Congenital nephrotic syndrome: prenatal diagnosis and genetic counselling by estimation of aminotic-fluid and maternal serum alpha-fetoprotein

Usefulness of Early Genetic Diagnosis for Twins With a Family History of Congenital Nephrotic Syndrome

We reported a dichorionic diamniotic placental twin (DD twin) with a family history of a congenital nephrotic syndrome of the Finnish type (CNF), of which the parent had heterozygous for the NPHS1 gene mutation. The DD twin was born at 36 weeks gestation, and their fused placenta weighed 1,340 g. Although the first-born child had heavy proteinuria and hypoalbuminemia and needed daily albumin replacement to manage severe edema, the second had only mild proteinuria after birth. Genetic testing performed 28 days after birth detected homozygous for the NPHS1 gene mutation in only the first-born child but not in the second, which resulted in performing invasive left nephrectomy and peritoneal dialysis (PD) to manage edema in the first. For DD twins with a family history of CNF, prenatal diagnosis of CNF may be difficult. Therefore, close postnatal clinical observation and early genetic testing are essential for the diagnosis of CNF.

Pathology of Podocytopathies Causing Nephrotic Syndrome in Children

Nephrotic syndrome (NS) in children includes a diverse group of diseases that range from genetic diseases without any immunological defects to causes that are primarily due to immunological effects. Recent advances in molecular and genomic studies have resulted in a plethora of genetic defects that have been localized to the podocyte, the basic structure that is instrumental in normal filtration process. Although the disease can manifest from birth and into adulthood, the primary focus of this review would be to describe the novel genes and pathology of primary podocyte defects that cause NS in children. This review will restrict itself to the pathology of congenital NS, minimal change disease (MCD), and its variants and focal segmental glomerulosclerosis (FSGS). The two major types of congenital NS are Finnish type characterized by dilated sausage shaped tubules morphologically and diffuse mesangial sclerosis characterized by glomerulosclerosis. MCD has usually normal appearing biopsy features on light microscopy and needs electron microscopy for diagnosis, whereas FSGS in contrast has classic segmental sclerosing lesions identified in different portions of the glomeruli and tubular atrophy. This review summarizes the pathological characteristics of these conditions and also delves into the various genetic defects that have been described as the cause of these primary podocytopathies. Other secondary causes of NS in children, such as membranoproliferative and membranous glomerulonephritis, will not be covered in this review.

Amniotic fluid glial fibrillary acidic protein (AF-GFAP), a biomarker of open neural tube defects

OBJECTIVE

Neural tube defects (NTDs) are usually identified by ultrasonography and confirmed by alpha-fetoprotein (AFP) assay and acetylcholinesterase (AchE) electrophoresis in amniotic fluid. Yet, both of these biomarkers can be found positive in other etiologies. Here, amniotic fluid glial fibrillary acidic protein (AF-GFAP), which was identified by a proteomic study, is shown to be a useful biomarker for NTD diagnosis.

METHOD

Amniotic fluid glial fibrillary acidic protein was measured by an ELISA assay in 138 cases of NTDs. Seventy samples from normal pregnancies used as controls and 27 samples giving false positive or false negative results either for AchE or AFP and corresponding to fetal death (n = 8), gastroschisis (n = 8), and unexplained etiologies (n = 11) were also tested.

RESULTS

Whatever the gestational age, GFAP was below 0.2 ng/mL in control samples, whereas 99.1% of open NTDs (29/29 in the anterior NTD group and 80/81 in the spina bifida group) were above this threshold. Closed NTDs were all negative (28/28). None of the other samples tested were positive, except in case of fetal death (8/8).

CONCLUSIONS

Amniotic fluid glial fibrillary acidic protein is a sensitive biomarker for open NTD diagnosis with a good negative predictive value for closed NTD. Compared with AFP and AchE, our results indicate that AF-GFAP alone is more efficient than this classical association.

