Saudi Journal of Kidney Diseases and Transplantation

CASE REPORT
Year
: 2016  |  Volume : 27  |  Issue : 6  |  Page : 1242--1245

Autosomal dominant polycystic kidney disease in children


Kiran Chandra Patro, R Dilip, S Ramakrishnan 
 Department of Nephrology, NU Hospitals, Bengaluru, Karnataka, India

Correspondence Address:
Kiran Chandra Patro
Department of Nephrology, NU Hospitals, Padmanabhanagar, Bengaluru - 560 070, Karnataka
India

Abstract

Autosomal dominant polycystic kidney disease (ADPKD) presenting in adults is well documented, but the presentation in children is uncommon and is unclear why the disease presents early. Cases in children are identified usually while screening those with a strong family history and less commonly when symptomatic. We present here two children with ADPKD.



How to cite this article:
Patro KC, Dilip R, Ramakrishnan S. Autosomal dominant polycystic kidney disease in children.Saudi J Kidney Dis Transpl 2016;27:1242-1245


How to cite this URL:
Patro KC, Dilip R, Ramakrishnan S. Autosomal dominant polycystic kidney disease in children. Saudi J Kidney Dis Transpl [serial online] 2016 [cited 2020 Oct 30 ];27:1242-1245
Available from: https://www.sjkdt.org/text.asp?2016/27/6/1242/194680


Full Text

 Introduction



Autosomal dominant polycystic kidney disease (ADPKD) occur one in 400-1000 live births and accounts for approximately 5% of cases of end-stage renal disease (ESRD). [1],[2] Most patients with ADPKD present as adults but some present in childhood or even as early as in utero. Why some with ADPKD present in childhood is unclear. Although most children with ADPKD are asymptomatic (noted mainly while screening), those who do present in childhood have similar renal findings as those of affected adults. In contrast, the extrarenal manifestations of ADPKD commonly seen in adults (such as cysts in the liver and pancreas) are infrequently observed in pediatric patients. [3],[4] We present here two children who presented with renal symptoms and were diagnosed to have ADPKD.

 Case Reports



Case 1

An apparently asymptomatic 7-year-old boy, the first child of a nonconsanguineous couple, presented with painless macroscopic hematuria for two days. The evaluation revealed asymmetric kidneys with larger left kidney and bilateral renal cysts, both in cortex and medulla [Figure 1]. Hemorrhagic cortical cyst and larger cysts were noted in the left kidney. A small hepatic cyst was noted but no pancreatic cysts were noted. [Figure 2] Serum creatinine was 0.6 mg/ dL with estimated glomerular filtrate rate (GFR) (by Schwartz formula) of 89 mL/min/m 2 . Family screening revealed ADPKD in his mother (who was asymptomatic and had normal renal function) and his maternal grandmother who had renal dysfunction with ADPKD.{Figure 1}{Figure 2}

Case 2

An 11-year-old boy of nonconsanguineous parents presented with a history of headache and hypertension (140/90 mm Hg) for eight months. He had no urinary abnormality. Evaluation revealed normal sized kidneys with multiple bilateral renal cysts in both cortex and medulla and he had no further episodes of headache. There was no family history forthcoming and evaluation revealed ADPKD in his father, and he had normal renal function.

 Discussion



Although most pediatric patients with ADPKD are asymptomatic and cysts are usually noted when screening those with strong family history of ADPKD, some of them are detected when symptomatic, as in our cases. The presentation [Figure 3] and [Figure 4]. Serum creatinine was 0.6 mg/dL and estimated glomerular filtration rate 89 mL/min/m 2 . He was initiated on angiotensin receptor blocker and follow-up for one year revealed normal blood pressure and creatinine of 0.8 mg/dL. Cardiac evaluation was normal, of ADPKD varies with a clinical spectrum ranging from rare neonatal presentation with large hyperechoic kidneys to renal cysts found accidentally during the evaluation for nonrenal abdominal symptoms or by ultrasound screening of children with positive family history. They can present with gross or microscopic hematuria, hypertension, proteinuria, infection of the cyst, abdominal/flan/back pain, and renal dysfunction (rarely). These patients usually have no extra renal manifestations of ADPKD, which are commonly seen in adults (example: cysts in the liver and pancreas). [2],[3],[4]{Figure 3}{Figure 4}

