Bladder Agenesis and Bilateral Ectopic Ureters in an Infant Male With Cystic Renal Dysplasia, Imperforate Anus, and Penoscrotal Transposition

Bladder agenesis is a rare congenital anomaly infrequently reported in the literature, with an incidence of 1/600,000 patients.¹ Commonly associated with other fatal malformations, the condition is often incompatible with life.² Prior reports estimate that over 90% of living children born with this malformation are female, owing to renal preservation resulting from low pressure drainage of urine into the vagina, uterus, and vestibule.^3,4 Herein we report a rare case of an infant male born with penoscrotal transposition and end stage renal disease secondary to bilateral cystic renal dysplasia found to have concurrent bladder agenesis and bilateral ureteral ectopia.

Multi-parametric MRI of kidney disease progression for autosomal recessive polycystic kidney disease: mouse model and initial patient results

BACKGROUND

Autosomal recessive polycystic kidney disease (ARPKD) is a rare but potentially lethal genetic disorder typically characterized by diffuse renal microcysts. Clinical trials for patients with ARPKD are not currently possible due to the absence of sensitive measures of ARPKD kidney disease progression and/or therapeutic efficacy.

METHODS

In this study, animal and human magnetic resonance imaging (MRI) scanners were used to obtain quantitative kidney T1 and T2 relaxation time maps for both excised kidneys from bpk and wild-type (WT) mice as well as for a pediatric patient with ARPKD and a healthy adult volunteer.

RESULTS

Mean kidney T1 and T2 relaxation times showed significant increases with age (p < 0.05) as well as significant increases in comparison to WT mice (p < 2 × 10-10). Significant or nearly significant linear correlations were observed for mean kidney T1 (p = 0.030) and T2 (p = 0.054) as a function of total kidney volume, respectively. Initial magnetic resonance fingerprinting assessments in a patient with ARPKD showed visible increases in both kidney T1 and T2 in comparison to the healthy volunteer.

CONCLUSIONS

These preclinical and initial clinical MRI studies suggest that renal T1 and T2 relaxometry may provide an additional outcome measure to assess cystic kidney disease progression in patients with ARPKD.

IMPACT

A major roadblock for implementing clinical trials in patients with ARPKD is the absence of sensitive measures of ARPKD kidney disease progression and/or therapeutic efficacy. A clinical need exists to develop a safe and sensitive measure for kidney disease progression, and eventually therapeutic efficacy, for patients with ARPKD. Mean kidney T1 and T2 MRI relaxation times showed significant increases with age (p < 0.05) as well as significant increases in comparison to WT mice (p < 2 ×10-10), indicating that T1 and T2 may provide sensitive assessments of cystic changes associated with progressive ARPKD kidney disease. This preclinical and initial clinical study suggests that MRI-based kidney T1 and T2 mapping could be used as a non-invasive assessment of ARPKD kidney disease progression. These non-invasive, quantitative MRI techniques could eventually be used as an outcome measure for clinical trials evaluating novel therapeutics aimed at limiting or preventing ARPKD kidney disease progression.

Giant choledochal cyst and infantile polycystic kidneys as prenatal sonographic features of Caroli syndrome

Caroli syndrome is a developmental disorder caused by complete or partial arrest of ductal plate remodeling, leading to dilated bile ducts along with fibrosis surrounding the portal tracts. It is most commonly associated with autosomal recessive polycystic kidney (ARPKD). We report a unique case of Caroli syndrome, diagnosed prenatally at 24 weeks of gestation in a 29-year-old Thai woman. Ultrasound findings revealed the association of a fetal giant choledochal cyst with ARPKD. Autopsy findings showed ductal plate malformation, typical of Caroli syndrome, associated with giant choledocal cyst and ARPKD.

Diffusion tensor imaging of the kidney in healthy controls and in children and young adults with autosomal recessive polycystic kidney disease

OBJECTIVE

To compare diffusion tensor imaging (DTI) of the kidneys and its derived parameters in children with autosomal recessive polycystic kidney disease (ARPKD) versus healthy controls.

METHODS

In a prospective IRB-approved study, we evaluated the use of DTI to compare kidney parenchyma FA values in healthy controls (age-matched children with no history of renal disease) versus patients with ARPKD. A 20-direction DTI with b-values of b = 0 s/mm² and b = 400 s/mm² was used to acquire data in coronal direction using a fat-suppressed spin-echo echo-planar sequence. Diffusion Toolkit and TrackVis were used for analysis and segmentation. TrackVis was used to draw regions of interest (ROIs) covering the entire volume of the renal parenchyma, excluding the collecting system. Fibers were reconstructed using a deterministic fiber tracking algorithm. The FA values based on the ROI data, mean length, and volume of the tracks based on the fiber tracking data were recorded.

