SNP:for my $snp (@SNPs) {
        my @get_SNPs = split(/\t/, $snp);
        my $position = $get_SNPs[3];

        last SNP if ($position > $end); # stop reading, we're out of range !
                                        
        if (($position >= $start) && ($position <= $end)) {
            print OUT "@get_SNPs";
        }
    }