LMBBS Conference Houston 2006
Dr. Eileen Brewer
Renal Function

Disclaimer: These notes were taken by Ruth Dameron at the LMBBS Conference in Houston, June 17, 2006. There has been no attempt to verify accuracy. Do not quote the speakers based on these notes!

What are the kidney problems?
Why are they there?
What can be done to manage them?
What do normal kidneys do?
What do we know about kidney problems of BBS?
What is kidney failure, dialysis and transplant?

Every language has a different word for kidney.
English – kidney
Latin – ren (we call kidney disease renal diseases)
Greek – nephro (the study of kidneys is called nephrology)

The kidney is the master chemist of the body
   1. Disposes of waste products of daily metabolism
   2. Maintains water balance
   3. Produces renin, hormone which regulates bp
   4. Regulates body salts (Na, Cl, K)
   5. Regulates acid-base balance
   6. Regulates minerals (calcium, magnesium, phosphorous); interacts with glands and bones
   7. Produces active form of vitamin D from what is taken in in diet or skin
   8. Produces erythropoietin, a hormone that stimulates bone marrow to produce red blood cells and prevent anemia
   9. Removes drugs/medicines & toxins

Your kidney is the best sewage treatment plant ever designed!

Kidney disease can lead to:


   A. Bone disease or poor tooth development
   B. Rickets
   C. Resistance to growth hormone
   D. Edema (swelling) from mismanaging salts
   E. High blood pressure
   F. Anemia
   G. Dialysis or transplant ultimately

Kidney has a component called the nephron: filters blood; output is urine; leads to a tubule lined with different cells to do different things along the way. Finally collects the urine you want to get rid of and channels it to the ureter to the bladder.

Kidney problems in BBS:


Don’t know the incidence. If you don’t look very hard, probably 25%. If you screen everyone, it could be as high as 70 to 90%. But not everyone is looked at because not everyone has noticeable symptoms.

Mostly BBS causes structural abnormalities. It also causes some functional ones.
  • Renal cysts – any fluid filled sac in the tubule or nephron; can be microscopic or large; many hereditary diseases have renal cysts.
  • Multicystic – multiple cysts of varying sizes – most common abnormality in BBS
  • Polycystic is a completely different disease, not found in BBS (Dr. Nico disagrees. “BBS can cause the same kind of cyst as what is in polycystic disease.”)
  • Usually asymptomatic; can be confused with carcinoma; need CT scan
  • Fetal lobulations – fetus starts out with lobulation when young, smoothes out over time; but in BBS, it doesn’t smooth out.
  • Dysplasia, absent kidney, abnormally placed kidney – alternate ways in which the kidney is formed.
  • Doesn’t grow to normal size; often found as a small kidney; can be one or both of them;
    •       primitive filters
          primitive tubles
          cartilate and muscle tissues which don’t even belong there
          cysts are frequent – not enough normal kidney to get proper function
          kidney stones
          bladder reflux (vesicoureteral reflux)
          reflux means some urine goes UP when you void, not just down
          some never gets out and causes urinary tract infections and causes scars on the kidney
          diagnose with dye in bladder and watch which direction it go   ureteral duplication
          bladder problems needing catheters

    Kidney problems in BBS – what we know

    Somewhere between 25 to 70% have some kind of kidney issue – some are problematic; some are not.

    Sometimes they are seen in prenatal ultrasound, may look better by 2 years old but may not really be ok.

    To find, often won’t have certain symptoms,

  • need x-ray or ultrasound
  • 50-60% have high blood pressure
  • 10-50% chronic renal failure CRF


    • If there is end stage kidney failure – it’s time for dialysis or transplant.

    Hemodialysis – done in a dialysis center.
    Home peritoneal dialysis – done with a machine or manually with a special tube in the abdomen.


    Transplant

    How do you detect problems?
    Often no symptoms
    Polyuria (urinating frequently or a lot of quantity)
    Anemia
    Kidney or bladder infections
    Family history
    Positive prenatal ultrasound
    Only real way to find it by screening
    Blood pressure annually
    Urinalysis annually
    Blood test for anemia and kidney function annually
    Ultrasound