Syndromes néphrotiques congénitaux et infantiles

Congenital nephrotic syndrome is present at birth or appears during the first three months of life and infantile nephrotic syndrome during the first year. Finnish type congenital nephrotic syndrome is an autosomal recessive disease. Nephrotic syndrome is present at birth, severe and does not respond to therapy. Infectious and nutritional complications are frequent. Renal function deteriorates necessitating a dialysis-transplantation program. Between age five and eight. The disease does not recur after transplantation. Diffuse mesangial sclerosis is the second cause of congenital and infantile nephrotic syndrome. It may be isolated or part of a Denys-Drash syndrome (association of the nephropathy with male pseudohermaphroditism and Wilm's tumor). Nephrotic syndrome is resistant to therapy. Renal failure develops in early childhood. Therapy is aimed to prevent oedema, denutrition, infections and thrombosis. Proteinuria does not recur after renal transplantation. Other causes are less frequent.

Prenatal diagnosis of congenital nephrosis by in utero kidney biopsy

The diagnosis of congenital nephrosis is difficult during the antepartum period. The combination of an elevated amniotic fluid alpha-fetoprotein, a negative acetylcholinesterase, and a negative ultrasound examination is highly indicative of congenital nephrosis; however, these findings can also be associated with a normal gestation. This is the first report of pathologic confirmation of congenital nephrosis from an in utero fetal kidney biopsy.

Nephrin localizes at the podocyte filtration slit area and is characteristically spliced in the human kidney

Defects in the newly reported gene NPHS1 in chromosome 19 cause the massive proteinuria of Finnish type congenital nephrotic syndrome (CNF). Together with its gene product, nephrin, NPHS1 is providing new understanding of the pathophysiological mechanisms of glomerular filtration. Here we show the characteristic splicing of NPHS1 mRNA in the normal and CNF kidneys and localize nephrin exclusively in the glomerulus and to the filtration slit area by light and immunoelectron microscopy. These results indicate that nephrin is a new protein of the interpodocyte filtration slit area with a profound role in the pathophysiology of the filtration barrier.

Improved prognosis for congenital nephrotic syndrome of the Finnish type in Irish families

Congenital nephrotic syndrome of the Finnish type is a rare autosomal recessive disease with a high infant mortality without aggressive treatment. The biochemical basis of the disease is not understood fully but the disease locus has been mapped recently to chromosome 19q12-q13.1 in Finnish families. This paper describes the clinical features and outcome of 20 patients in Ireland with congenital nephrotic syndrome of the Finnish type who have presented since 1980. Before 1987, all infants died by the age of 3 years. After the introduction of daily intravenous albumin infusion, nutritional support, elective bilateral nephrectomy, and renal transplantation, mortality in the past decade has fallen to 30%, with no deaths in the past five years. Genetic linkage analysis was performed in six families in whom DNA was available and the locus responsible was mapped to the same region on chromosome 19 as in Finnish families, suggesting that Irish families share the same disease locus.

Prediction of pre-eclampsia with maternal mid-trimester total renin, inhibin A, AFP and free beta-hCG levels

We wanted to study if maternal serum mid-trimester total renin, inhibin A, AFP or free beta-hCG levels predict the development of pre-eclampsia. Maternal serum alpha-fetoprotein (AFP) and human chorion gonadotrophin (beta-hCG) were evaluated in the screening programme for Down syndrome in 4356 patients prospectively. Data on pregnancy outcome were available in 1242 women. Pregnancy-induced hypertension (PIH) developed in 69 women, 282 women with uneventful pregnancy outcome were selected for controls. Serum total renin and inhibin A levels were measured retrospectively in the trisomy screening samples of 69 and 30 patients who later developed PIH, and in 282 and 7 patients, respectively, who had an uneventful pregnancy outcome. No significant differences were found in the levels of maternal mid-trimester serum total renin, inhibin A or free beta-hCG levels between PIH and healthy women. The multiples of the median (MoM) of AFP values were significantly higher in the subgroup of patients who later developed severe pre-eclampsia than in patients with mild pre-eclampsia or gestational hypertension and healthy pregnant women. Maternal mid-trimester serum levels of total renin, inhibin A and free beta-hCG are not predictive for development of PIH. High mid-trimester serum AFP values may help in the prediction of severe pre-eclampsia.

