minimal change nephrotic syndrome

  My first son was diagnosed with MCNS.  Is my second son at risk?  What are the causes?  My second son is a month old, what signs or symptoms should I be looking for?

[HFHS.MD-HSW]

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Dear Carrie:
I apologize for the long delay.
Minimal change nephrotic syndrome is one of the forms of primary nephrotic syndrome (i.e., not secondary to another disease such as hemolytic-uremic syndrome or systemic lupus erythematosus). For all subcategories of primary nephrotic syndrome combined, the risk of occurrence in a sibling is approximately one in thirty. The risk of your one-month-old son acquiring the nephrotic syndrome is less than that because the minimal change subcategory of primary nephrotic syndrome is least likely to affect siblings. The pattern of inheritance is unclear.
The origin of minimal change nephrotic syndrome remains unknown.
The peak period of occurrence of minimal change disease is between two and three years. 90% of the cases occur between the ages of one and five years.
Swelling (edema) of the tissues around the eyes is usually present in the morning upon arising when minimal change disease first manifests. This swelling is replaced by swelling of the feet and ankles as the child engages in upright activity.
I hope this is useful. It is provided for educational purposes only.
HFHS.MD-HSW
KEYWORDS: primary nephrotic syndrome, minimal change disease