def tnuc_region_in_exon(np, beg, end):
    """ region in tnuc positions """
    if beg.tpos != 0:
        return False
    if end.tpos != 0:
        return False
    for i in range(beg.pos, end.pos - 1):
        if abs(np[i] - np[i + 1]) != 1:
            return False
    return True
