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There
are both common and rare genetic causes for kidney
stones.
Hypercalciuria:
One of the most common causes of kidney stones is
hypercalciuria. In this condition, the urine has
excessively high levels of calcium. Analysis
of family members with and without stones
demonstrates that this trait (i.e. elevated urinary
calcium concentrations) is passed from generation to
generation. There are likely several causes for
hypercalciuria and therefore probably different
genes involved. Since the majority of people with
calcium kidney stones have hypercalciuria, this is
one of the most common genetic defect(s) to cause
disease.
Hyperoxaluria:
This genetic disorder presents often during
childhood. There are two genetic defects known to
cause high urinary oxalate levels which can cause
kidney stones to be present at a young age. In Type
I primary hyperoxaluria there is a deficiency of
alanine glyoxylate aminotransferase. Often there is
deposition of calcium oxalate throughout the body.
In Type II disease the deficiency is D-glyceric
dehydrogenase. Treatment sometimes involves liver
(plus or minus) kidney transplant. If a liver
transplant is necessary, hopefully this is performed
prior to significant damage occurring to the
kidneys. Otherwise, a double transplant maybe
necessary.
Cystinuria:
This genetic
disorder leads in increased urinary cystine
concentrations. It accounts for 1-2% of kidney
stones. It is discussed in depth on the Cystine
Kidney Stone Page.
Polycystic
Kidney Disease: Polycystic
kidney disease is a genetic disorder in which
multiple cysts/blisters form in the kidney. It
can develop at different ages depending on the
genetic mutation. The causes of stone
formation in this disease are not completely
understood, but may include decreased urine flow in
the cystic areas and low urine citrate
concentrations.
Distal
Renal Tubular Acidosis (RTA):
RTA (renal tubular acidosis) refers to an inability
to excrete acid into the urine which is a normal
function of the kidneys. Each day through
eating, especially protein, people consume acid
which must be excreted into the urine. In certain
diseases, particularly autoimmune disorders such as
Sjogren's syndrome or primary biliary cirrhosis,
kidney damage can occur that prevents the kidney
from excreting acid. In other people an RTA is
a genetic disorder. In people with an RTA,
calcium stones, particularly calcium phoshate can
precipitate. Certain genetic forms can be associated
with rickets, hearing loss, and nephrocalcinosis
(calcium deposition in the kidney).
Hyperparathyroidism:
Hyperparathyroidism causes elevated blood calcium
levels which can lead to elevated urine calcium
levels and kidney stones. This is usually not
agenetic disorder. However, there is a rare genetic
disease known as multiendocrine neoplasm (MEN) which
can be
associated with hyperparathyroidism, kidney stones,
and
other endocrine organ abnormalities.
Uric
Acid Stones:
Hypoxanthine-guanine
phosphoribosyltransferase enzyme deficiency which is
sometimes associate with Lesch Nyhan syndrome causes
elevated uric acid levels and stones. A range of
diseases
associated with different degrees of enzyme
deficiency
occur.
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