use strict;
use warnings;

my %GeneCount = ();

#open the textfile GeneType.txt
open (GENETYPE, "GeneType.txt") or die "Could not open file: '$!'";

my $header = <GENETYPE>;  # read the header before entering the loop

while (<GENETYPE>) {
    chomp;
    my ($GeneName, $GeneType)= split (/\t/, $_);
    $GeneCount{$GeneType}++;
}

for my $type (sort keys %GeneCount) {
    print "$type: $GeneCount{$type}\n";
}