Structure of the gene for congenital nephrotic syndrome of the finnish type (NPHS1) and characterization of mutations

Congenital nephrotic syndrome of the Finnish type (NPHS1) is an autosomal recessive disorder that is caused by mutations in the recently discovered nephrin gene, NPHS1 (AF035835). The disease, which belongs to the Finnish disease heritage, exists predominantly in Finland, but many cases have been observed elsewhere in Europe and North America. The nephrin gene consists of 29 exons spanning 26 kb in the chromosomal region 19q13.1. In the present study, the genomic structure of the nephrin gene was analyzed, and 35 NPHS1 patients were screened for the presence of mutations in the gene. A total of 32 novel mutations, including deletions; insertions; nonsense, missense, and splicing mutations; and two common polymorphisms were found. Only two Swedish and four Finnish patients had the typical Finnish mutations: a 2-bp deletion in exon 2 (Finmajor) or a nonsense mutation in exon 26 (Finminor). In seven cases, no mutations were found in the coding region of the NPHS1 gene or in the immediate 5'-flanking region. These patients may have mutations elsewhere in the promoter, in intron areas, or in a gene encoding another protein that interacts with nephrin.

Hereditary persistence of alpha-fetoprotein. Case report and review of the literature

Persistently elevated alpha-fetoprotein (AFP) levels of 24 to 30 micrograms/ml (normal < 10 micrograms/ml) were found in a 38-year-old healthy man. Subsequently, AFP was found to be elevated in another five out of 13 family members within three generations. The pedigree is consistent with an autosomal dominant inheritance pattern. No discernible disease and no functional abnormality appears to be associated with this clinically benign disorder which has been recorded in the literature on four occasions to date. The reported AFP levels in these other cases ranged from 18 to 198 micrograms/ml. Physiologically, AFP is mainly produced in the liver and the yolk sac of human fetuses more than four weeks old, with peak values of up to 4 mg/ml at 12 to 16 weeks of gestation. After birth, AFP levels usually fall, within eight to 12 months, to a very low concentration of < 10 micrograms/ml and persist at low levels throughout life. However, AFP levels can rise above normal in both children and adults in distinct conditions and diseases which will be discussed. Hereditary persistence of alpha-fetoprotein (HPAFP) should be considered in both children and adults with unexplained and persistent elevation of AFP e.g., those screened for hepatocellular carcinoma or diagnosed for germ cell tumor. It should also be recognized in AFP screening for neural tube defects or Down's syndrome during pregnancy. Hereditary persistence of AFP can be easily confirmed by analyzing AFP levels in family members.

Improved prenatal diagnosis of the congenital nephrotic syndrome of the Finnish type based on DNA analysis

Haplotype analysis and alpha-fetoprotein quantitation comprise a prenatal diagnosis of congenital nephrosis. Congenital nephrotic syndrome of the Finnish type (CNF) is an autosomal recessive disease characterized by massive proteinuria and nephrotic syndrome from birth. Prenatal diagnosis of CNF has previously been based on the quantitation of alpha-fetoprotein (AFP) in the amniotic fluid and maternal serum, but an increased AFP is not specific for the disease. We have recently localized the CNF gene to the chromosome 19q13.1 region and observed a strong linkage disequilibrium to the genetic markers D19S610, D19S608, D19S224 and D19S220 in this chromosomal area. Four main CNF-haplotypes have been observed in Finnish kindreds. In the present study, linkage and haplotype analyses have been applied to prenatal diagnosis of six families with a history of CNF. The results diminish the risk of false positive diagnosis and abortions of healthy fetuses in families at risk.

Uterine malformation: a cause of elevated maternal serum alpha-fetoprotein concentrations

This study was undertaken to investigate the association between uterine anomalies and unexplained elevated maternal serum alpha-fetoprotein (MSAFP) concentrations during the early second trimester. The incidence of uterine anomalies was retrospectively evaluated among pregnant women showing elevated (> 2.5 multiples of the median) mid-trimester maternal serum AFP (N = 312) concentrations in otherwise normal singleton pregnancies and then compared with that amongst patients from the same clinic showing normal serum AFP results (N = 28410). Basic clinical data of the study group were also analysed. The rate of diagnosed developmental uterine malformations in patients showing elevated MSAFP levels was 1 in 31, whereas the rate in the control group was 1 in 710 (3.2 per cent vs. 0.14 per cent). The relative risk was 22.1 [95 per cent confidence interval (CI) 11.1-43.7]. Amniotic fluid (AF) concentrations of AFP were normal in the study group. Our preliminary observations suggest that elevated MSAFP in the second trimester may in some cases be explained as being solely a result of uterine anomaly. The fetal to maternal transfer of AFP occurs by a transplacental, not a transamniotic, route, since AFAFP concentrations were normal. Consequently, obstetricians taking care of these patients should take this possibility into account.