Why some of these individuals present so early in childhood is unclear because there is no evidence for genetic heterogeneity when affected children are compared with those who present in adulthood. Second hit theory where somatic "second hit" mutation in another allele in patients harboring germline mutation in PKD gene, heritable unstable gene, or contiguous gene syndrome has been proposed as mechanisms for the early presentation of ADPKD in children. [1],[4],[5]

Renal involvement is characterized by cystic dilatations in all parts of the nephron including Bowman's space and all tubular segments. In the early stages, there may be only a few macrocysts irregularly distributed. Approximately 17% of children with ADPKD will demonstrate unilateral renal findings at initial screening. Later, both kidneys become enlarged due to the formation of macrocysts in the cortex and in the medulla. Cerebral vessel malformations have also been rarely described in children with ADPKD.

Although the nonrenal manifestations in children are less common, cardiac changes have been reported in some. Increased left ventricular mass and prolonged isovolumetric relaxation time have been reported in early stages of ADPKD in normotensive children. [5]

Diagnosis is easy in symptomatic children who have a strong family history with demonstration of renal cysts, which is noted bilaterally usually. Ultrasonographic finding of echogenic kidneys without macroscopic cysts as noted in infants, to the presence of even a single cyst in at-risk children is enough for diagnosis of ADPKD in children. In those with no family history, there have been no absolute criteria as in adults for the number of cysts to diagnose ADPKD and hence may warrant genetic studies.

Renal insufficiency generally does not develop until adulthood. In fact, children with ADPKD have been noted to have increased GFR. Although the general progression of the disease to ESRD seems to be the same as in adults, it has been reported that those who are symptomatic before 30 years will progress faster to ESRD. The rate of symptoms increases with severity of renal involvement and disease progression (defined as an increase in the number of cysts and increased renal volume by ultrasound). Early onset of the disease, male gender, and hypertension seem to be the risk factors for progression of the kidney disease and renal dysfunction.

As there is no specific treatment to prevent or delay progression of renal structural disease in ADPKD, management should be mainly directed at blood pressure control (mainly with angiotensin converting enzyme inhibitors), prompt treatment of urinary tract infections, and need to restrict nephrotoxic agents. The individualistic approach in children, need to avoid contact sports (if there is gross nephromegaly), and adequate fluid intake may need to be emphasized. Vasopressin receptor antagonists and mammalian target of Rapamycin signaling pathway inhibitors are under clinical trials and use in children, but benefits are not proven. [5]

To conclude, ADPKD in children although uncommon is a definite entity which needs a systematic approach, treatment, and long-term follow-up.

Conflict of interest: None declared.

References

1Gal A, Wirth B, Kääriäinen H, et al. Childhood manifestation of autosomal dominant polycystic kidney disease: No evidence for genetic heterogeneity. Clin Genet 1989;35:13-9.
2Fick GM, Duley IT, Johnson AM, Strain JD, Manco-Johnson ML, Gabow PA. The spectrum of autosomal dominant polycystic kidney disease in children. J Am Soc Nephrol 1994; 4:1654-60.
3Mekahli D, Woolf AS, Bockenhauer D. Similar renal outcomes in children with ADPKD diagnosed by screening or presenting with symptoms. Pediatr Nephrol 2010;25:2275-82.
4Fick GM, Johnson AM, Strain JD, et al. Characteristics of very early onset autosomal dominant polycystic kidney disease. J Am Soc Nephrol 1993;3:1863-70.
5Niaudet P, Mattoo TK, Kim MS. Autosomal Dominant Polycystic Kidney Disease in Children, Up to Date, 2013. Available from: http://www.uptodate.com/contents/autosomal-dominant-polycystic-kidney-disease-in-children. Last accessed 13 October 2016.