Pre-natal diagnosis of adult polycystic kidney disease

Neonatal polycystic kidney disease: a novel variant

Polycystic kidney disease (PKD) is a condition typified by multiple renal cysts and renal enlargement. Classification is usually determined by mode of inheritance-autosomal dominant PKD (ADPKD) or autosomal recessive PKD (ARPKD). ARPKD frequently presents in fetal life, but here we report a rare case of a family with two siblings diagnosed with ADPKD manifesting in utero with novel genetic findings. During the first pregnancy, enlarged cystic kidneys were noted at the gestational age (GA) of 18 weeks, which became progressively larger and anyhdramnios ensued by GA of 25 weeks. The couple opted to terminate the pregnancy. The second pregnancy similarly presented with bilateral enlarged cystic kidneys, but amniotic fluid remained normal throughout and she delivered at GA of 36 weeks. Genetic testing revealed the fetus to be heterozygous in AD PKD1, which is known to cause ADPKD and heterozygous for a hypomorphic allele for ADPKD of uncertain significance. The fetus was also found to be heterozygous in the AR PKHD1 gene with a variant not previously described in the literature. Where fetal features consistent with ARPKD are identified in the setting of familial ADPKD, this fetal manifestation of ADPKD, resulting from combined variants in the PKD1 gene, should be considered.

Prognosis of autosomal dominant polycystic kidney disease diagnosed in utero or at birth

The use of prenatal ultrasonography has resulted in increased numbers of fetuses being diagnosed with autosomal dominant polycystic kidney disease (ADPKD), but the long-term prognosis is still not well-known. Between 1981 and 2006 we followed 26 consecutive children with enlarged hyperechoic kidneys detected between the 12th week of pregnancy and the first day of life (Day 1) as well as one affected parent. Three other fetuses were excluded following the termination of the pregnancy. The mother was the transmitting parent in 16 of the 26 children (ns, p=0.1). Clinical features that presented during follow-up were oligoamnios (5/26), neonatal pneumothorax (3/26), pyelonephritis (5/26), gross hematuria (2/26), hypertension (5/26), proteinuria (2/26) and chronic renal insufficiency (CRI) (2/26). At the last follow-up (mean duration of follow-up: 76 months; range: 0.5-262 months), 19 children (mean age: 5.5 years) were asymptomatic, five (mean age: 8.5 years) had hypertension, two (mean age: 9.7 years) had proteinuria and two (mean age: 19 years) had CRI. Children presenting enlarged kidneys postnatally tended to have more clinical manifestations than their counterparts who did not. Of 25 siblings of the patients, seven had renal cysts; these were detected during childhood in five siblings and in utero in two siblings. In conclusion, prognosis is favourable in most children with prenatal ADPKD, at least during childhood. The sex of the transmitting parent is not a risk factor of prenatal ADPKD. A high proportion of siblings develop early renal cysts. Abnormalities visualized by ultrasonography appear to be associated to more clinical manifestations.

A 10 year audit of antenatal ultrasound detection of renal disease

During a 10 year period, a renal tract anomaly was suspected on antenatal ultrasound in 125 fetuses, an incidence of five per 1000 births. 107 live births resulted. Three of six babies with renal failure were stented antenatally. A chromosome anomaly was present in three fetuses (2.4%). No live birth resulted in 14 pregnancies associated with oligohydramnios and no visible fetal bladder. Of those with renal agenesis or bilateral cystic dysplasia, one had a chromosome defect and a further four had extrarenal anomalies. Nine fetuses demonstrated isolated parenchymal hyperechogenicity and trisomy occurred in two of four with bilateral change in enlarged kidneys. All 14 babies with unilateral renal cysts had normal renal function postnatally, but only three of the cystic kidneys showed function. Antenatally, typical multicystic change was seen in 10, and smaller unevenly distributed cysts in four kidneys. Contralateral parenchymal echogenicity and/or pelvicalyceal distension indicating dysplasia was identified in four fetuses. Of 78 fetuses with isolated pelvic with or without calyceal distension the outcome was completely normal in 59% with unilateral, and in 48% with bilateral changes. One baby with unilateral and three with bilateral changes required dialysis or renal transplantation. One of four babies with antenatal ureteric distension had renal failure. Only one of six fetuses with bladder distension is alive in renal failure after in utero stenting.

