I had read and been told that Leber's Congenital Amaurosis (LCA) can sometimes include certain complications with the kidneys. I was told repeatedly by parents that I should have my son's "kidneys checked out."
So, being a responsible parent, I took my son to his pediatrician and told her I'd like to have his "kidneys checked out." She nodded in approval and was completely on board, but then asked me a question I wasn't prepared for: "So, what do you want us to test for?"
I thought I was acting as an informed parent, but I really had no idea. I only had a vague notion of what the kidneys do when operating correctly, I had no idea what we should test for in order to check if they were malfunctioning.
So I took to the internet, did some research, and asked around and this is what I found. LCA is sometimes associated with Senior Loken Syndrome (SLS) or Alport Syndrome (AS), both of which affect the kidneys. There seems to be a genetic link between LCA and these two disorders. I looked into SLS and AS and determined how the kidneys are effected by these diseases. Then I made a list of tests and symptoms for our doctor.
Below are possible tests to check kidney function in LCA patients. We took this list to our doctor and decided as a team which tests made the most sense for our son.
This list is in no way professional nor will it catch everything. I only post it here because I think other parents and patients might find it useful. Please do not consider this medical advice and do consult with your own doctor.
- Look for cysts (SLS is associated with polycystic kidney disease and medullary cystic renal disease)
- Look for thickening of kidney filtration tissue (AS)
Blood
- Increased blood creatinine level (SLS)
- Increased blood urea nitrogen (SLS)
- Low blood sodium levels (SLS, called hyponatremia caused by renal salt wasting)
- Low bicarbonate levels (<24 mmol/l) (SLS, metabolic acidosis)
- Increased eosinophils (eosinophil granulocytes) (SLS, tubulointerstitial nephropathy)
- Low red blood cell count (SLS, anemia)
- Check blood phosphate level (AS)
- Check blood calcium level (AS)
Urine
- Protein (kidney failure often accompanied by abnormal appearance of protein in the urine, called proteinuria)
- Increased eosinophils (eosinophil granulocytes) (SLS, tubulointerstitial nephropathy)
- Inability to concentrate urine (SLS)
- Unusual urine color (AS)
- Blood in urine (AS, hematuria)
Other signs
- Excessive liquid intake (polydipsia)
- Production of large volume of urine (polyuria)
- Urinary incontinence/inability to hold urine (enuresis)
This list is in no way professional nor will it catch everything. I only post it here because I think other parents and patients might find it useful. Please do not consider this medical advice and do consult with your own doctor.