Congential Abnormalities Of The Kidney/cystic Kidneys Flashcards
Agenesis of the kidney
Can be unilateral or bilateral
- unilateral is less common but is compatible with life
- bilateral is more common and incompatible with life
if unilateral, the normal kidney will hypertrophy
Hypoplasia of the kidney
Can be bilateral or unilateral
- it’s observed in low birth weight infants and increases risk of CKD and renal failure lifelong
Ectopic kidneys
Due to ectopic foci developing
Kidneys can form anywhere but usually are around the pelvic brim at or around the renal arteries
- can increase likelihood of kinking or torsions of the ureters which increases risk of obstruction and bacterial infections
Horseshoe kidney
Found in 1:500/1000 people
Kidneys fuse either around the upper (10%) or lower poles (90%)
Usually wraps around the IMA and forms a U
Doesnt necessarily cause any symptoms and usually is benign
Double/ bifid ureters
Are usually unilateral and benign
Caused by either splitting completely of the metanephrogenic bud or bifid splitting before penetrating the renal mesenchyma
- double ureters almost always have associated distinct renal pelvis
Ureteropelvic junction obstruction
Congenital disorder that is most common cause of hydronephrosis in infants and children
- 20% bilateral and more often occur in males
Vesicoureteral reflux (VUR)
- *Most common and serious congenital anomaly of the bladder**
- also chronic VUR is the most common cause of chronic pyelonephritis
incompetence of the VUR is an important cause of ascending UTIs
Diverticula of the bladder
Vary in size from < 1 cm-10 cm
Most are acquired, however congenital ones may be due to focal failure of development of normal musculature or UT obstruction in fetal development
Can be asymptomatic but also not since they are sites for urinary stasis and predisposition of infections
Exstrophy of the bladder
Developmental failure of the anterior wall of the abdomen so the bladder now peaks out as an opened sac
Have increased risk of infections and adenocarinoma for lifetime
- surgically correctable in infancy
Urachal anomalies
1) Fistula = connects the bladder to the umbilicus
- allows for urine to excrete out of umbilicus
2) sinus = blind end pouch on the umbilicus
- does not show urine excretion of umbilicus
- no direct communication to bladder
3) cyst = blind end pouch as well that is connected to the median umbilical ligament
- does not show urine excretion
- no direct communication to bladder
- * cysts can develop into cancers (make up 20-40% of bladder adenocarcinoma)
Epispadias/ hypospadias
Hypospadias = ventral urethral opening of the penis
- more common (1:300)
- will results in urinary tract obstruction
- shows increased risk of ascending UTIs
Epispadias = dorsal urethral opening of the penis
Autosomal dominant polycystic kidney disease (ADPKD)
Adult form of cystic kidney disease
- causes symptoms and renal failure usually starting at 40-60 yrs of age
Common condition
- 1/400 - 1/1000 live births
- accounts for 5-10% of ESRD
Causes multiple expanding cysts in both kidneys and liver as well as increased berry aneurysms in the cerebral vasculature and 35% increases in MVP
Clinical features
- hematuria
- flank pain
- UTIs
- renal stones
- unexplained HTN
Defective gene is PKD1/2 on chromosome 16 which encodes polycystin-1 and/or 2
- 85% = PKD-1 and polycystic-1 defects
- 15% = PKD-2 and polycystic-2 defects
- ** this is why cystic kidney diseases are considered ciliopathy processes
Will kill eventually, but takes a long time, usually around 60s
- death is from uremia or HTN complications
Autosomal Recessive Polycystic kidney disease
Has 4 subcategories depending on time of presentation and whether hepatic fibrosis/lesions are present or not
- perinatal (most common)
- neonatal (most common)
- infantile
- juvenile
Caused by PKHD1 gene mutations occur chromosome translation 6p21-p23
- causes defective fibrocystin which leads to cystic development
Causes clinical features of renal and/or hepatic failure in childhood.
- if the children dont die = hepatic fibrosis and liver issues for life
What are the 3 subsets of nephronophthisis?
Sporadic/nonfamilial
Familial juvenile nephronophthisis (most common)
Renal-retinal dysplasia (15%)
are all autosomal recessive
Nephronophthisis
Is the most common cause of ESRD in children and young adults
Symptoms:
- polyuria and polydipsia always presents 1st
- growth retardation
- anemia
- extrarenal associations (retinal dystrophy, cerebellar abnormalities and ocular motor abnormalities)
- *should be strongly expected in children that have unexplained renal failure and chronic tubulointersitial nephritis on kidney biopsy**
Shows defective genetic defects on NPHP1-11 and JBTS2/3/9/11 genes
- causes defective nephrocystins which produces corticomedullary cysts and small kidneys