Elevated maternal serum and amniotic fluid alpha-fetoprotein levels in the Denys-Drash syndrome

We report the findings in a child with the Denys-Drash syndrome presenting prenatally with a diaphragmatic hernia, male pseudohermaphroditism, and elevated alpha-fetoprotein levels i amniotic fluid and in maternal serum.

Congenital nephrotic syndrome of the Finnish type: linkage to the locus in a non-Finnish population

Congenital nephrotic syndrome of the Finnish type (CNF) is inherited as an autosomal recessive trait. The biochemical basis of the disease is unknown, although a lesion in the glomerular basement membrane is strongly suggested. Recently, the CNF locus was assigned to chromosome 19q12-q13.1 on the basis of linkage analysis in Finnish families. The high incidence of the disease in Finland, as well as the demonstration of linkage disequilibrium in the Finnish study, strongly suggests a founder effect based on a common ancient mutation in this population. We confirm linkage of the CNF locus to the same chromosomal region in seven non-Finnish CNF families without evidence of linkage disequilibrium. Our results show that the same gene seems to be affected in both Finnish and non-Finnish CNF populations. However, in the latter the mutation-carrying chromosomes descend from different ancestors without evidence of a founder effect.

Prenatal screening for congenital nephrosis in east Finland: results and impact on the birth prevalence of the disease

Congenital nephrosis of the Finnish type (CNF) is inherited as an autosomal recessive trait which maps to the long arm of chromosome 19. The disease causes massive proteinuria, and renal transplantation in early neonatal life is the only effective treatment. Prenatal diagnosis, usually in high-risk families, depends on the analysis of alpha-fetoprotein (AFP) levels in maternal serum (MS) or amniotic fluid (AF). We studied the effectiveness of MSAFP measurement as a method of screening all pregnant women for congenital nephrosis. Between 1 January 1979 and 31 December 1992, all pregnant women (N = 110,858) attending maternity care units in East Finland were offered serum AFP measurement as part of a screening programme. All patients whose MSAFP value was > or = 2.5 multiples of the median (MOM) at 15-18 weeks' gestation were given an ultrasound examination and if no morphological abnormality was found, they were then offered amniocentesis. Altogether, 105,880 pregnant women (96 per cent) in East Finland participated in the screening for CNF. A total of 47 cases of CNF were diagnosed during the study period. Elevated AFP concentrations in maternal serum and amniotic fluid (> or = 2.5 MOM) were found in all screened (44/105,880) affected pregnancies except one. The most typical feature of a CNF pregnancy was a very high AFP concentration in the amniotic fluid. As a result of the screening, the prevalence at birth of CNF decreased from 1:2600 to 1:11,086. The possibility of CNF has to be taken into account in pregnancies with a ¿false-positive' elevated AFP result (normal ultrasound and no detectable acetyl cholinesterase).

Amniotic alpha-fetoprotein in the prenatal diagnosis of congenital nephrotic syndrome of the Finnish type

Congenital nephrosis of the Finnish type (CNF) is rare outside Finland, where the incidence may be as high as 1 in 2000 live births. Neonates with the disorder develop renal failure within the first months of life and without renal transplantation, the prognosis is extremely poor. This case report describes a woman's three pregnancies, two of which were affected with CNF.

Glycosaminoglycans in urine and amniotic fluid in congenital nephrotic syndrome of the Finnish type

The heparan sulphate proteoglycan (HSPG) of the glomerular basement membrane (GBM) is considered to be mainly responsible for the charge selectivity of the GBM; decreased HSPG results in a decreased anionic charge of the GBM with increased heparan sulphate (HS) in the urine and is believed to be responsible for the proteinuria of the congenital nephrotic syndromes (CNS). Urinary HS and chondroitin sulphate (CS) concentrations in children with CNS of the Finnish type (CNF) and the total glycosaminoglycans (GAG) in amniotic fluid of CNF pregnancies were measured by three methods: Alcian blue, Safranine O and uronic acid assays. The total urinary GAG in CNF and other nephrotic patients was comparable to controls with all three methods. Urinary CS and HS in CNF did not differ significantly from controls. Total amniotic fluid GAG was also similar in CNF and control pregnancies. These results suggest some pathogenetic mechanism other than loss of glomerular HS chains in urine for the proteinuria of CNF.