RESULTS

Eight healthy controls (mean age = 12.9 years ± 4.0; 1/8 males) and six ARPKD participants (mean age = 13.8 years ± 8.5; 5/6 males) were included in the study. Compared to healthy controls, patients with ARPKD had significantly lower FA values (0.33 ± 0.03 vs. 0.25 ± 0.02, p = 0.002) and mean track length (16.73 ± 3.43 vs. 11.61 ± 1.29 mm, p = 0.005).

CONCLUSION

DTI of the kidneys shows significantly lower FA values and mean track length in children and young adults with ARPKD compared to normal subjects. DTI of the kidney offers a novel approach for characterizing renal disease based on changes in diffusion anisotropy and kidney structure.

Prospective Evaluation of Kidney Disease in Joubert Syndrome

BACKGROUND AND OBJECTIVES

Joubert syndrome is a genetically heterogeneous ciliopathy associated with >30 genes. The characteristics of kidney disease and genotype-phenotype correlations have not been evaluated in a large cohort at a single center.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We evaluated 97 individuals with Joubert syndrome at the National Institutes of Health Clinical Center using abdominal ultrasonography, blood and urine chemistries, and DNA sequencing.

RESULTS

Patients were ages 0.6-36 years old (mean of 9.0±7.6 years old); 41 were female. Mutations were identified in 19 genes in 92 patients; two thirds of the mutations resided in six genes: TMEM67, C5orf42, CC2D2A, CEP290, AHI1, and KIAA0586. Kidney disease was detected in 30%, most commonly in association with the following genes: CEP290 (six of six), TMEM67 (11 of 22), and AHI1 (three of six). No kidney disease was identified in patients with mutations in C5orf42 (zero of 15) or KIAA0586 (zero of six). Prenatal ultrasonography of kidneys was normal in 72% of patients with kidney disease. Specific types of kidney disease included nephronophthisis (31%), an overlap phenotype of autosomal recessive polycystic kidney disease/nephronophthisis (35%), unilateral multicystic dysplastic kidney (10%), and indeterminate-type cystic kidney disease (24%). Early-onset hypertension occurred in 24% of patients with kidney disease. Age at ESRD (n=13) ranged from 6 to 24 years old (mean of 11.3±4.8 years old).

CONCLUSIONS

Kidney disease occurs in up to one third of patients with Joubert syndrome, most commonly in those with mutations in CEP290, TMEM67, and AHI1. Patients with mutations in C5orf42 or KIAA0586 are less likely to develop kidney disease. Prenatal ultrasonography is a poor predictor of kidney involvement in Joubert syndrome. Unilateral multicystic dysplastic kidney and autosomal recessive polycystic kidney disease-like enlarged kidneys with early-onset hypertension can be part of the Joubert syndrome kidney phenotype.

An Empirical Biomarker-Based Calculator for Cystic Index in a Model of Autosomal Recessive Polycystic Kidney Disease-The Nieto-Narayan Formula

Autosomal recessive polycystic kidney disease (ARPKD) is associated with progressive enlargement of the kidneys fuelled by the formation and expansion of fluid-filled cysts. The disease is congenital and children that do not succumb to it during the neonatal period will, by age 10 years, more often than not, require nephrectomy+renal replacement therapy for management of both pain and renal insufficiency. Since increasing cystic index (CI; percent of kidney occupied by cysts) drives both renal expansion and organ dysfunction, management of these patients, including decisions such as elective nephrectomy and prioritization on the transplant waitlist, could clearly benefit from serial determination of CI. So also, clinical trials in ARPKD evaluating the efficacy of novel drug candidates could benefit from serial determination of CI. Although ultrasound is currently the imaging modality of choice for diagnosis of ARPKD, its utilization for assessing disease progression is highly limited. Magnetic resonance imaging or computed tomography, although more reliable for determination of CI, are expensive, time-consuming and somewhat impractical in the pediatric population. Using a well-established mammalian model of ARPKD, we undertook a big data-like analysis of minimally- or non-invasive blood and urine biomarkers of renal injury/dysfunction to derive a family of equations for estimating CI. We then applied a signal averaging protocol to distill these equations to a single empirical formula for calculation of CI. Such a formula will eventually find use in identifying and monitoring patients at high risk for progressing to end-stage renal disease and aid in the conduct of clinical trials.

