What congenital anomalies are commonly associated with urinary tract malformations? (List at least 6)
Low-set/malformed ears, sensorineural deafness, chromosomal disorders (trisomy 13 & 18), absent abdominal muscles (prune belly), vertebral/extremity anomalies, imperforate anus, renal/extrarenal tumors, ocular abnormalities, hepatic cysts or cirrhosis.
Distinguish between renal aplasia, hypoplastic kidneys, and renal dysplasia.
Renal aplasia= kidneys completely absent/don’t develop. Hypoplastic= small kidneys with decreased nephrons ( unilateral or bilateral). Dysplasia= abnormal tissue differentiation with primitive glomeruli/tubules, cysts, and nonrenal tissue ( ex. cartilage)
What genes are mutated in autosomal dominant PKD, and what chromosomes are they on?
PKD-1 (chromosome 16) and PKD-2 (chromosome 4). Causes cyst formation, obstruction, destruction of renal parenchyma, interstitial fibrosis, and loss of functional nephrons.
What is autosommal recessive PKD (ARPKD) and how does it differ from the dominant form?
ARPKD involves cystic changes in both the kidney AND liver, caused by gene mutation. Requires renal replacement therapy during childhood or adolescence (earlier onset than ADKPD).
Compare unilateral vs. bilateral renal agenesis (Potter Syndrome).
Unilateral= usually left kidney absent; remaining kidney hypertrophies; can live normally. Bilateral (Potter syndrome)= incompatible with extrauterine life; associated with facial anomalies (wide-set eyes, parrot-beak nose, low-set ears, receding chin).
What are urethral valves and who do they affect?
Thin membranes that occlude the urethral lumen and obstruct urinary outflow. Occur in male infants. Treatment: prenatal bladder shunting or resection in the first days of life.
Distinguish hypospadias from epispadias.
Hypospadias= urethral meatus on the ventral (under) surface of the penis; treated with surgery. Epispadias= urethral opening on the dorsal surface in males; females have a cleft along the ventral urethra extending to bladder neck. Twice as many males affected.
What is bladder exstrophy and when must it be repaired?
Herniation of the bladder through the abdominal wall due to failure of abdominal muscles, pelvic ring, and pelvic floor musculature to fuse at the midline. Bladder and pubic defect should be closed within 72 hours of birth; surgical reconstruction within the first year.
What is poststreptococcal glomerulonephritis (PSGN)? Who gets it and what causes it?
Glomerulonephritis occuring after a throat or skin infection with group A a-hemolytic streptococci. Antigen-antibody complexes and complement deposit in the glomerulus leads to inflammation and injury. Mainly affects children ages 5-15.
What are the clinical manifestations and treatment of PSGN?
Manifestations: sudden hematuria, edema, hypertension. Treatment: restrict fluids, sodium and potassium; administer antihypertensives and diuretics.
What is Henoch-Schonlein purpura nephitis (HSP) and what are its 4 classic clinical manifestations?
IgA vasculitis causing glomerular blood vessel inflammation. Classic 4: palpable purpura, arthritis, abdominal pain, and renal disease (hematuria with or without mild proteinuria).
What are the 4 hallmark findings of nephrotic syndome?
Proteinuria, hypoalbuminemia, hyperlipidemia, and edema.
Distinguish minimal change nephropathy (MCN) from focal segmental glomerulosclerosis (FSGS).
MCN= fusion of podocyte foot processes. FSGS= effacement (thinning/deletion) of podocytes with significant increase in pore size. Both can be primary (idiopathic) or secondary.
What causes congenital nephrotic syndrome (Finnish type) and why is it unique?
Autosomal recessive mutation of NPHS1 gene that leads to a lack of nephrin at the pondocyte slit membrane that leads to proteinuria. Presents before 3 months of life. Does NOT respond to steroid treatment.
What are the clinical manifestions of nephrotic syndrome in children?
Periorbital edema, edema of intestinal mucosa, signs of malnourishment, increased susceptibility to infection, irritability, fatigue, lethargy.
What is the treatment plan for nephrotic syndrome? (List at least 6 elements)
Reduce protein excretion, prevent/treat infection, glucocorticosteroids (predisone), low- sodium diet, skin care, diuretics (furosemide, metolazone) if edema is problematic, ACE inhibitors, noncorticosteroidal immunosuppressives.
What is HUS, what causes it, and what age group does it primarily affect?
Hemolytic Uremic Syndrome- most common community-acquired cause of acute renal failure in children, mostly < 4 years old. Caused by E. Coli O 157:H7; bacterial toxin damages RBCs and endothelial cells- arterioles swell and occlude with fibrin clots.
Walk through the pathophysiology of HUS step by step.
E. coli toxin damages RBCs and enothelial cells- glomerular arterioles swell and occlude with fibrin clots- decreased GFR, hematuria, proteinuria- swollen vessels damage passing RBCs- spleen removes damaged RBCs- hemolytic anemia- microcirculation develops thrombi.
What are the clinical manifestations and treatment of HUS?
Manifestations: preceded by GI promdrome with diarrhea, then sudden pallor, bruising/purpura, irritability, oliguria- renal failure. Treatment: maintain nutrition/hydration (dilute toxins), control HTN/hyperkalemia/seizures, dialysis if needed, packed RBC transfusions. Most children recover.
How do UTI presentations differ between infants and older children?
Infants: fever, vomiting, diarrhea, jaundice, or fever of undetermined origin. Older children: frequency, urgency, enuresis/incontinence in a previously dry child, abdominal/flank/back pain, fou-smelling urine, hematuria.
What is vesicoureteral reflux (VUR), and how is it diagnosed, and how is it graded?
Retrograde flow of urine from bladder into ureters/kidneys- sweeps infected urine up- frequent pyelonephritis. Caused by congenital abnormality or ectopic ureteral insertion. Diagnosed by VCUG and IVP. Graded I - V.
What is the treatment for VUR?
Prompt treatment of UTIs. Recurrent infection or high-grade reflux: surgical intervention or endoscopic injection of biomaterials into bladder wall below the ureteral orifice.
Define enuresis and distinguish primary from secondary enuresis.
Enuresis= bedwetting at night in a child > 5 years old. Primary= child has never been continent. Secondary= child was previously continent but has become incontinent again.
What are the treatment options for daytime incontinence vs. enuresis?
Daytime incontinence: behavioral theraphy (timed voding), fluid management, treat constipation/UTIs, anticholingergic or a-blocker medications. Enuresis: enuresis alarms, desmopressin acetate tablets.