Congenital nephrosis in low-risk pregnancies

Congenital nephrosis is an autosomal recessive disorder requiring neonatal renal transplant for survival. The postnatal diagnosis rests upon the electron microscopic evaluation of the epithelial foot processes and basal membrane of the glomeruli. The prenatal diagnosis can be suspected in the presence of a positive family history with an amniotic fluid (AF) alpha-fetoprotein level greater than 5 standard deviations (SD) above the population mean accompanied by a negative AF acetylcholinesterase, absent haemoglobin F, and an unremarkable fetal sonographic examination. We reviewed our series of seven cases of congenital nephrosis fulfilling the above criteria; four cases had negative family histories, and in two cases the diagnosis of congenital nephrosis was further supported by the presence of elevated AF albumin concentrations. We conclude that (1) the prenatal diagnosis of congenital nephrosis is feasible in a low-risk population, and (2) an elevated AF albumin concentration may represent an additional marker for the diagnosis of congenital nephrosis, even though false-negative results have been reported.

Exclusion of eight genes as mutated loci in congenital nephrotic syndrome of the Finnish type

The congenital nephrotic syndrome of the Finnish type (CNF) is an autosomal recessive disease characterized by massive proteinuria already at birth. The gene locus defective in CNF was searched for using polymorphic markers of candidate genes coding for components of the basement membrane (BM). The linkage analyses in 17 Finnish CNF families demonstrated exclusion of obligatory recombination events between the disease and eight genes coding for BM components. The genes coding for the alpha 1(IV), alpha 2(IV), alpha 3(IV) and alpha 4(IV) chain of type IV collagen, the B1e, B2e and B2t chains of laminin, as well as the BM heparan sulfate proteoglycan core protein were all excluded in this Finnish family material. Since the defect is not in any of the genes coding for major components of BM, the identification of the gene defect will most probably reveal a new gene important for the development and function of the glomerular basement membrane.

Elevated maternal serum AFP and normal ultrasound: what next?

Given the discovery of intracranial changes observed in fetuses with open spina bifida, the wisdom of routinely performing amniocentesis on persons with unexplained maternal serum alpha-fetoprotein elevations is now being questioned. The detection rate for spina bifida with a targeted ultrasound examination is greater than 95%. Yet one must also consider the sensitivity of ultrasound in detecting other anomalies, such as ventral wall defects and fetal karyotype anomalies. Although the sensitivity of ultrasound for neural tube defects has improved dramatically in recent years, it cannot detect all chromosome or structural anomalies that may be detected by amniocentesis. Therefore, patients should be made aware of their specific risks following a targeted ultrasound and offered the option of amniocentesis.

Quality specifications for S-AFP and S-HCG-beta determinations for screening of fetal abnormalities

High levels of maternal serum alpha-1-fetoprotein (S-AFP) are associated with fetal structural abnormalities like neutral tube defects and congenital nephrosis. It has a very high detection rate when used for screening of these diseases. On the other hand, the low levels of maternal S-AFP act as a marker of many fetal chromosomal aberrations. The detection rate of S-AFP alone for the screening of Down's syndrome is low. Wald et al. have shown that the addition of the determination of maternal serum chorionic gonadotrophin (S-HCG-beta) to S-AFP analysis, and using a computer program for risk estimation increases the detection rate for Down's syndrome to about 57% with a false positive rate of 5%. In this study we present the results of our screening program for structural fetal defects and chromosomal aberrations in Eastern Finland, and describe the standardization and quality control of maternal serum AFP and HCG-beta analysis.

Second-trimester maternal serum alpha-fetoprotein levels and the risk of subsequent fetal death

BACKGROUND

The finding of an elevated level of maternal serum alpha-fetoprotein during the second trimester of pregnancy may indicate that the fetus has died or is about to die. It is uncertain, however, whether the finding is associated with an increased risk of fetal death later in gestation independent of known causes of elevation, such as the presence of neural-tube defects or multiple gestation.