Meckel-Gruber syndrome: pathologic manifestations, minimal diagnostic criteria, and differential diagnosis

This article provides an overview of the major pathologic manifestations of Meckel-Gruber syndrome, current knowledge about its pathogenesis, minimal diagnostic criteria, and differential diagnosis. Typical sonographic findings (occipital encephalocele, postaxial polydactyly, and cystic enlargement of the kidneys) allow for diagnosis of most cases before the 14th week of gestation, but the pathologist may encounter clinically unsuspected or atypical cases that require morphologic confirmation. In these cases, a meticulous autopsy is necessary to establish the diagnosis of Meckel-Gruber syndrome.

Unusual sonographic features of ARPKD

The classic sonographic appearance of the kidneys in fetuses with autosomal recessive polycystic kidney disease (ARPKD) has been well described. We report a case of enlarged kidneys with pyramidal hyperechogenicity quite similar to medullary nephrocalcinosis found in a fetus at 34 weeks' gestation. At 39 weeks, a female neonate was delivered and died after 22 h due to pulmonary insufficiency secondary to severe oligohydramnios. On pathological analysis, the gross and microscopic findings were typical of ARPKD with diffuse dilatation of tubules throughout. The fetal renal lobulation was prominent and on section, the pyramids were delineated within each lobule, accounting for the clear image of the pyramids observed on sonography.

The role of ultrasound in renal insufficiency: the essentials

Sonography is the best screening modality to evaluate patients presenting with renal insufficiency. Ultrasound findings can be normal in patients with renal disease, especially in prerenal azotemia and acute parenchymal renal disease. Echogenic kidneys indicate the presence of parenchymal renal disease; the kidneys may be of a normal size or enlarged. Small kidneys suggest advanced stage chronic kidney disease. Uncommonly, cystic disease of the kidney, especially adult type polycystic kidney disease may be the cause of the patient's renal insufficiency with bilaterally enlarged kidneys containing multiple cysts of various sizes. If hydronephrosis is present, the level and cause of the obstruction should be sought. When ultrasound cannot diagnose the level and cause of obstruction, other imaging modalities, including CT and MRI may be useful. When renovascular disease (arterial stenosis or venous thrombosis) is suspected, spectral and color Doppler can be useful in detecting abnormalities.

High-Resolution Renal Sonography in Children with Autosomal Recessive Polycystic Kidney Disease

OBJECTIVE

Our objective was to describe the spectrum of renal findings using a high-frequency linear array transducer in patients with autosomal recessive polycystic kidney disease (ARPKD).

CONCLUSION

There is a spectrum of findings in the kidney in patients with ARPKD that is very well depicted using the high-resolution technique described in this article.

Combination treatment of PKD utilizing dual inhibition of EGF-receptor activity and ligand bioavailability

BACKGROUND

We have previously demonstrated an essential role for increased epidermal growth factor receptor (EGFR) activity in mediating renal cyst formation and biliary ductal ectasia (BDE) in murine models of autosomal-recessive polycystic kidney disease (ARPKD) such as the BPK mouse. The current study was designed to determine (1). if treatment with a second-generation inhibitor of EGFR tyrosine kinase activity, EKB-569, was effective in treatment of ARPKD; (2). if tyrosine kinase inhibitor therapy used in combination with pharmacologic reduction of the availability of transforming growth factor-alpha (TGF-alpha), using WTACE2, could provide improved therapeutic efficacy and/or decrease potential toxicity; and (3). if effectiveness of treatment could be monitored noninvasively in murine ARPKD models by use of serial ultrasonography.

METHODS

BPK litters were treated with EKB-569 by intraperitoneal injection from postnatal day 7 to postnatal day 21. EKB-569's effectiveness alone or in combination with WTACE2 was measured by reduction in kidney weight/body weight ratios, morphometric renal cystic index, and evaluation of renal function. Renal ultrasound was performed on normal and cystic animals, under different therapeutic regimens, utilizing a 15 mHz linear array transducer, and ultrasound data were compared with histology and renal functional data.

RESULTS

Treatment of BPK mice with EKB-569 alone resulted in a marked reduction of kidney weight/body weight ratios, dramatically reduced collecting tubule cystic index, as well as BDE, and improved renal function. The combined treatment with EKB-569 and WTACE2 permitted a 67% reduction in EKB-569 dosage necessary to achieve results equivalent to those produced with EKB-569 alone. Untreated cystic animals died of renal failure, on average, at postnatal day 24 with a collecting tubule cystic index of 4.8, significant BDE, and maximal urine osmolarity of 361 mOsm. Cystic animals treated with EKB-569 and WTACE2 to postnatal day 21 were alive and well with normal renal function, a reduced collecting tubule cystic index of 1.7 (P < 0.02), improvement in BDE, and a threefold increase in maximum urinary concentrating ability (P < 0.01). Renal ultrasound could reliably detect cystic kidneys as early as postnatal day 7 and the natural history as well as effects of therapeutic intervention were clearly delineated by ultrasound evaluation.

