From Genome Analysis Wiki
Jump to: navigation, search


4,987 bytes added, 23:29, 19 July 2019
no edit summary
= Introduction =
'''Minimac4 ''' is a latest version in the series of genotype imputation software - preceded by [[Minimac3|Minimac3]] (2015), [[Minimac2|Minimac2]] (2014), [[Minimac|minimac]] (2012) and [[MaCH|MaCH]] (2010). '''Minimac4''' is a lower memory and more computationally efficient implementation of the original algorithms with negligible fall in comparable imputation quality.
The Minimac3 mailing list has been renamed as the Minimac4 mailing list. If you were already a member, no need to re-join. If not, please join our [| mailing list] to get updates about future releases or report possible bugs or email them to [ Ketian Yu] or [ Sayantan Das].'''
= Download Installation =
'''Minimac4 (version 1.0.0, released 2.14.2018)''' is currently available for testing purposes only (while we still run more tests and wait on feedback about potential bugs)[https://github. Commonly used reference panels in <font face=Courier>M3VCF<com/font> format are available for download in [[#Reference Panels for Download | Reference Panels]Santy-8128/Minimac4 Minimac4 Github].
'''VERSIONThe easiest way to install Minimac4 and its dependencies is to use the file provided. git clone <nowiki>https: 1.0//github.2 !!! (Updated 6com/statgen/Minimac4.29git</nowiki> cd Minimac4 bash install.2017) !!!'''sh
'''Github Repo:''' : Please see [ Minimac4 Github] for the full instructions for installation. Commonly used reference panels in <font face=Courier>M3VCF</font> format are available for download in [[#Reference Panels for Download | Reference Panels]].
= What's New =
The input file format, output file formats and typical command lines are the same in Minimac4 (as they were in minimac3). Some of the main new features are summarized below:
* '''Improved Speed - ''' Minimac4 is approximately '''6 times''' faster for 1000 Genomes Phase 1 and Phase 3 and '''2 times''' faster for the HRC reference panels at comparable accuracy (details of accuracy for imputing into 10 European samples are given here). The speed can be further improved by tuning the approximation parameters (see below), but we recommend using the default values.
* '''Automated Chunking - ''' Minimac4 automatically chunks the whole chromosome (into overlapping chunks), analyzes each chunk sequentially and then concatenates the imputed chunks back. This caps the memory usage across different chromosomes (memory requirement is based on chunk size, not chromosome size). The length of the chunk and the overlap can be controlled by the <code>--chunkLengthMb</code> and <code>--chunkLengthOverlapMb</code> options, although we recommend using the default values of 20 and 3, respectively.
* '''Approximations - ''' Minimac4 uses some simple approximations to speed up the imputation analyses. The levels of approximation can be controlled by the parameters <code>--probThreshold</code>, <code>--diffThreshold</code>, and <code>--topThreshold</code> (details given in Minimac4 Usage). Higher levels of approximation will reduce the compute time but marginally reduce the imputation accuracy. We recommend using the default values (0.01).
* '''Improved Chromosome X/Y Support - ''' Minimac4 can handle different ploidys in the same VCF file for imputation of sex chromosomes. For example, for the non-PAR region on chromosome X, males and females can be imputed together, irrespective of whether males are coded as haploids or diploids. However, each sample must have a fixed ploidy. Thus, PAR and non-PAR regions still need to be imputed separately. Please see Chromosome X Imputation for more details.
* '''Other Helpful Features'''
** We introduced a new feature called <code>--memUsage</code> that will estimate and report the memory required by Minimac4. This feature should be useful for users running their jobs on a compute cluster that requires memory specification.
** We introduced some other FORMAT options for the output dosage data, allowing users to retrieve haplotype dosages, genotype probabilities, genotype dosages or any other measure of summary that they want.
** We have fixed the bug related to FILTER=GENOTYPED and FILTER=GENOTYPED_ONLY which was causing a crash in bcftools.
* '''Obsolete Features'''
** In Minimac4, we removed the <code>--doseOutput</code> and <code>--hapOutput</code> options. Please use [[DosageConvertor]] to convert your files to MaCH or PLINK dosage format.
** Currently Minimac4 can ONLY handle M3VCF format files. If your reference panel is in VCF format, please use [[Minimac3]] to convert the VCF file to M3VCF (along with parameter estimation) and then use that M3VCF for imputation using Minimac4. The same holds for the option <code>--processReference</code> as well. Although the handle is made available, we will implement it in a later version.
** Parameters such as <code>--rounds</code>, <code>--states</code>, <code>--rec</code>, <code>--err</code> have been deactivated for now until we implement parameter estimation in minimac4.
= Usage =
A typical Minimac4 command line for imputation is as follows
minimac4 --refHaps refPanel.m3vcf \
--haps targetStudy.vcf \
--prefix testRun
Here <font face=Courier>refPanel.m3vcf</font> is the reference panel used in M3VCF format (e.g. 1000 Genomes), <font face=Courier>targetStudy.vcf</font> is the phased GWAS data in VCF format, and <font face=Courier>testRun</font> is the prefix for the output files.
=== Full List of Options ===
Please see '''[[Minimac4 Documentation]]''' for detailed explanation of all available options.
Also, users can always type the following for the full list of available options:
minimac4 --help
=== Convert VCF to M3VCF ===
If the reference panel is in VCF format, please use [[Minimac3]] to convert it into M3VCF format first.
../bin/Minimac3 --refHaps refPanel.vcf \
--processReference \
--prefix refPanel
=== Multi-Threading ===
The following example shows the same analysis as above, but using 5 threads:
minimac4 --refHaps refPanel.m3vcf \
--haps targetStudy.vcf \
--prefix testRun \
--cpus 5
= Reference Panels for Download =
| [ Download] <!--[ Download]-->
= Useful Wiki Pages =
There are a few pages in this Wiki that may be useful to for '''Minimac4''' users. Here are links to a few:
* [[Minimac4| Minimac4 Overview Page]]
* [[Minimac4 Documentation]]
* [[M3VCF Files| M3VCF Files]]

Navigation menu