Using package genealogytree, how do I make invisible a particular line connecting two nodes?

Using the genealogytree package, I am combining trees that span several generations. One of the trees has no-one in the first generation, so I’ve used a g[phantom] to keep the positioning correct. This makes Gen1 (in the MWE below) invisible, but the connecting line between the invisible Gen 1 and the visible Gen2 is also visible.
How can I remove / make invisible the line above Gen2M?

MWE:

documentclass{minimal}
usepackage[all]{genealogytree}
usepackage{xcolor}
usepackage{tikz}
usetikzlibrary{trees}

begin{document}
begin{tikzpicture}
gtrset{processing=tcbox*}

genealogytree
{
child
    {
    g[phantom*]{Gen1}
        child
        {
        g[male]         {Gen2M}
        p[female]       {Gen2F}
        }
    }   
}

end{tikzpicture}
end{document}