METHODS

To address this question, we performed a case-control study of 612 women whose pregnancies ended in fetal death and 2501 women who gave birth to live infants, using reports from California vital statistics for 1987. All the women had signleton pregnancies and alpha-fetoprotein screening in the second trimester.

RESULTS

Women with elevated levels of serum alpha-fetoprotein in the second trimester of pregnancy had an increased risk of fetal death, and the risk was increased until term. Women with the highest levels of serum alpha-fetoprotein--greater than or equal to 3.0 times the median value--had a very high risk of fetal death (odds ratio, 10.4; 95 percent confidence interval, 4.9 to 22.0) as compared with women who had normal levels of alpha-fetoprotein. Maternal serum alpha-fetoprotein levels that were 2.0 to 2.9 times the median were also associated with an elevated risk of fetal death (odds ratio, 2.4; 95 percent confidence interval, 1.7 to 3.4). Elevated levels of alpha-fetoprotein were especially likely to be associated with fetal death in cases in which maternal hypertension or placental infarction was also present. CONCLUSIONs. An unexplained elevated level of maternal serum alpha-fetoprotein in the second trimester of pregnancy is associated with an increased risk of subsequent fetal death, up to four to five months after alpha-fetoprotein screening.

Detection and enumeration of colonic mucosal cells in amniotic fluid using a colon epithelial-specific monoclonal antibody

Since its introduction, prenatal diagnosis of chromosomal and metabolic disorder by midtrimester amniocentesis has relied upon the use of a mixture of fetal cells obtained from amniotic fluid. Little knowledge has been gained in the sorting of these cells for diagnosis of tissue-specific disorders. In an attempt to determine the contribution of fetal colonic mucosal cells to the overall amniocyte population, we used the colonic epithelial-specific monoclonal antibody (MC-Ab) 7E12H12, IgM isotype. Specimens of the small intestine, colon, buccal mucosa, kidney, urinary bladder, and umbilical cord were obtained from electively aborted normal fetuses of 12-28 weeks' gestation. All of these specimens were examined with 7E12H12 by the immunoperoxidase technique. The MC-Ab reacted with the colonic epithelial cells but not with any of the other tissues. In addition, 40 amniotic fluid samples obtained from women between 16 and 18 weeks of gestation, who underwent amniocentesis because of advanced maternal age, were tested using a fluorescent activated cell sorter. Among the amniotic fluid specimens examined, 18.4 +/- 10.3 per cent cells reacted with 7E12H12. Double immunofluorescence studies revealed that all Mc-Ab-stained cells contained secretory component, confirming that they were epithelial in origin. All fetuses whose amniotic fluid was analysed had normal karyotypes and amniotic fluid alpha-fetoprotein levels that were also normal. This study demonstrates that cell-specific Mc-Ab can be used to detect colon cells in the amniotic fluid and that colon cells contribute significant numbers in the mixture of amniotic fluid cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Prenatal diagnosis of single gene disorders in northern Finland

Prenatal diagnosis of single gene disorders is challenging because of the multidisciplinary diagnostic approach and the genetic counselling needed. Out of 3100 pregnancies of northern Finnish women studied for early detection of congenital defects or genetic disease, 110 were at risk for and 15 were unexpectedly found to carry a fetus with a single gene disorder. Seven of the 21 diseases studied were typically representative of inherited diseases in northern Finland. The diagnostic approaches used included fetal ultrasonography, analysis of the components of the amniotic fluid, fetal enzyme analysis, fetal karyotyping for the fragile X syndrome, and fetal DNA analysis. Altogether, 50 pregnancies were found to be affected; 11 of these were continued because the diagnosis was too late for termination, and seven because the parents wanted it. Prenatal diagnosis of severe hereditary disease can be enhanced by improving the detection of pregnancies at risk, and by developing methods for earlier fetal diagnosis.

Kazal type trypsin inhibitor in amniotic fluid in fetal developmental disorders

The amniotic fluid concentrations of the Kazal type trypsin inhibitor were studied in pregnancies with fetal developmental disorders. The samples were obtained by amniocentesis between 14 and 19 weeks of gestation. In cases with fetal malformations, the level was below the normal 10th centile in 15 out of 28 cases (54 per cent, p less than 0.05) and above the normal 90th centile in 2 cases (7.1 per cent). Low values were common in cases with intrauterine fetal death or congenital nephrosis. The levels were normal in fetal chromosomal aberrations.