CONCLUSION

This study demonstrates that in murine ARPKD (1). EKB-569 is as effective as first-generation EGFR tyrosine kinase inhibitors in reducing cyst formation and preserving renal function; (2). combination therapy with EKB-569 and WTACE2 provides maximum efficacy in improving renal and biliary abnormalities, at lower doses, thereby minimizing potential toxicity; and (3). renal ultrasound provides a simple, reliable, noninvasive method of following natural history and effect of treatment regimens.

Prenatal ultrasonographic diagnosis of a recurrent case of Johanson-Blizzard syndrome

We report on ultrasonographic prenatal diagnosis of a recurrent case of Johanson-Blizzard syndrome. The pregnancy was terminated at 21 weeks'. This observation highlights the great variability of the expression of this syndrome, including in the same family, and the necessity of collaborating with an experienced geneticist in all antenatal diagnosis of any complex of abnormalities.

Autosomal recessive polycystic kidney disease: outcomes from a single-center experience

Autosomal recessive polycystic kidney disease (ARPKD) is a relatively common form of pediatric polycystic kidney disease with an incidence of 1:20,000 live births. Previous reports, primarily from populations of European origin, indicate that the clinical presentation and disease course are quite variable. Using a retrospective study design, we sought to determine whether the clinical course and outcome of our multi-ethnic patient cohort differs from the published literature. A 10-year (1990-2000) retrospective study was conducted in which we reviewed the clinical, histopathological, and imaging records of our 31 ARPKD patients. Patients were diagnosed between 0 and 14 years of age, with 17 (55%) presenting within the 1st month of life. The mean follow-up was 67 months and age at last follow-up ranged from 0.5 to 16 years. Of the 17 patients diagnosed as neonates, 11 (65%) had respiratory insufficiency complicated by pneumothoraces. Two died shortly after birth and 2 died within the 1st year of life due to respiratory failure. Among the 13 neonatal survivors, 7 (54%) developed progressive renal insufficiency, whereas 6 of 14 (43%) of those children who presented beyond 1 month of age developed renal insufficiency. Hypertension was present in 55% of our patients, with nearly all neonatal survivors requiring antihypertensive management. Evidence of portal hypertension was found in 10 (37%) of the 27 patients who survived the 1st year of life. In our multi-ethnic ARPKD cohort, the 1-year survival rate (87%) and the clinical variability are comparable to those previously reported. With the recent identification of the PKHD1 gene, characterization of disease-causing mutations should provide new insights into the molecular basis for this phenotypic variability.

Sonography of macrocysts in infantile polycystic kidney disease

The typical sonographic appearance of autosomal recessive polycystic kidney disease (ARPKD) has been described as symmetrically enlarged, echogenic kidneys with occasional visualization of small cysts. Modern sonographic equipment, however, allows a greater ability to show parenchymal detail, and multiple tiny cysts and occasionally dilated tubular structures have become apparent. In this report, we describe sonographic findings of ARPKD that are quite similar to the macroscopic appearance. Sonographic images show unusual focal rosettes consisting of a cluster of the radially oriented, dilated collecting tubules that are apparent on pathologic evaluation. It is important to recognize the focal rosette as a manifestation of ARPKD.

The value of radionuclide studies in children with autosomal recessive polycystic kidney disease

PURPOSE

To describe and analyze the appearances of autosomal recessive polycystic kidney disease (ARPKD) on Tc-99m DMSA and Tc-99m HIDA scintigraphy.

MATERIALS AND METHODS

The authors evaluated scintigraphic findings for 13 boys and 9 girls (age range, 2 months to 22.75 years; mean, 7.5 years) with ARPKD. Fourteen children underwent Tc-99m DMSA and 20 underwent Tc-99m HIDA scintigraphy according to European guidelines. Kidney outline, internal structure, tracer uptake, and differential function were analyzed on Tc-99m DMSA images, whereas relative liver lobe sizes, hepatocyte tracer uptake, time to peak, and excretion into the biliary tree and gut were evaluated on Tc-99m HIDA scans.

