Most of you said IgM Nephropathy. That was what I was thinking as well. Why you might ask?
This is a tough question since some might even want to say LPHS as the answer since it might not be a real glomerular disease but the other three are!
There is some data that the Alport's, Thin Basement Membrane Disease and LPHS are all sort of related diseases leading to hematuria. When renal biopsy is performed, some patients have a known cause of hematuria such as IgA nephropathy or vasculitis. Such patients are considered to have secondary LPHS, while patients without signs of acquired underlying glomerular disease are considered to have primary LPHS. Renal biopsy in patients with primary LPHS shows evidence of glomerular hematuria, as manifested by red cells in the tubules. Most of the time, specimens show thin or thick glomerular basement membranes on electron microscopy, suggesting an important role for glomerular basement membrane abnormalities in the hematuria. All three of these diseases(LPHS, Alports and TBM) are related to the glomerular basement membrane.
IgM Nephropathy on the other hand is considered a minimal change variant. Usually this is a mesangial proliferative glomerulonephritis that has prominent diffuse mesangial deposits of IgM and complement, along with electron dense deposits in the mesangium. Alports, TBM and LPHS don't have deposits making it different from IgM as well. IgM does have glomerular basement membrane pathology but its due to deposits.
Groupers would group Alports, IgA Nephropathy, LPHS and TBM in one spectrum of disease; with Alports sort of being slightly different given its genetic nature.
Groupers would group Minimal Change, IgM nephropathy, C1q Nephropathy, mesangial proliferative disease and FSGS as one group as a spectrum.
While others can single each disease separately.
Eventhough I made this question up, its a bad question! but it sort of teaches us about grouping and thinking of what diagnosis to consider in certain situation and what not to consider in certain situations.