Renal-hepatic-pancreatic dysplasia: an autosomal recessive malformation

Renal-hepatic-pancreatic dysplasia-1 with a novel NPHP3 genotype: a case report and review of the literature

BACKGROUND

Renal-hepatic-pancreatic dysplasia type 1 (RHPD1) is a rare sporadic and autosomal recessive disorder with unknown incidence. RHPD1 is caused by biallelic pathogenic variants in NPHP3, which encode nephrocystin, an important component of the ciliary protein complex.

CASE PRESENTATION

In this case report, we describe a male newborn who was confirmed by ultrasound to have renal enlargement with multiple cysts, pancreatic enlargement with cysts, and increased liver echogenicity, leading to the clinical diagnosis of RHPD. In addition, a compound heterozygous pathogenic variant, namely, NPHP3 c.1761G > A (p. W587*) and the c.69delC (p. Gly24Ala24*11) variant, was detected by WES. The patient was clinically and genetically diagnosed with RHPD1. At 34 h of life, the infant died of respiratory insufficiency.

CONCLUSION

This is the first published case of RHPD1 in China. This study broadens the known range of RHPD1 due to NPHP3 pathogenic variants.

Failure to Thrive, Jaundice, and Polyuria in Early Infancy: Common Presentation with an Uncommon Lethal Etiology

A 5-month-old female infant from a consanguineous Indian Muslim family presented with polyuria, polydipsia, failure to thrive, impaired renal function, and neonatal hepatitis of unknown cause at 1 month of age. Clinical exome testing revealed renal-hepatic-pancreatic dysplasia caused by homozygous c. 1985 + 5G > A pathogenic variations in NPHP3 . Our case illustrates delay in confirmatory diagnosis of such rare disorders in our region due to the lack of suspicion and unawareness of the availability of genetic testing even when there are no cost constraints.

Placental mesenchymal dysplasia and fetal renal-hepatic-pancreatic dysplasia: androgenetic-biparental mosaicism and pathogenesis of an autosomal recessive disorder

Androgenetic-biparental mosaicism (ABM) denotes an embryo in which a subset of cells contains a diploid chromosomal complement derived entirely from the father. Such embryos have a high incidence of placental mesenchymal dysplasia (PMD) and paternal imprinting disorders because the androgenetic cells have pangenomic paternal uniparental disomy. Uniparental disomy also poses a theoretical risk for paternally transmitted autosomal recessive disorders, if both chromosomes of each autosomal pair are identical (isodisomy). We present the 1st example of a recessive disorder, renal-hepatic-pancreatic dysplasia, in a pregnancy complicated by PMD and ABM. Androgenetic-biparental mosaicism was demonstrated in fetal DNA, extracted from multiple organs, by quantitative polymerase chain reaction-based methods that detected allelic imbalances at the differentially methylated SNRPN locus (chromosome 15); polymorphic short tandem repeat microsatellite markers located on chromosomes 4, 7, 8, 13, 18, and 21; and single nucleotide polymorphisms on chromosomes 1 and 19. Laser capture microdissection was performed to isolate specific placental and renal cell populations and document selective enrichment of androgenetic cells in the stroma of PMD and the epithelium of renal cysts. Mutational analysis of coding sequences did not reveal any mutations in NPHP3, a ciliopathy gene implicated in some cases of renal-hepatic-pancreatic dysplasia. Nonetheless, the fetal phenotype and laser capture data support the model of a paternally transmitted autosomal recessive disorder, which occurred because of ABM.

Goldston syndrome in a fetus: case report and literature review

We present a case of the Goldston syndrome which is the association of polycystic kidneys with Dandy-Walker malformation. The diagnosis was made by ultrasound in twenty second week of gestation. Obstetric ultrasound and fetal MRI studies showed hydrocephalus, agenesis of the cerebellar hemispheres, vermian hypoplasia, cystic dilatation of the 4(th) ventricle, enlargement of the posterior fossa, abdominal distension, and oligohydramnios.. The kidneys were symmetrically enlarged and multicystic. To our knowledge this is the third reported case of Goldston syndrome which was diagnosed during intrauterine life.

Liver and kidney disease in ciliopathies

Hepatorenal fibrocystic diseases (HRFCDs) are among the most common inherited human disorders. The discovery that proteins defective in the autosomal dominant and recessive polycystic kidney diseases (ADPKD and ARPKD) localize to the primary cilia and the recognition of the role these organelles play in the pathogenesis of HRFCDs led to the term "ciliopathies." While ADPKD and ARPKD are the most common ciliopathies associated with both liver and kidney disease, variable degrees of renal and/or hepatic involvement occur in many other ciliopathies, including Joubert, Bardet-Biedl, Meckel-Gruber, and oral-facial-digital syndromes. The ductal plate malformation (DPM), a developmental abnormality of the portobiliary system, is the basis of the liver disease in ciliopathies that manifest congenital hepatic fibrosis (CHF), Caroli syndrome (CS), and polycystic liver disease (PLD). Hepatocellular function remains relatively preserved in ciliopathy-associated liver diseases. The major morbidity associated with CHF is portal hypertension (PH), often leading to esophageal varices and hypersplenism. In addition, CD predisposes to recurrent cholangitis. PLD is not typically associated with PH, but may result in complications due to mass effects. The kidney pathology in ciliopathies ranges from non-functional cystic dysplastic kidneys to an isolated urinary concentration defect; the disorders contributing to this pathology, in addition to ADPKD and ARPKD, include nephronophithisis (NPHP), glomerulocystic kidney disease and medullary sponge kidneys. Decreased urinary concentration ability, resulting in polyuria and polydypsia, is the first and most common renal symptom in ciliopathies. While the majority of ADPKD, ARPKD, and NPHP patients require renal transplantation, the frequency and rate of progression to renal failure varies considerably in other ciliopathies. This review focuses on the kidney and liver disease found in the different ciliopathies.