RESULTS

On Tc-99m DMSA images, loss of kidney outline and internal structure was seen in 75% of the scans, and patchy tracer uptake with focal defects throughout the kidneys, particularly at the poles, was evident in 93%. In 85% of the cases, the Tc-99m DMSA changes did not correlate with the ultrasonographic findings where the kidneys are uniformly affected. Characteristic findings on Tc-99m HIDA scans were enlarged left liver lobe in 80%, a delay in maximal hepatocyte uptake in 68%, delayed tracer excretion into the biliary tree in 32% (with stasis in the prominent intrahepatic biliary ducts in 50% or pooling into the segmentally dilated biliary ducts in 25%), and delayed excretion into the gut in 40% of patients.

CONCLUSIONS

In a child with clinically enlarged kidneys that appear diffusely hyperechoic on ultrasound, the appearances on Tc-99m DMSA imaging strongly support the diagnosis of ARPKD. The Tc-99m HIDA findings, especially of an enlarged left lobe of the liver with bile stasis or dilatation, further support the diagnosis.

Hereditary polycystic kidney diseases in children: changing sonographic patterns through childhood

OBJECTIVE

To determine which US changes occur with time in children affected by autosomal recessive (ARPKD) and autosomal dominant polycystic kidney disease (ADPKD) and whether any of these changes correlate with the onset of renal failure.

MATERIALS AND METHODS

We reviewed the US features of 29 patients (16 ARPKD, 13 ADPK) imaged by at least two US examinations. We analysed the size and echogenicity of the kidneys, corticomedullary differentiation (CMD), the presence, location and size of cysts and any other anomaly that developed with time. In order to determine whether a relationship could be found between any of the US changes and the onset of the renal failure (based on a glomerular filtration rate < 50 ml/min per 1.73 m2), a Pearson exact chi-square test was calculated.

RESULTS

For ARPKD, renal size was above 4 standard deviations (SD) in 10 of 16 patients, but it remained stable during evolution (10/16). The kidneys appeared hyperechoic (16/16), without CMD in the majority (11/16) of patients. Changes in the appearance of CMD over time were observed in five patients. Small cysts (< 1 cm) were present at the time of diagnosis in seven patients, larger cysts (> 1 cm) in three. A diffuse microcystic pattern was observed in three patients. Diffuse hyperechoic foci developed in 14 patients--13 of whom had developed renal failure at the time of the examination or rapidly thereafter (statistical correlation P=0.0125). For ADPKD, renal size was between 0-2 SD in 7 of 13 patients and above 2 SD in the other 6. Renal echogenicity was normal in five, difficult to assess in five and the kidneys appeared hyperechoic without CMD in three patients. Cysts larger than 1 cm were present in 8 of 12 patients (> 3 cm in 5). In four patients, the cysts measured less than 1 cm. In the last child, the diagnosis had been made antenatally and the first cysts appeared at the age of 6 months. The size of the kidneys (13/13) and of the cysts (11/13) remained stable. No renal failure occurred.

CONCLUSIONS

ARPKD may manifest with various US patterns and there may be evolution in the appearances over time. Our study confirms a significant relationship between the development of diffuse hyperechoic foci and the onset of renal failure. In older children, ARPKD and ADPKD may closely resemble each other. Large (> 3 cm) cysts are the US hallmark for the diagnosis of ADPKD; furthermore, fewer US changes occur with time during childhood in ADPKD.

Intracranial aneurysms in a child with autosomal recessive polycystic kidney disease

Intracranial aneurysms (ICA) are a well-known feature of autosomal dominant polycystic kidney disease. There is only one report about ICA in an adult patient with autosomal recessive polycystic kidney disease (ARPKD). We observed a 2-year, 6-month old girl with ARPKD and multiple ICA. The family history is negative for kidney disease. The diagnosis of ARPKD was based on the typical findings in ultrasonography and computed tomography. Cystic ectasia of biliary ducts 6.3/4.8 cm in diameter was found in the liver. Arterial hypertension in a range of 140/100-170/120 mm Hg was registered. The child has polyuria, polydipsia and enuresis. Blood urea was 15 mmol/l, creatinine in a range of 120 to 75 micromol/l. One episode of vomiting, dizziness and lethargy was the reason for a brain magnetic resonance imaging. Multiple fusiform and saccular aneurysms in the branches of middle and posterior cerebral arteries were seen bilaterally. The girl is growing well without neurological symptoms during an observation period of 1.5 years. Blood pressure is well controlled with an ACE inhibitor (Enalapril 2.5 mg daily). It was concluded that ICA can be found in patients with ARPKD. Blood pressure control is essential to reduce the risk of intracranial hemorrhage.

