how can i refactor multiple only if condition

Here i want to check all properties of object one by one and check if it's not NAN than apply some logic else skip for each properties.

for that i have to make multiple ifs. is there better way i should do it?

internal class cls_pro
{
    public double A;
    public double B;
    public double C;
    public double D;
    public double E;
    public double F;
}

class Program
{
    static void Main(string[] args)
    {
        cls_pro obj = new cls_pro();
        obj.A = 1;
        obj.B = 3;
        obj.C = 1;
        obj.D = 23;
        obj.E = double.NaN;
        obj.F = double.NaN;


        // If propertie is not null some logic will apply
        if (!double.IsNaN(obj.A)) { ;}
        if (!double.IsNaN(obj.B)) { ;}
        if (!double.IsNaN(obj.C)) { ;}
        if (!double.IsNaN(obj.D)) { ;}
        if (!double.IsNaN(obj.E)) { ;}
        if (!double.IsNaN(obj.F)) { ;}

        Console.ReadLine();
    }
}