Spectrum of glomerulocystic kidneys: a case report and review of the literature

Sporadic Form of Glomerulocystic Kidney Disease in a Child: A Case Report

Glomerulocystic kidney disease (GCKD) is a rare form of cystic renal disease. We report a four-week-old baby girl born to non-consanguineous parents; their antenatal third-trimester ultrasound showed severe oligohydramnios that required amnioinfusion. Post-natal ultrasound examination showed few tiny cysts (2-3mm) involving the cortices in bilateral kidneys. Kidney biopsy showed dilatation of Bowman's space and cystically dilated glomeruli, suggestive of GCKD. Whole exome sequencing revealed no pathogenic or likely pathogenic variant.

Glomerulocystic kidney: one hundred-year perspective

CONTEXT

Glomerular cysts, defined as Bowman space dilatation greater than 2 to 3 times normal size, are found in disorders of diverse etiology and with a spectrum of clinical manifestations. The term glomerulocystic kidney (GCK) refers to a kidney with greater than 5% cystic glomeruli. Although usually a disease of the young, GCK also occurs in adults.

OBJECTIVE

To assess the recent molecular genetics of GCK, review our files, revisit the literature, and perform in silico experiments.

DATA SOURCES

We retrieved 20 cases from our files and identified more than 230 cases published in the literature under several designations.

CONCLUSIONS

Although GCK is at least in part a variant of autosomal dominant or recessive polycystic kidney disease (PKD), linkage analysis has excluded PKD-associated gene mutations in many cases of GCK. A subtype of familial GCK, presenting with cystic kidneys, hyperuricemia, and isosthenuria is due to uromodullin mutations. In addition, the familial hypoplastic variant of GCK that is associated with diabetes is caused by mutations in TCF2, the gene encoding hepatocyte nuclear factor-1beta. The term GCK disease (GCKD) should be reserved for the latter molecularly recognized/inherited subtypes of GCK (not to include PKD). Review of our cases, the literature, and our in silico analysis of the overlapping genetic entities integrates established molecular-genetic functions into a proposed model of glomerulocystogenesis; a classification scheme emerged that (1) emphasizes the clinical significance of glomerular cysts, (2) provides a pertinent differential diagnosis, and (3) suggests screening for probable mutations.

Glomerulocystic disease: a severe form in a monozygous twin

One of monozygous twins presented with anuria from birth and was diagnosed on renal biopsy with glomerulocystic kidney disease. There was no associated congenital or hereditary disorder. The other twin was normal and ultrasonography of the renal tracts of both infants was normal. He was managed by peritoneal dialysis. As renal transplantation was not available, the parents discharged him without further treatment.

Cystic kidney disease presenting in infancy

AIM

The clinical, histological and imaging findings of 12 children with ultrasound features of severe renal cystic disease presenting in the first year of life were reviewed.

METHODS AND RESULTS

Two children had cystic dysplasia and four had autosomal dominant polycystic disease. Two had a malformation syndrome, one a variant of Meckel syndrome and the other Bardet Biedl syndrome. One had autosomal recessive polycystic disease and in three there was no final diagnosis. Intravenous urography gave non-specific information. In six cases clinical findings combined with imaging established a diagnosis. Diagnosis was established by biopsy in two and gave supportive evidence in one. Outlook for renal function is variable. One child has had a transplant and one is on dialysis awaiting a transplant. Three have a degree of renal failure and one has died. Six have normal renal function. Renal cystic disease is the common pathway for a heterogeneous group of disorders as shown in these children.

CONCLUSION

It is emphasized that a specific diagnosis could not be made from the renal sonographic appearances alone, nor could any prognostic implications for renal function be made. Contrast retention on intravenous urography was also insufficiently specific to be of value. Ultrasound of the parents was the most useful imaging procedure and should be done in all cases.

Ivemark's renal-hepatic-pancreatic dysplasia: analytic approach to a perinatal autopsy

A case of Ivemark's renal-hepatic dysplasia syndrome is presented. The findings are suggestive of a ductal obstructive process anatomically located at the junction of ducts with the parenchyma. The differential diagnosis includes Meckel syndrome, short rib polydactyly syndromes, and glutaric aciduria type 2. The molecular basis for this syndrome remains unknown.

Role of Mxi1 in ageing organ systems and the regulation of normal and neoplastic growth

Mxi1 belongs to the Mad (Mxi1) family of proteins, which function as potent antagonists of Myc oncoproteins. This antagonism relates partly to their ability to compete with Myc for the protein Max and for consensus DNA binding sites and to recruit transcriptional co-repressors. Mad(Mxi1) proteins have been suggested to be essential in cellular growth control and/or in the induction and maintenance of the differentiated state. Consistent with these roles, mxi1 may be the tumour-suppressor gene that resides at region 24-26 of the long arm of chromosome 10. This region is a cancer hotspot, and mutations here may be involved in several cancers, including prostate adenocarcinoma. Here we show that mice lacking Mxi1 exhibit progressive, multisystem abnormalities. These mice also show increased susceptibility to tumorigenesis either following carcinogen treatment or when also deficient in Ink4a. This cancer-prone phenotype may correlate with the enhanced ability of several mxi1-deficient cell types, including prostatic epithelium, to proliferate. Our results show that Mxi1 is involved in the homeostasis of differentiated organ systems, acts as a tumour suppressor in vivo, and engages the Myc network in a functionally relevant manner.