Maternal serum alpha-fetoprotein levels in a triplet pregnancy with 2 papyraceous fetuses

Serum Alpha-Fetoprotein (AFP) was found to rise to exceedingly high levels in a case of triplet pregnancy after two fetuses died in the 21st week of gestation. The surviving infant was born in the 36th week accompanied by the two fetus papyracei. By the time the process of mummification of the two dead fetuses appeared to be complete on ultrasound, the maternal AFP level had returned to the normal range for singleton pregnancies. HCG, hPL, and estriol and the coagulation profile remained within the normal range throughout the pregnancy.

Accumulation of laminin and type IV collagen in the kidney in congenital nephrosis

The aim of this study was to evaluate qualitatively the occurrence of the basement membrane proteins laminin and type IV collagen in the kidneys of ten infants with congenital nephrotic syndrome of the Finnish type (CNF) aged from 3 to 23 months and to compare the results with those for age-matched controls. A slow accumulation of basement membrane (BM) material occurred in the glomerular mesangium, the peripheral capillaries, around atrophied tubules, and the renal vessels in the course of the disease. The staining pattern of accumulated material depended on the duration of the disease and subsequent renal parenchymal damage. Young CNF patients with slight morphological changes in the kidney had only focal and minimal increases in the amounts of mesangial matrix, but as the disease advanced, so the BMs of the glomerular capillaries, renal arteries, and atrophied tubules also became involved and were thicker than normal. The staining reaction was in all patients similar with antibodies against the fragment P1 of laminin and the 7-S domain of type IV collagen. The accumulation of BM material in CNF kidneys is regarded as a secondary phenomenon induced by an unknown pathogenetic defect in the metabolism of some BM component.

Congenital nephrotic syndrome (Finnish type)

The case was a one year and four months old boy, who had been diagnosed as congenital nephrotic syndrome on the 4th day of life. He died of septicemia from peritonitis. Large pale kidneys, dilated trunk of pulmonary artery, and thickened left atrial endocardium were observed at autopsy. Renal histology seemed to be compatible with congenital nephrotic syndrome of the Finnish type. Viral antigens of herpes simplex type 1 and varicella-zoster in paraffin-embedded sections were proven to be negative. Besides renal change, increased number of pancreatic islets without hypertrophy was noticed.

Maternal serum alpha-fetoprotein screening for neural tube defects. Report of a combined study in Germany and short overview on screening in populations with low birth prevalence of neural tube defects

The basis of maternal serum alpha-fetoprotein (AFP)-screening for neural tube defects is discussed. A report is given of a large scale screening study in the Federal Republic of Germany combining the experiences in Giessen and Hannover on over 50,000 pregnant women, about evenly distributed among both centers. Published and known forthcoming data from other low incidence populations, particularly of European countries, are reviewed briefly. The conclusion is reached that general screening could effectively be instituted and in the final result should also be cost-beneficial.

Antenatal screening for congenital nephrosis in Finland by maternal serum alpha-fetoprotein

In the Kuopio and North-Karelia districts of Finland 10724 pregnancies were screened for congenital nephrosis by maternal serum alpha-fetoprotein (AFP) measurement. Outcome was known for 10504 (98%) pregnancies, of which 509 (4 X 8%) had a serum AFP level greater than or equal to 2 X 5 multiples of the normal median (MoM) at 15-18 weeks gestation. After exclusion of those women who had a normal serum AFP level (less than 2 X 5 MoM) in a second sample, 'wrong dates' or multiple pregnancy, 267 (2 X 5%) remained with a high serum AFP level. Amniocentesis was carried out in 225 (2 X 1%) and 16 women had an amniotic fluid AFP level greater than 10 SD above the normal mean. In this group there were six fetuses with congenital nephrosis (four confirmed and two suspected), six other serious malformations (including an intrauterine death) and four without obvious abnormality. In the 98% pregnancies followed up there were no infants with congenital nephrosis that had been missed. Babies with congenital nephrosis require permanent hospitalization and have a mean survival of 8 months. In Finland, within certain areas, the birth prevalence is as high as 1 in 2600 per year. In such areas maternal serum AFP measurement appears to be a useful method of screening for congenital nephrosis. The service was also well accepted since 94% of the women with raised serum AFP levels wished to be screened again in a future pregnancy.

