim 10, wherein the relevant component phenotype is a component phenotype specific to the network or pathway of interest.

12. The method of claim 1, wherein the relevant element is a relevant genetic element.

13. The method of claim 1, wherein the threshold value of importance of the element to homeostatis relevant to the trait is derived from the phenotype of knock-out, transgenesis, silencing or overexpression of the element in an animal model or cell line;

the phenotype of a genetic lesion in the element in a human or model inherited disorder;

the phenotype of knock-out, transgenesis, silencing or overexpression of an element related to the element in an animal model or cell line;

the phenotype of a genetic lesion in an element related to the element in a human or model inherited disorder;

knowledge of the function of the element in a related species, or a combination.

14. The method of claim 13, wherein the element related to the element is a gene family member or an element with sequence similarity to the element.

15. The method of claim 1, wherein the threshold value of intensity of the perturbation of the element is derived from the type of element, the amount or level of the element, or a combination.

16. The method of claim 15, wherein the relevant element is a relevant genetic element, wherein the type of element is a type of genetic variant, wherein the type of genetic element is a regulatory variant, a non-regulatory variant, a non-synonymous variant, a synonymous variant, a frameshift variant, a variant with a severity score at, above, or below a threshold value, a genetic rearrangement, a copy number variant, a gene expression difference, an alternative splice isoform, or a combination.

17. The method of claim 15, wherein the relevant element is a relevant genetic element, wherein the amount or level of the element is the number of copies of the relevant genetic element, the magnitude of expression of the genetic element, or a combination.

18. The method of claim 1, wherein the element is an environmental condition, wherein the threshold value of duration of the effect of the element is derived from the duration of an environmental condition or the duration of exposure to an environmental condition.

19. The method of claim 1, wherein the element is a genetic element, wherein the threshold value of duration of the effect of the element is derived from the duration of expression of the genetic element, the expressivity of the genetic element, or a combination.

20. The method of claim 1, wherein the threshold value of severity of the component phenotype is derived from the frequency of the component phenotype, the intensity of the component phenotype, the amount of a feature of the component phenotype, or a combination.

21. The method of claim 1, wherein the threshold value of specificity to the trait of the component phenotype is derived from the frequency with which the component phenotype is present in other traits, the frequency with which the component phenotype is present in the trait, or a combination.

22. The method of claim 21, wherein the component phenotype is not present in other traits.

23. The method of claim 21, wherein the component phenotype is always present in the trait.

24. The method of claim 21, wherein the component phenotype is not present in other traits and is always present in the trait.

25. The method of claim 1 further comprising selecting an element as the relevant element by assessing the value of importance of the element to homeostatis relevant to the trait, intensity of the perturbation of the element, duration of the effect of the element, or a combination and comparing the value to the threshold value.

26. The method of claim 1 further comprising selecting a component phenotype as the relevant component phenotype by assessing the value of clinical features of the phenotype, and comparing the value to the threshold value.

27. The method of claim 26, wherein the clinical features of the phenotype comprise the value of severity, age of onset, duration, specificity to the phenotype, response to a treatment or a combination.

28. The method of claim 1 further comprising selecting a component phenotype as the relevant component phenotype by assessing the value of laboratory features of the phenotype, and comparing the value to the threshold value.

29. The method of claim 1, wherein the variant genetic elements are identified by sequencing nucleic acids from the discovery samples and comparing the sequences to one or more reference sequence databases.

30. The method of claim 29, wherein the comparison involves, but is not limited to, BLAST alignments, megaBLAST alignments, GMAP alignments, BLAT alignments or a combination.

31. The method of claim 29, wherein the reference sequence database is, but not limited to, the RefSeq genome database, the transcriptome database, the GENBANK database, or a combination.

32. The method of claim 1, wherein the variant genetic elements identified in the discovery samples are part of a catalog of variant genetic elements identified in a plurality of sets of discovery samples.

33. The method of claim 1, wherein the candidate variant genetic elements are prioritized according to the presence in the candidate variant genetic element of a non-synonymous variant in a coding region, the presence of the candidate variant genetic element in a plurality of samples, the presence of the candidate variant genetic element at a chromosomal location having a quantitative trait locus associated with the trait, the severity of the putative functional consequence that the candidate variant genetic element represents, the association of the candidate variant genetic element with a network or pathway in a plurality of samples, the association of the candidate variant genetic element with a network or pathway with which one or more other candidate variant genetic elements are associated, the plausibility or presence of a functional relationship between the candidate variant genetic element and the relevant component phenotype, or a combination.

34. The method of claim 1, wherein the association of a relevant element with a relevant component phenotype of the trait is performed for a plurality of relevant elements, a plurality of relevant component phenotypes of the trait, or a plurality of relevant elements and a plurality of relevant component phenotypes of the trait.

35. The method of claim 1, further comprising validating the association of the relevant element with the relevant component phenotype.

36. The method of claim 35, wherein association of the relevant element with the relevant component phenotype is validated by assessing the association of the relevant element with the relevant component phenotype in one or more sets of validation samples, wherein the set of validation samples is different than the samples from which the relevant element was selected.

37. The method of claim 36, wherein the set of validation samples consist of samples from a single individual, samples from a single pedigree, samples from a subset of a single cohort, samples from a single cohort, samples from multiple individuals, samples from multiple unrelated individuals, samples from multiple affected sib-pairs, samples from multiple pedigrees, or a combination.