Sonographic pattern of recessive polycystic kidney disease in young adults. Differences from the dominant form

BACKGROUND

To study the sonographic pattern of autosomal recessive polycystic kidney disease (ARPKD) in early adulthood in order to identify imaging criteria to diagnose this disease and to distinguish between recessive and autosomal dominant polycystic kidney disease (ADPKD) in that age group.

METHODS

An abdominal ultrasound was performed on four ARPKD subjects (with a mean age of 20.2) and on 33 ADPKD subjects in early adulthood (29 without renal failure with a mean age of 20.5, and four with renal failure with a mean age of 26.5). Linkage studies with ADPKD and ARPKD markers were compatible with the clinical diagnosis in all cases.

RESULTS

The renal sonographic features in ARPKD subjects included multiple small cysts in a normal-sized kidney, increased cortical echogenicity and loss of corticomedullary differentiation. In ADPKD subjects without renal failure, sonographic features included few or multiple cysts of different sizes, in normal-sized kidneys in 22 out of 29 patients (75.8%), normal cortical echogenicity and conserved corticomedullary differentiation, except in patients with nephromegaly. All ADPKD subjects with renal failure had nephromegaly and loss of corticomedullary differentiation. The hepatic sonographic features in ARPKD patients included portal fibrosis and in some cases Caroli's disease, while in ADPKD patients a normal hepatic echostructure was detected in all but one case, in addition to simple hepatic cysts in a few cases.

CONCLUSIONS

The evaluation of the sonographic features of the kidneys and those of the liver may help in the differential diagnosis between ARPKD and ADPKD in early adulthood.

[Lethal uropathies: prenatal diagnosis and feto-pathologic aspects]

Forty-three prenatal diagnoses of lethal urinary tract abnormalities were carried out during a five-year-period. The abnormalities were bilateral renal agenesis (56%), autosomal recessive polycystic kidney disease (16%), autosomal dominant polycystic kidney disease (14%), MECKEL-GRUBER syndrome and Prune-Belly syndrome (4%). The pregnancy was interrupted in thirty-five cases (81.4%).

Pulmonary hypertension in a child with juvenile-type autosomal recessive polycystic kidney disease

An 11 year-old girl, whose condition was diagnosed as juvenile-type autosomal recessive polycystic kidney disease (ARPKD) at five years of age, presented with chest pain and dyspnea that had developed suddenly two months previously. Two-dimensional echocardiography, Doppler study and cardiac catheterization confirmed pulmonary hypertension. The underlying mechanism of the diagnosis was not defined. Two and a half months after the onset of symptoms, the patient died of pulmonary hypertensive crisis. Careful regular checks of cardiopulmonary status using two-dimensional echocardiography and Doppler should be considered for the early detection of pulmonary hypertension even in an asymptomatic patient with juvenile-type ARPKD.

Sonographic findings in familial juvenile nephronophthisis-medullary cystic disease complex

PURPOSE

Familial juvenile nephronophthisis-medullary cystic disease complex (JN-MCD) is an autosomal inherited renal disease with insidious symptoms that ultimately progresses to renal failure. We describe the abnormal sonographic findings in JN-MCD at various stages of the disease in a Taiwanese family.

METHODS

We collected 8 cases in a family via 2 symptomatic index siblings. The affected members were 4 males and 4 females whose ages at diagnosis ranged from 1 to 39 years (mean, 16.8 years). Serial sonographic examinations were performed.

RESULTS

There were 4 abnormal findings: renal hyperechogenicity, poor corticomedullary differentiation, small kidney size, and corticomedullary cysts. Renal hyperechogenicity and poor corticomedullary differentiation were found in all cases. Renal cysts and reduced renal size sometimes appeared later, after the disease had progressed. Three cases had no visualized cysts.

CONCLUSIONS

Because abnormal renal sonographic findings can be seen long before the appearance of any clinical symptoms or signs, sonography is the best technique for diagnosing JN-MCD and for screening a patient's family.

Familial juvenile nephronophthisis. An ultrasonographic follow-up of seven patients

PURPOSE

To evaluate progressive US changes in the kidneys of patients with familial juvenile nephronophthisis (NPH), an autosomal recessive progressive kidney disease with polyuria, polydipsia, anemia and growth retardation.

MATERIAL AND METHODS

The data from 29 US investigations of 5 boys and 2 girls comprised findings relating to kidney size, echogenicity of the kidney parenchyma, visualization of the corticomedullary junction, and the parameters of renal cysts.

