def _is_possible_loh(rec, vcf_rec, params, somatic_info, use_status=False, max_normal_depth=None):
    """Check if the VCF record is a het in the normal with sufficient support.

    Only returns SNPs, since indels tend to have less precise frequency measurements.
    """
    if _is_biallelic_snp(rec) and _passes_plus_germline(rec, use_status=use_status):
        stats = _tumor_normal_stats(rec, somatic_info, vcf_rec)
        depths = [tz.get_in([x, "depth"], stats) for x in ["normal", "tumor"]]
        depths = [d for d in depths if d is not None]
        normal_freq = tz.get_in(["normal", "freq"], stats)
        tumor_freq = tz.get_in(["tumor", "freq"], stats)
        if all([d > params["min_depth"] for d in depths]):
            if max_normal_depth and tz.get_in(["normal", "depth"], stats, 0) > max_normal_depth:
                return None
            if normal_freq is not None:
                if normal_freq >= params["min_freq"] and normal_freq <= params["max_freq"]:
                    return stats
            elif (tumor_freq >= params["tumor_only"]["min_freq"] and
                    tumor_freq <= params["tumor_only"]["max_freq"]):
                if (vcf_rec and not _has_population_germline(vcf_rec)) or is_population_germline(rec):
                    return stats
Check if the VCF record is a het in the normal with sufficient support.

    Only returns SNPs, since indels tend to have less precise frequency measurements.