dbNSFP.pm

=head1 LICENSE

Copyright [1999-2015] Wellcome Trust Sanger Institute and the EMBL-European Bioinformatics Institute
Copyright [2016-2018] EMBL-European Bioinformatics Institute

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

=head1 CONTACT

 Ensembl <http://www.ensembl.org/info/about/contact/index.html>
    
=cut

=head1 NAME

 dbNSFP

=head1 SYNOPSIS

 mv dbNSFP.pm ~/.vep/Plugins
 ./vep -i variations.vcf --plugin dbNSFP,/path/to/dbNSFP.gz,col1,col2

=head1 DESCRIPTION

 A VEP plugin that retrieves data for missense variants from a tabix-indexed
 dbNSFP file.
 
 Please cite the dbNSFP publication alongside the VEP if you use this resource:
 http://www.ncbi.nlm.nih.gov/pubmed/21520341
 
 You must have the Bio::DB::HTS module or the tabix utility must be installed
 in your path to use this plugin. The dbNSFP data file can be downloaded from
 https://sites.google.com/site/jpopgen/dbNSFP.

 Note that the 3.x releases of dbNSFP use GRCh38/hg38 coordinates; to use
 this plugin with GRCh37/hg19 data, please download instead one of the 2.9.x
 releases of dbNSFP.
 
 The file must be processed and indexed by tabix before use by this plugin:
 
 > wget ftp://dbnsfp:dbnsfp@dbnsfp.softgenetics.com/dbNSFPv3.2a.zip
 > unzip dbNSFPv3.2a.zip
 > head -n1 dbNSFP3.2a_variant.chr1 > h
 > cat dbNSFP3.2a_variant.chr* | grep -v ^#chr | sort -k1,1 -k2,2n - | cat h - | bgzip -c > dbNSFP.gz
 > tabix -s 1 -b 2 -e 2 dbNSFP.gz

 UPDATE: Release 3.5c of dbNSFP uses GRCh38/hg38 coordinates and GRCh37/hg19
 coordinates. If you want to use GRCh38 follow the previous instructions.
 For GRCh37 and release 3.5c the file must be processed differently:

 > wget ftp://dbnsfp:dbnsfp@dbnsfp.softgenetics.com/dbNSFPv3.5c.zip
 > unzip dbNSFPv3.5c.zip
 > head -n1 dbNSFP3.5c_variant.chr1 > h
 > cat dbNSFP3.5c_variant.chr* | grep -v ^#chr | awk '$8 != "."' | sort -k8,8 -k9,9n - | cat h - | bgzip -c > dbNSFP_hg19.gz
 > tabix -s 8 -b 9 -e 9 dbNSFP_hg19.gz
 
 When running the plugin you must list at least one column to retrieve from the
 dbNSFP file, specified as parameters to the plugin e.g.
 
 --plugin dbNSFP,/path/to/dbNSFP.gz,LRT_score,GERP++_RS
 
 Tabix also allows the data file to be hosted on a remote server. This plugin is
 fully compatible with such a setup - simply use the URL of the remote file:
 
 --plugin dbNSFP,http://my.files.com/dbNSFP.gz,col1,col2

 The plugin replaces occurrences of ';' with ',' and '|' with '&'. However, some
 data field columns, e.g. Interpro_domain, use the replacement characters. We
 added a file with replacement logic for customising the required replacement
 of ';' and '|' in dbNSFP data columns. In addition to the default replacements
 (; to , and | to &) users can add customised replacements. Users can either modify
 the file dbNSFP_replacement_logic in the VEP_plugins directory or provide their own
 file as second argument when calling the plugin:

 --plugin dbNSFP,/path/to/dbNSFP.gz,/path/to/dbNSFP_replacement_logic,LRT_score,GERP++_RS
 
 Note that transcript sequences referred to in dbNSFP may be out of sync with
 those in the latest release of Ensembl; this may lead to discrepancies with
 scores retrieved from other sources.

 If the dbNSFP README file is found in the same directory as the data file,
 column descriptions will be read from this and incorporated into the VEP output
 file header.
 