RESULTS

In the early stages of NPH, when the serum creatinine values were between 134 and 370 micromol/l, the corticomedullary differentiation was weak in 6 patients, the echogenicity of the kidney parenchyma was equal to or greater than that of the liver in 5 patients, and 6 patients had developed renal cysts. The findings became more intensive with the progression of NPH. The size of the kidneys remained normal in 4 patients.

CONCLUSION

Renal US reveals characteristic changes already in the early stages of NPH and should therefore be an important part of the diagnostics of NPH because no specific diagnostic test is as yet available.

The detection of murine autosomal recessive polycystic kidney disease using real-time ultrasound

Using currently available ultrasound equipment, 38 BPK and CPK mice were evaluated at 7 days of age for the presence of autosomal recessive polycystic kidney disease (ARPKD). The kidneys were less echogenic than adjacent soft tissues and measured between 5.1 and 6.3 mm from pole to pole in 32 unaffected mice and 1 with ARPKD. In 5 mice with ARPKD, the kidneys were similar in echogenicity to adjacent soft tissues and measured between 6.9 and 8.4 mm from pole to pole. Renal sonography is able to identify most mice with polycystic kidney disease prior to the development of abdominal enlargement and laboratory abnormalities, and shows promise for future applications in animal research.

[Meckel-Gruber syndrome]

The lethal Meckel-Gruber-Syndrome can be diagnosed prenatally during ultrasound screening between 16 and 20 weeks of pregnancy. Two case reports of Meckel-Gruber-Syndrome are given, which demonstrate the importance of a reliable ultrasound examination. The results supply the basis for an adequate counseling of the patient with the option of pregnancy termination in case of the lethal syndrome.

Intrahepatic bile duct dilatation and cholestasis in autosomal recessive polycystic kidney disease. Demonstration with hepatobiliary scintigraphy

Fifteen patients with the clinical and radiologic features of autosomal recessive polycystic kidney disease were investigated with radionuclide hepatobiliary scintigraphy. In nine patients (60%), cholestasis and intrahepatic bile duct dilatation were demonstrated. A 10th child had scintigraphic evidence of cholestasis, but the bile ducts were not dilated. The other five children has normal h hepatobiliary scans. The authors conclude that intrahepatic bile duct dilatation with cholestasis (Caroli's disease) is part of the clinical spectrum of autosomal recessive polycystic kidney disease and that hepatobiliary scintigraphy can be of value in determining the extent of hepatobiliary disease in this group of patients.

Prenatal sonographic diagnosis of autosomal recessive polycystic kidney disease (ARPKD) during the early second trimester

Autosomal recessive polycystic kidney disease (ARPKD) is a rare hereditary disease with a high neonatal mortality. Currently, prenatal diagnosis is possible only during the second half of pregnancy, when bilaterally enlarged, echogenic kidneys are visible by ultrasound. We describe a case in which a diagnosis of ARPKD was sought in the first half of pregnancy. High-resolution ultrasonography revealed echogenic, normal-sized kidneys at 15 + 4 weeks. Microsatellite DNA analysis of a chorionic villus sample, parental blood, and blood of an affected sibling showed that the fetus had the maternal haplotype and a recombination of the paternal haplotype. Thus, no distinction between homo- and heterozygosity for the ARPKD mutation in the fetus was possible. A further ultrasound examination at 19 + 4 weeks confirmed the previous results, indicating that the fetus was likely to be affected. After termination of the pregnancy, the diagnosis was confirmed on microscopic examination.

Autosomal recessive polycystic kidney disease: long-term sonographic findings in patients surviving the neonatal period

OBJECTIVE

We studied the sonographic findings and the changes in renal function seen on long-term follow-up of children who had the initial diagnosis of autosomal recessive polycystic kidney disease made in the neonatal period.

MATERIALS AND METHODS

The case records and sonograms of 14 children with biopsy evidence of autosomal recessive polycystic kidney disease were evaluated. Nine children who survived the neonatal period were followed up for a mean of 13 years (range, 5-19 years) after diagnosis and form the basis of this study. Serial changes in renal size, echogenicity, and function were assessed sonographically. The imaging findings were compared with those described in published reports.

RESULTS

The sonographic findings showed that five of the nine children had a decrease in renal size, and three had stable renal size over a minimum follow-up period of 5 years. Only one of the nine survivors showed progressive increase in renal size. All had increased cortical echogenicity and large kidneys. Three patients showed a subjective change in renal echogenicity over time. A change in the echogenic pattern to one that resembles autosomal dominant polycystic kidney disease was noted with no evidence of increase in size of the kidneys. None of the surviving children had renal stones or massively enlarged kidneys. The renal function of seven of the nine survivors has remained stable with creatinine clearance nearly normal (> 60 ml/min/1.73 m2), and there was no correlation between renal size and renal function.

