Congenital Abnormalities

Question 1

Kidneys [ascend/descend] during how many weeks of gestation?

Answer 1

ascend (from pelvis to upper retroperitoneum) at 6-9 weeks of gestation

Question 2

Kidney development occurs in 3 stages:

Answer 2

pronephros, mesonephros, metanephros

Question 3

_______ comes into contact with the cloaca and grows cranially as __________.

Answer 3

mesonephric duct; ureteric bud

Question 4

Horseshoe kidneys are most common in the [upper/lower] pole and get stuck beneath the _________ artery.

Answer 4

lower; inferior mesenteric

Question 5

True or false: Multicystic renal dysplasia is a developmental abnormality related to neoplasia/cancer.

Answer 5

False; it is a sporadic developmental abnormality.

Question 6

kidneys have the appearance of a bunch of grapes

Answer 6

multicystic renal dysplasia

Question 7

Which form of multicystic renal dysplasia is incompatible with life?

Answer 7

bilateral

Question 8

What are associated abnormalities associated with multicystic renal dysplasia?

Answer 8

uretero-pelvic junction obstruction, ureteral agenesis/atresia

Question 9

What are some of the histological features of multicystic renal dysplasia?

Answer 9

• non-communicating cysts of various size
• cysts separated by dysplastic parenchyma (disorganized with immature tubules, surrounded by condensed mesenchyme and cartilage)
• absence of a normal pelvocaliceal system*

Question 10

Why is bilateral multicystic renal dysplasia incompatible with life?

Answer 10

It causes secondary abnormalities in the lungs. Bilateral agenesis leads to absence of utero urine production and therefore oligohydramnios. This causes hypoplastic lungs (Potter’s syndrome).

Question 11

What is the characteristic appearance of a fetus with Potter’s syndrome?

Answer 11

• flat face w/ low set ears

- extremities with developmental defects

Question 12

What is the gene associated with Childhood Autosomal Recessive Polycystic Kidney Disease (ARPKD)?

Answer 12

PKHD1 (provides instructions for fibrocystin)

Question 13

What is the gross and microscopic pathology associated with ARPKD?

Answer 13

• gross: bilateral enlargement, reniform shape
• microscopic: dilated, elongated tubules at right angles to cortical surface; sponge-like appearance on cross-section; cysts in cortex and medulla; also see malformation of liver (cysts, portal fibrosis, proliferation of portal bile ducts)

Question 14

What is the typical clinical presentation of ARPKD?

Answer 14

renal and liver failure

Question 15

Is Adult Polycystic Kidney Disease (APKD) autosomal dominant or recessive?

Answer 15

autosomal dominant

Question 16

What is the typical clinical presentation of a patient with APKD?

Answer 16

• asymptomatic (or pain, depends)
• colic
• mass
• hemorrhage w/ hematuria
• progressive renal failure w/polyuria
• HTN
• low proteinuria

Question 17

Does APKD cause bilateral or unilateral abnormalities?

Answer 17

bilateral (all genetic causes=bilateral)

Question 18

Describe the genetics of APKD.

Answer 18

• High penetrance
• Genetically heterogeneous (chromosomes 16, 4, possible other)
• Abnormalities in cell differentiation
• Ciliopathy (defective mechanosensors)

Question 19

Which gene causes 85% of cases of APKD?

Answer 19

PKD1

Question 20

What is the prognosis for APKD?

Answer 20

renal failure in middle age or later life, depending on mutation

Question 21

What else can APKD cause, aside from renal complications?

Answer 21

• intracranial berry aneurysms (most serious possible complication)
• mitral valve prolapse