Postural deformities in congenital nephrotic syndrome

Six successive cases of congenital nephrotic syndrome are described. Each one showed flexion deformities of the knees and hips, widely open anterior and posterior fontanelles, and wide separation of the skull sutures. These abnormalities were present not only in cases in which the renal histology was of the microcystic Finnish type of congenital nephrotic syndrome, but also in those in which the histological picture was one of the variants associated with congenital nephrotic syndrome. It is suggested that such abnormalities are postural deformities, possibly produced by the large placenta.

Prenatal diagnosis--a compilation of diagnosed conditions

This article provides physicians with an up-to-date listing of 182 fetal conditions diagnosed prenatally. This information is presented in two key tables: the first an alphabetical listing of the conditions and the second a grouping of them according to disease categories. The latter table also presents the technique(s) used to establish the diagnosis, as well as pertinent references. Chromosomal abnormalities, diagnosed from amniotic fluid cell karyotypes, have not been individually tabulated in either table. Current techniques utilized for prenatal diagnosis are presented (see Comment).

Renal pathology of fetal congenital nephrosis

In 15 fetuses with congenital nephrosis, distinct colloid-filled cystic tubular dilations were seen scattered in the renal cortex. Similar structures were not present in the controls. It is suggested that these structures are pathognomonic of congenital nephrosis in the fetus and make diagnosis possible even without electron microscopy.

Congenital chloride diarrhea: possibility for prenatal diagnosis

Two pregnancies, which resulted in the births of infants affected by congenital chloride diarrhea (C.C.D.) are presented. No method is available for prenatal diagnosis of this disorder. In this paper the intrauterine onset of diarrhea is confirmed by amniofoetography and high bilirubin values in amniotic fluid. In the second case the amniotic fluid alpha-fetoprotein (A.F.P.) was detected to be abnormally high at the 29th gestational week.

Significance of elevated mid-trimester maternal plasma-alpha-fetoprotein values

In a prospective trial of 15,481 pregnancies, 667 women (4.3%) had two sequential mid-trimester plasma-alpha-fetoprotein (A.F.P.) values above 2 times the median. The outcome of these pregnancies was open neural-tube defect (12.4%), birthweight less than 2.5 kg (10.3%), twins (9.8%), fetal wastage (9.5%), perinatal death (2.6%), other (1.3%), and "normal" singleton (54.1%). At higher A.F.P. cutoffs the proportion of "normal" singleton pregnancies declined rapidly, being 19% at 3 times the median and 9% at 4 times the median. If it is assumed that ultrasonography and amniotic-fluid A.F.P. assay can detect twins and most cases of neural-tube defect, the outcome of the residual pregnancies is still strongly influenced by plasma-A.F.P. level. Thus at a cut-off of 4 times the median two-thirds of the pregnancies in this residual group will end in spontaneous abortion, stillbirth, or neonatal death. It is suggested that counselling of women taking part in A.F.P. screening programmes should be strongly influenced by maternal plasma-A.F.P. levels, even if ultrasonographic findings and amniotic-fluid levels are normal.

Prenatal diagnosis of polycystic kidneys and encephalocele (Meckel syndrome)

Two unrelated families are presented with repeated occurrences of a congenital syndrome of which the main stigmata were polycystic kidneys and occipital encephalocele (Meckel syndrome). Prenatal diagnosis, followed by interruption of pregnancy, was performed in one case. The diagnosis was based on an increase of amniotic alpha-fetoprotein (AFP), and on the mode of growth and cell types of cultured amniotic cells. In another similarly examined case the diagnosis was suspected, but the parents did not wish the pregnancy to be interrupted. The child was stillborn and malformed. AFP values are presented and discussed in relation to the observed malformations. Neural tube defects are associated with an increase of AFP in amniotic fluid, but, as in normal pregnancies, the values decrease with increasing gestational age. On the other hand, kidney malformations seem to be associated with AFP values which remain high or even increase with increasing gestational age.