Membranous nephropathy in two human leukocyte antigen-identical brothers

We describe two Hispanic brothers with membranous nephropathy who had nephrotic syndrome in the first 2 years of life. Secondary causes of membranous nephropathy were excluded by clinical history and laboratory data. The occurrence of membranous nephropathy in these two young brothers, as well as in other familial cases reported to date, suggests an X-linked mode of inheritance.