def check_if_not_dna(
        feature: str,
        dna: bool,
        not_dna) -> bool:
    """
    Checks whether a feature name do not contain
    any DNA character, as for a SEPP-based sequence
    placement need all features to be DNA sequences.

    Parameters
    ----------
    feature : str
        Feature name
    dna : bool
        Whether the previous feature name is not DNA
    not_dna
        Regex pattern to find the first non-DNA character

    Returns
    -------
    dna : bool
        Whether the current feature name is not DNA
    """
    if dna and bool(not_dna.search(feature)):
        dna = False
    return dna