Chapter 33 Disorders of Renal Function
Kidneys are subject to many of the same types of disorders that affect other body structures such
as developmental defects, infections, altered immune responses and neoplasms.
Fetal kidneys begin producing urine by week 13 gestation, main constituent of amniotic fluid.
---Anomalies of fetal kidneys include shape and position (most common) and (less common)
disorders involving decrease in renal mass (agenesis, hypoplasia) or change in renal structure
(renal cysts).
-Agenesis: rare condition in which newborn’s kidneys fail to develop (unilateral or bilateral)
-Hypoplasia: kidneys do not develop to normal size and contain fewer renal lobes
-Dysplasia: causes by abnormality in the differentiation of kidney structures during embryonic
development
Potter Syndrome
Characteristic facial features of newborns with renal agenesis due to oligohydramnios (small
amount of amniotic fluid): eyes are widely separated and have epicanthic folds, low set ears,
broad and flat nose, receding chin, as well as limb defects.
Causes of neonatal renal failure with potter phenotype: cystic renal dysplasia, obstructive
uropathy, autosomal recessive polycystic disease, unilateral agenesis (uncommon)
Cystic Disease of the Kidney
- Fluid-filled sacs or segments of a dilated nephron
-Causes: tubular obstructions that increase intratubular pressure, changes in the basement
membrane of the renal tubules that predispose to cystic dilatation
-Types of cystic kidney disease
a. Simple and acquired renal cysts (common; usually <1cm in size; do not produce
signs/symptoms (but hematuria, flank pain, infection and hypertension related ischemia);
(ESRD on dialysis can have acquired renal cysts)
b. Medullary cystic disease (hereditary onset during childhood, cysts present in medullary
portion of kidney, renal atrophy, eventual kidney failure)
c. Polycystic kidney disease (single gene disorder transmitted through Mendelian patterns)
Autosomal recessive polycystic kidney disease (characterized by cystic
transformation of collecting ducts; presents as severe renal dysfunction in infancy,
Fig 33-3B, pg 864)
Autosomal dominant polycystic kidney disease (results in formation of numerous
fluid filled cysts in tubular structures of both kidneys with threat of progression to
chronic renal failure; may include HTN, cardiovascular abnormalities, cerebral
aneurysms, cyst in liver and pancreas-Fig 33-3A, pg 864)
Urinary Tract Obstruction
Cause: Developmental defects, calculi (stones), pregnancy, benign prostatic hyperplasia (BPH),
scar tissue resulting from infection and inflammation, tumors or neurologic disorders such as
spinal cord injury (Fig 33-4, pg 866 and table 33-1, pg 867)
Kidneys are subject to many of the same types of disorders that affect other body structures such
as developmental defects, infections, altered immune responses and neoplasms.
Fetal kidneys begin producing urine by week 13 gestation, main constituent of amniotic fluid.
---Anomalies of fetal kidneys include shape and position (most common) and (less common)
disorders involving decrease in renal mass (agenesis, hypoplasia) or change in renal structure
(renal cysts).
-Agenesis: rare condition in which newborn’s kidneys fail to develop (unilateral or bilateral)
-Hypoplasia: kidneys do not develop to normal size and contain fewer renal lobes
-Dysplasia: causes by abnormality in the differentiation of kidney structures during embryonic
development
Potter Syndrome
Characteristic facial features of newborns with renal agenesis due to oligohydramnios (small
amount of amniotic fluid): eyes are widely separated and have epicanthic folds, low set ears,
broad and flat nose, receding chin, as well as limb defects.
Causes of neonatal renal failure with potter phenotype: cystic renal dysplasia, obstructive
uropathy, autosomal recessive polycystic disease, unilateral agenesis (uncommon)
Cystic Disease of the Kidney
- Fluid-filled sacs or segments of a dilated nephron
-Causes: tubular obstructions that increase intratubular pressure, changes in the basement
membrane of the renal tubules that predispose to cystic dilatation
-Types of cystic kidney disease
a. Simple and acquired renal cysts (common; usually <1cm in size; do not produce
signs/symptoms (but hematuria, flank pain, infection and hypertension related ischemia);
(ESRD on dialysis can have acquired renal cysts)
b. Medullary cystic disease (hereditary onset during childhood, cysts present in medullary
portion of kidney, renal atrophy, eventual kidney failure)
c. Polycystic kidney disease (single gene disorder transmitted through Mendelian patterns)
Autosomal recessive polycystic kidney disease (characterized by cystic
transformation of collecting ducts; presents as severe renal dysfunction in infancy,
Fig 33-3B, pg 864)
Autosomal dominant polycystic kidney disease (results in formation of numerous
fluid filled cysts in tubular structures of both kidneys with threat of progression to
chronic renal failure; may include HTN, cardiovascular abnormalities, cerebral
aneurysms, cyst in liver and pancreas-Fig 33-3A, pg 864)
Urinary Tract Obstruction
Cause: Developmental defects, calculi (stones), pregnancy, benign prostatic hyperplasia (BPH),
scar tissue resulting from infection and inflammation, tumors or neurologic disorders such as
spinal cord injury (Fig 33-4, pg 866 and table 33-1, pg 867)