Prenatal ultrasonographic findings of dominant polycystic kidney disease and postnatal renal evolution

Autosomal dominant polycystic kidney disease (ADPKD) is a relatively common genetic disorder, and its prenatal diagnosis has been reported with increasing frequency. Nevertheless, no data are available on the significance of prenatal ultrasound (US) patterns in predicting postnatal renal function and outcome. We report on one case of ADPKD diagnosed prenatally by US, and on two cases diagnosed immediately after birth, with different prenatal US and renal outcomes. Data on prenatal US findings and postnatal renal evolution are scanty and largely incomplete. Apparently, none of the prenatal findings are consistently different in cases with and without normal postnatal renal function and blood pressure. More complete information on prenatal US findings and postnatal renal evolution is urgently needed.

Autosomal dominant polycystic kidney disease in the fetus

We report on 3 cases with a fetal presentation of autosomal dominant polycystic kidney disease (ADPKD), which illustrate the variable expression of ADPKD during fetal life. Fetus 1 was diagnosed at 20 weeks of gestation by ultrasonography; a molecular prenatal diagnosis was performed at 10 weeks on fetus 2, a sib of fetus 1; and ADPKD was an incidental finding in fetus 3 who was aborted at 16 weeks for anencephaly. All pregnancies were terminated and pathologic studies of the fetal kidneys were performed. From these cases and a review of the literature, we draw the following conclusions: (1) so far, all fetal ADPKD kidneys that have been histologically studied have shown cystic dilatations; 28/32 of these fetuses had ultrasonographic manifestations of the disease and/or had sibs with an early-onset form of it; (2) these cysts can be found in newly formed nephrons (fetus 2), predominantly in the more mature nephrons of the deep cortex (fetus 1) or more sparsely distributed in the cortex (fetus 3); these different patterns may reflect different rates of progression of the disease; (3) in contrast to the histologic findings in adult kidneys, glomeruli seem to be predominantly affected in fetal ADPKD; (4) severe fetal expression of ADPKD seems to cluster in some families; and (5) so far, all DNA analyses performed in families with subjects presenting during the fetal or neonatal period have been consistent with linkage to the PKD1 locus.

Glomerulocystic kidney disease--nosological considerations

Glomerulocystic kidneys can be categorized into three major groups: (1) glomerulocystic kidney disease, comprising nonsyndromal heritable and sporadic forms of severely cystic kidneys in children and adults, (2) glomerulocystic kidneys in heritable malformation syndromes, and (3) glomerular cysts in dysplastic kidneys. The first category includes diffusely glomerulocystic kidneys in newborns and young children, many of whom have family histories positive for classical polycystic kidney disease. No differences between familial and sporadic cases have been identified, apart from the family histories. The sporadic cases are conceivably new mutations of the same disease. The first category also includes sporadic and familial disease in older children and adults. The inheritance in adult familial disease, as in childhood familial disease, has been dominant. An apparently distinct entity is hypoplastic glomerulocystic kidney disease, a dominant reported in only a few families. These kidneys, apart from being glomerulocystic, are small, and imaging studies show abnormal pyelocaliceal anatomy. The second category includes glomerulocystic kidneys as major components of heritable syndromes such as tuberous sclerosis, orofaciodigital syndrome, brachymesomelia-renal syndrome, trisomy 13, and the short rib-polydactyly syndromes. The category also includes glomerular cysts in several syndromes, namely Jeune syndrome and familial juvenile nephronophthisis, better known for chronic progressive tubulointerstitial disease. Glomerular cysts occur as a minor component, i.e., scattered cortical cysts, in several other syndromes, among them Zellweger's, in which the cysts are typically present and are usually inconsequential, only occasionally serious enough to affect renal function. In all of these syndromes, the cysts are inconsistently expressed.(ABSTRACT TRUNCATED AT 250 WORDS)