=cut

package dbNSFP;

use strict;
use warnings;

use Bio::EnsEMBL::Utils::Sequence qw(reverse_comp);

use Bio::EnsEMBL::Variation::Utils::BaseVepTabixPlugin;

use base qw(Bio::EnsEMBL::Variation::Utils::BaseVepTabixPlugin);

my %INCLUDE_SO = map {$_ => 1} qw(missense_variant stop_lost stop_gained start_lost);

sub new {
  my $class = shift;
  
  my $self = $class->SUPER::new(@_);

  $self->expand_left(0);
  $self->expand_right(0);
  
  # get dbNSFP file
  my $file = $self->params->[0];
  $self->add_file($file);
  
  # get headers
  open HEAD, "tabix -fh $file 1:1-1 2>&1 | ";
  while(<HEAD>) {
    next unless /^\#/;
    chomp;
    $self->{headers} = [split];
  }
  close HEAD;
  
  die "ERROR: Could not read headers from $file\n" unless defined($self->{headers}) && scalar @{$self->{headers}};
  
  # check alt and Ensembl_transcriptid headers
  foreach my $h(qw(alt Ensembl_transcriptid)) {
    die "ERROR: Could not find required column $h in $file\n" unless grep {$_ eq $h} @{$self->{headers}};
  }

  my $i = 1; 
  # check if 2nd argument is a file that specifies replacement logic
  # read replacement logic 
  my $replacement_file = $self->params->[$i];
  if (defined $replacement_file && -e $replacement_file) {
    $self->add_replacement_logic($replacement_file);  
    $i++;
  } else {
    $self->add_replacement_logic();  
  } 
 
  # get required columns
  while(defined($self->params->[$i])) {
    my $col = $self->params->[$i];
    die "ERROR: Column $col not found in header for file $file. Available columns are:\n".join(",", @{$self->{headers}})."\n" unless grep {$_ eq $col} @{$self->{headers}};
    
    $self->{cols}->{$self->params->[$i]} = 1;
    $i++;
  }
  
  die "ERROR: No columns selected to fetch. Available columns are:\n".join(",", @{$self->{headers}})."\n" unless defined($self->{cols}) && scalar keys %{$self->{cols}};
  
  return $self;
}

sub feature_types {
  return ['Transcript'];
}

sub get_header_info {
  my $self = shift;

  if(!exists($self->{_header_info})) {

    # look for readme
    my $file_dir = $self->files->[0];

    my %rm_descs;

    # won't work for remote
    if($file_dir !~ /tp\:\/\//) {

      # get just dir
      $file_dir =~ s/\/[^\/]+$/\//;

      if(opendir DIR, $file_dir) {
        my ($readme_file) = grep {/dbnsfp.*readme\.txt/i} readdir DIR;
        closedir DIR;

        if(open RM, $file_dir.$readme_file) {
          my ($col, $reading);

          # parse dbNSFP readme
          # relevant lines look like:
          #
          # 1   column1_name: description blah blah
          #     blah blah blah
          # 2   column2_name: description blah blah
          #     blah blah blah

          while(<RM>) {
            chomp;
            s/\r$//g;

            if(/^\d+\s/) {
              $reading = 1;

              m/^\d+\s+(.+?)\:\s+(.+)/;
              $col = $1;

              $rm_descs{$col} = '(from dbNSFP) '.$2 if $col && $2;
            }
            elsif($reading && /\w/) {
              s/^\s+//;
              $rm_descs{$col} .= ' '.$_;
            }
            else {
              $reading = 0;
            }
          }

          close RM;

          # remove multiple spaces
          $rm_descs{$_} =~ s/\s+/ /g for keys %rm_descs;
        }
      }
    }

    $self->{_header_info} = {map {$_ => $rm_descs{$_} || ($_.' from dbNSFP file '.$self->{file})} keys %{$self->{cols}}};
  }
  
  return $self->{_header_info};
}

sub run {
  my ($self, $tva) = @_;
  
  # only for missense variants
  return {} unless grep {$INCLUDE_SO{$_->SO_term}} @{$tva->get_all_OverlapConsequences};
  
  my $vf = $tva->variation_feature;
  
  return {} unless $vf->{start} eq $vf->{end};
  
  # get allele, reverse comp if needed
  my $allele = $tva->variation_feature_seq;
  reverse_comp(\$allele) if $vf->{strand} < 0;
  
  return {} unless $allele =~ /^[ACGT]$/;
  
