use strict;
use warnings;

$\ = "\n";
$, = '';

my %H;
my %D;

<>; # toss the header

while (<>) {
    chomp;
    my ($snpname, $snpidx, $acgt, $chomosomelist, $locus, $location) = split;

    unless (defined $location) {
        print STDERR $ARGV, '(', $., '): malformed entry - ', $_;
        next;
    }

#> adjust these as required to get a proper "label" and "value"

    $snpname .= '-' . $snpidx;
    $locus   .= '(' . $location . ')';

    foreach my $c (split /;/, $chomosomelist) {
        $H{$c}++;
        $D{$snpname}->{$c} = $locus;
    }
}

sub csv {
    local $, = ',';
    print map { defined $_ ? '"' . $_ . '"' : '"NA"' } @_;
}

my @H = sort keys %H;

csv '', @H;

foreach my $snpname (sort keys %D) {
    my $X = $D{$snpname};
    csv $snpname, map { $X->{$_} } @H;
}