**4. Autosomal recessive polycystic kidney disease (Potter type I)**

Definition: autosomal recessive polycystic kidney disease (ARPKD) is a bilateral renal anomaly caused by a gene disorder.

Incidence: 1:20,000–1:45,000.

Pathology: the PKHD1 gene on chromosome p21 [6] is generally accepted as a primary cause though the specific mechanism is not completely understood. Mutations are specific for individual families. The anomaly is characterized by convoluted tubes and collecting ducts often associated with liver fibrosis [4].

Ultrasound findings: ARPKD is characterized by kidney enlargement (>2SD above the mean for that gestational age) [4], increased echogenicity (resulting from the interference of the microcysts) [3], absent bladder, and oligoamnios (present from 16 weeks).

Differential diagnosis:


Ultrasound findings:

within the normal range [3].

oligoamnios is associated.

frequently the superior pole.

tion with the renal pelvis can be proved).

cerebro-reno-digital syndrome, VACTERL).

• Antenatal kidney monitoring is recommended.

**Figure 6.** Multicystic kidney (unilateral).

• Obstructive cystic dysplasia (more normal renal tissue visible).

• Risk of chromosomal anomalies is relatively low in unilateral forms (2–4%).

Differential diagnosis:

• Ureteral dilatation.

Clinical facts:

Unilateral (75–80%): the diagnostic is made in the presence of multiple cyst structure in the renal fossa, significantly larger than normal kidneys. The bladder is normal. Amniotic fluid is

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http://dx.doi.org/10.5772/intechopen.71925

Bilateral (20%): both kidneys are multicystic; the bladder cannot be visualized, and severe

Partial (rare): in rare cases of duplex kidney, only part of the kidney may be involved, more

• Hydronephrosis (distended calyces appear as cysts, but at attentive scrutiny communica-

• The risk for nonchromosomal syndromes is about 5–10% (branchio-oto-renal syndrome,

• Careful examination of the contralateral kidney (40% have an associated anomaly). • Genetic counseling and karyotyping are advised if associated anomalies are present.

• Conservative management is standard as most cases involute in the first years of life.

• Postnatal ultrasound evaluation is recommended every 6 months (**Figure 6**).

**Figure 5.** Autosomal recessive polycystic kidney disease.

Clinical facts:

