OCDgender is a neurogender which can only be understood in the context of having OCD, it isn't OCD as a gender, but a gender that is effected and/or influenced by OCD by such a degree that they are linked.
One can call themselves just OCDgender, but it can also be combined with other genders, like OCDboy, OCDgirl, OCDnonbinary, etc.
Not eveyrone with OCD has OCDgender, but you have to have OCD to be OCD gender.