CONCLUSION

In patients with autosomal recessive polycystic kidney disease who survive the neonatal period, kidney size as seen on sonograms does not continue to increase despite the patients' linear growth and maintained normal renal function. Rather, a decrease in kidney size and change in echogenicity occurs, producing a pattern that is similar to that seen on sonograms of patients with autosomal dominant polycystic kidney disease but without the marked increase in kidney size that occurs in that entity. This changing cystic pattern on follow-up sonograms may be the reason that previous descriptions of the sonographic findings in cases of autosomal recessive polycystic kidney disease have varied and why a decrease in size may not herald deteriorating renal function.

Molecular genetic diagnosis of autosomal dominant polycystic kidney disease in a newborn with bilateral cystic kidneys detected prenatally and multiple skeletal malformations

We report a case of an unusual prenatal presentation of polycystic kidneys associated with multiple skeletal limb defects, including polydactyly, syndactyly, bilateral agenesis of the tibia, and club foot. The ultrasonographic picture was consistent with a diagnosis of polycystic kidney disease, either the adult onset autosomal dominant type (ADPKD) or the early onset autosomal recessive form (ARPKD). However, there was a positive family history for ADPKD. Linkage analysis was performed in 10 family members, of whom four were affected, using six flanking DNA markers tightly linked to the PKD1 locus on chromosome 16p, and one marker linked to the putative PKD2 locus on chromosome 2p. Lod score determinations indicated that the affected gene in the family is most likely PKD1. The patient inherited the disease linked haplotype from his affected mother.

Renal calcifications in patients with autosomal recessive polycystic kidney disease: prevalence and cause

OBJECTIVE

We investigated the prevalence of renal calcifications in children with autosomal recessive polycystic kidney disease and studied the metabolic changes that could cause this complication.

SUBJECTS AND METHODS

Nine patients with known autosomal recessive polycystic kidney disease were examined with sonography and CT and screened for biochemical evidence of metabolic causes of nephrocalcinosis.

RESULTS

CT showed bilateral renal calcifications in seven of the nine patients. The two patients without renal calcifications were less than 1 year old. Four patients had only a few calcifications and three patients had many. The severity of the renal calcifications correlated with the degree of kidney failure. All patients with kidney failure were found to have urine acidification defects. Hypocitraturia was present in all patients.

CONCLUSION

Our results show that renal calcifications are common in older children with autosomal recessive polycystic kidney disease. Hypocitraturia and the urine acidification defect resulting from kidney failure are the leading factors in the pathogenesis of the calcifications.

Clues and pitfalls in the early prenatal diagnosis of 'late onset' infantile polycystic kidney

Infantile polycystic kidney disease (IPKD) is an autosomal recessive inherited disorder, IPKD has been previously diagnosed by us as early as the 14th week of gestation. 'Late onset' (third trimester) IPKD has been previously described by several authors. We present here a case of intrauterine detection of 'late onset' IPKD, suggesting that elongated hyperechogenic kidneys (with normal transverse and anteroposterior diameters) should be considered as an early sign of 'late onset' presenting IPKD.

Autosomal recessive (infantile) polycystic kidney disease demonstrated by Tc-99m DMSA renal imaging

A neonate with infantile polycystic kidney disease underwent Tc-99m DMSA imaging. The pattern of uptake in infantile polycystic disease is different from the multiple cystic lesions reported in the literature for adult polycystic kidney disease. The infantile pattern of uptake shows large kidneys with diffuse, symmetric localization of the radiopharmaceutical, which seems to be characteristic and may be pathognomonic of the disease process.

Prenatal diagnosis of autosomal recessive polycystic kidney disease by ultrasonography and magnetic resonance imaging

Autosomal recessive polycystic kidney disease is a relatively rare congenital disease affecting the kidneys and liver. We noticed the kidney abnormality at 22 weeks gestation and observed the patient till the delivery at 36 weeks of gestation. The ultrasonographic features consisted of bilaterally enlarged hyperechogenic kidneys, oligohydramnios, lack of distention and difficulty in identifying the fetal urinary bladder. The serial sonographic features of the kidneys changed as pregnancy progressed. The kidney cysts gradually changed in size, shape and renal texture, but the umbilical velocimetry and the kidney circumference/abdominal circumference ratio did not change. Magnetic resonance imaging also showed similar characteristic features as observed by ultrasonography.