  # get transcript stable ID
  my $tr_id = $tva->transcript->stable_id;

  my $data;
  my $pos;

  my $assembly = $self->{config}->{assembly};
 
  foreach my $tmp_data(@{$self->get_data($vf->{chr}, $vf->{start} - 1, $vf->{end})}) {
    # compare allele and transcript
    if ($assembly eq 'GRCh37') {
      if (exists $tmp_data->{'pos(1-coor)'}) {
        # for dbNSFP version 2.9.1
        $pos = $tmp_data->{'pos(1-coor)'}
      } elsif (exists $tmp_data->{'hg19_pos(1-based)'}) {
        # for dbNSFP version 3.5c indexed for hg19/(=GRCh37)
        $pos =  $tmp_data->{'hg19_pos(1-based)'}
      } else {
        die "dbNSFP file does not contain required columns (pos(1-coor) for version 2.9.1 or hg19_pos(1-based) for version 3.5c) to use with GRCh37";
      }
    } else {
      if (exists $tmp_data->{'pos(1-based)'}) {
        $pos = $tmp_data->{'pos(1-based)'}
      } else {
        die "dbNSFP file does not contain required column pos(1-based) to use with GRCh38";
      }
    }

    next unless
      $pos == $vf->{start} &&
      defined($tmp_data->{alt}) &&
      $tmp_data->{alt} eq $allele;
    
    # make a clean copy as we're going to edit it
    %$data = %$tmp_data;

    # convert data with multiple transcript values
    # if($data->{Ensembl_transcriptid} =~ m/\;/) {

    #   # find the "index" of this transcript
    #   my @tr_ids = split(';', $data->{Ensembl_transcriptid});
    #   my $tr_index;

    #   for my $i(0..$#tr_ids) {
    #     $tr_index = $i;
    #     last if $tr_ids[$tr_index] =~ /^$tr_id(\.\d+)?$/;
    #   }

    #   next unless defined($tr_index);

    #   # now alter other fields
    #   foreach my $key(keys %$data) {
    #     if($data->{$key} =~ m/\;/) {
    #       my @split = split(';', $data->{$key});
    #       die("ERROR: Transcript index out of range") if $tr_index > $#split;
    #       $data->{$key} = $split[$tr_index];
    #     } 
    #   }
    # }
    last;
  }
  
  return {} unless scalar keys %$data;
  
  # get required data
  my @from = @{$self->{replacement}->{default}->{from}};
  my @to = @{$self->{replacement}->{default}->{to}};

  my %return;
  foreach my $colname (keys %$data) {
    next if(!defined($self->{cols}->{$colname}));
    next if($data->{$colname} eq '.');

    my @from = @{$self->{replacement}->{default}->{from}};
    my @to   = @{$self->{replacement}->{default}->{to}};
    @from    = @{$self->{replacement}->{$colname}->{from}} if (defined $self->{replacement}->{$colname});
    @to      = @{$self->{replacement}->{$colname}->{to}} if (defined $self->{replacement}->{$colname});
    for my $i (0 .. $#from) {
      $data->{$colname} =~ s/\Q$from[$i]\E/$to[$i]/g;
    }
    $return{$colname} = $data->{$colname};
  }
  
  return \%return;
}

sub parse_data {
  my ($self, $line) = @_;

  $line =~ s/\r$//g;

  my @split = split /\t/, $line;
  
  # parse data into hash of col names and values
  my %data = map {$self->{headers}->[$_] => $split[$_]} (0..(scalar @{$self->{headers}} - 1));

  return \%data;
}

sub get_start {  
  return $_[1]->{'pos(1-based)'};
}

sub get_end {
  return $_[1]->{'pos(1-based)'};
}

sub add_replacement_logic {
  my $self = shift;
  my $file = shift;
  $file ||= 'dbNSFP_replacement_logic';
  if (! -e $file) {
    $self->{replacement}->{default}->{from} = [';', '|'];
    $self->{replacement}->{default}->{to} = [',', '&'];
  } else {
    open FILE, $file;
    while(<FILE>) {
      chomp;
      next if /^colname/;
      my ($colname, $from, $to) = split/\s+/;
      die ("ERROR: 3 values separated by whitespace are required: colname from to.") if(!($colname && $from && $to));
      push @{$self->{replacement}->{$colname}->{from}}, $from;
      push @{$self->{replacement}->{$colname}->{to}}, $to;
    }
    close FILE;
    die("ERROR: No default replacement logic has been specified.\n") if (!defined $self->{replacement}->{default});
  }
}

1;