Immunohistochemical study of the phenotypic change of the mesenchymal cells during portal tract maturation in normal and fibrous (ductal plate malformation) fetal liver

Background

In adult liver, the mesenchymal cells, portal fibroblasts and vascular smooth muscle cells can transdifferentiate into myofibroblasts, and are involved in portal fibrosis. Differential expression of markers, such as alpha-smooth muscle actin (ASMA), h-caldesmon and cellular retinol-binding protein-1 allows their phenotypic discrimination. The aim of our study was to explore the phenotypic evolution of the mesenchymal cells during fetal development in normal liver and in liver with portal fibrosis secondary to ductal plate malformation in a series of Meckel-Gruber syndrome, autosomal recessive polycystic kidney disease and Ivemark's syndrome.

Results

At the early steps of the portal tract maturation, portal mesenchymal cells expressed only ASMA. During the maturation process, these cells were found condensed around the biliary and vascular structures. At the end of maturation process, only cells around vessels expressed ASMA and cells of the artery tunica media also expressed h-caldesmon. In contrast, ASMA positive cells persisted around the abnormal biliary ducts in fibrous livers.

Conclusion

As in adult liver, there is a phenotypic heterogeneity of the mesenchymal cells during fetal liver development. During portal tract maturation, myofibroblastic cells disappear in normal development but persist in fibrosis following ductal plate malformation.

Differential diagnosis of fetal hyperechogenic cystic kidneys unrelated to renal tract anomalies: A multicenter study

OBJECTIVES

To identify important factors in the differential diagnosis of renal cysts associated with hyperechogenic kidneys.

METHODS

This was a retrospective multicenter study. We identified 93 fetuses presenting between 1990 and 2002 with hyperechogenic kidneys and which had a diagnosis of nephropathy confirmed later. We analyzed retrospectively the prenatal ultrasound findings of those fetuses which were found sonographically to have renal cysts.

RESULTS

Of the 93 fetuses presenting with hyperechogenic kidneys and with a later diagnosis of nephropathy, there were 28 with autosomal dominant polycystic kidney disease (ADPKD), 31 with autosomal recessive polycystic kidney disease (ARPKD), 11 with Bardet-Biedl syndrome, nine with Meckel-Gruber syndrome, six with Ivemark II syndrome, one with Jarcho-Levin syndrome, one with Beemer syndrome and one with Meckel-like syndrome. One third of the fetuses (30/93) had renal cysts. Cystic characteristics (size, location, number) were not very useful for diagnosis; more useful was diagnosis of an associated malformation. Three (11%) of the fetuses with ADPKD had cysts, as did nine (29%) of those with ARPKD, three (27%) of those with Bardet-Biedl syndrome, all (100%) of those with Meckel-Gruber syndrome, three (50%) of those with Ivemark II syndrome, and each of the three cases with other syndromes (Jarcho-Levin, Beemer and Meckel-like syndromes). None of the cases with trisomy 13 had cysts. There were no associated malformations in the 12 cases with renal cysts and polycystic kidney disease; the other 18 cases with renal cysts were associated with malformations that were often specific, such as polydactyly in Bardet-Biedl and Beemer syndromes, occipital defect and Dandy-Walker malformation in Meckel-Gruber or Meckel-Gruber-like syndromes, and thoracic and/or vertebral abnormalities in Jarcho-Levin and Beemer syndromes.

CONCLUSION

Renal cysts associated with hyperechogenic kidneys are not rare. The clue to diagnosis is the demonstration of an associated malformation. If no malformation is found, the main diagnosis remains polycystic kidney disease, i.e. ARPKD or ADPKD.

Biliary tract malformations

The biliary tree extends from the canals of Hering at the margin of the most peripheral portal tracts to the ampulla of Vater. Malformations occur at every level of this structure. Phenotypic features dominate present understanding of these malformations and of the disorders with which they are associated. Classifications of disease will likely shift from a phenotypic basis to a genotypic basis as genes implicated in biliary tree development and function are identified. Involvement of such genes in biliary tree disorders now considered inflammatory, such as extrahepatic biliary atresia, awaits study. The concept of "feeble cholangiocytes" postnatally susceptible to the effects of "toxic bile" is presented.

Prenatal sonographic appearance of congenital bile duct dilatation associated with renal-hepatic-pancreatic dysplasia

We report the prenatal sonographic features of congenital bile duct dilatation associated with renal-hepatic-pancreatic dysplasia. The condition was seen at 22 weeks of gestation and led to termination of pregnancy. This is the first description of congenital bile duct dilatation using prenatal sonography. It is also the first report of a case in which the features of dysplasia were evident in all three of the organs which may be affected, the kidneys, liver and pancreas.

Two new cases of Cumming syndrome confirming autosomal recessive inheritance

We report on two stillborn sisters with generalized hydrops, campomelia, cervical lymphocele, and polycystic dysplasia of kidney, liver, and pancreas. This syndrome conforms to that first described by Cumming et al. [Am. J. Med. Genet. 25:783-790, 1986]. This observation provides additional support for the notion that this syndrome has an autosomal recessive pattern of inheritance.

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.

Anencephaly-associated aganglionosis

Autopsies of 12 consecutively born infants with anencephaly showed varying degrees of aganglionosis and lateralization defects in four of them. This seemingly regular occurrence of these three defects together suggests that they are caused by an aberration of blastogenesis that results in a polytopic field defect.