Method and system for storing and accessing bioinformatics data
Method and system for storing and accessing genomic data. Genomic sequencing data are partitioned into access units of different types based on the predictability of the contained data. Access units are classified in different types and the structuring enables selective access and selective processing of genomic data.
1. A method of compression of genomic data mapped to a reference sequence comprising partitioning a file of genomic data into data unit of different types,
wherein said partitioning is such that
data units of a first type contain genomic data, said genomic data being a portion of a reference sequence used to map the encoded data, and positional data indicating the absolute position of the first nucleotide of said portion of the reference sequence, wherein said genomic data do not refer to data units of any other type,
data units of a second type comprise genomic data classified according to the mapping on the reference genome and structured in layers of homogeneous data, the data units of the second type also contain information related to positional data indicating the position of the reads perfectly matching the part of sequence contained in the data unit of a first type, and reverse complement information with respect to the genomic information contained in the data unit of a first type, and
wherein
said positional data in the data units of the second type are stored such that the mapping position of the first read is stored as absolute position and all the other positions are expressed as a difference with respect to the previous position and stored in a specific layer, and
said positional data and reverse complement data are structured in respective different layers of homogeneous data and are compressed by applying a specific compression algorithm.
2. The method of claim 1 , wherein said data units of a second type further comprise information related to genomic reads pairing and/or further information related to reads length.
3. The method of claim 1 , wherein the said partitioning the genomic data into data units of different types further comprises an additional type of data unit containing information related to positions of mismatches where the sequencing machine was not able to determine any nucleotide.
4. The method of claim 1 , wherein the said partitioning the genomic data into data units of different types further comprises an additional type of data unit containing information related to mismatch position and mismatch type, said mismatch relating to genomic data related to the data unit of the first type.
5. The method of claim 1 , wherein the said partitioning the genomic data into data units of different types further comprises an additional type of data unit containing information related to indels and mismatches position, indels and mismatches type and information on soft clipped nucleotides and info on hard clipped nucleotides.
6. The method of claim 1 , wherein the partitioning further comprises data units of another different type comprising information related metadata and/or quality scores and/or annotations data associated to the data units.
7. The method of claim 6 , wherein the partitioning further comprises data units of an additional different type that comprises annotations data.
8. The method of claim 7 , wherein the data of the data unit of claim 7 is organized into layers, each layer comprising information related to a different category: positional data, reverse complement, optionally paring, optionally mismatching and optionally annotations data.
9. The method of claim 1 , wherein the data units contain a header and payload data.
10. The method of claim 1 , wherein the data unit of second type comprises information about pairing of the reads and wherein the presence of such information is signaled in the header of the data unit.
11. The method of claim 1 , wherein the number of reads comprised in a data unit of a first type is set by an input configuration parameter.
12. The method of claim 11 , wherein said input configuration parameter is stored in the header of the data unit.
13. The method of claim 1 , wherein the content of the data units is encrypted.
14. Apparatus comprising means suitable for carrying out the method of claim 1 .
15. Storage device storing genomic data partitioned into data units according to the method of claim 1 .
16. A non-transitory computer readable recording medium having recorded thereon a program comprising instruction set for executing the method of claim 1 .
17. A method of compressing genomic data partitioned into data units according to the method of claim 1 , wherein said data are organized as to form a file format.
18. A method of transcoding a file of genomic data partitioned into data units created according to the method of claim 1 , such that when data are realigned versus a new reference genome only the payload information of the unit is modified, without having to transcode the entire file.
19. The method of claim 18 , wherein the file structure is left unaltered.
20. The method of claim 19 , wherein only selected data units are modified.
21. The method of claim 20 , wherein the selected data units are of said first type.
22. The method of claim 21 , wherein the selected data units are of any type.