Dental abnormalities in Schimke immuno-osseous dysplasia.

Described for the first time in 1971, Schimke immuno-osseous dysplasia (SIOD) is an autosomal-recessive multisystem disorder that is caused by bi-allelic mutations of SMARCAL1, which encodes a DNA annealing helicase. To define better the dental anomalies of SIOD, we reviewed the records from SIOD patients with identified bi-allelic SMARCAL1 mutations, and we found that 66.0% had microdontia, hypodontia, or malformed deciduous and permanent molars. Immunohistochemical analyses showed expression of SMARCAL1 in all developing teeth, raising the possibility that the malformations are cell-autonomous consequences of SMARCAL1 deficiency. We also found that stimulation of cultured skin fibroblasts from SIOD patients with the tooth morphogens WNT3A, BMP4, and TGFß1 identified altered transcriptional responses, raising the hypothesis that the dental malformations arise in part from altered responses to developmental morphogens. To the best of our knowledge, this is the first systematic study of the dental anomalies associated with SIOD.

[Fetal nephro-/uropathy: a retrospective analysis of 124 cases seen in the period from 1996 to 2002]. / Fetale Nephro-/Uropathien: Retrospektive Analyse von 124 Fällen, erfasst im Zeitraum von 1996 bis 2002.

BACKGROUND: The embryological development of the kidneys and the urinary tract follows a complex choreography. Disorders are quite common. The incidence of disorders amounts to 0.3 - 0.8 % of live-born infants. In addition, several chromosomal anomalies are combined with renal malformations. The poor prognosis of some of these diseases is reflected in a perinatal mortality of 6.3 %. PATIENTS AND METHODS: Retrospectively 124 cases with fetal nephro-/uropathy detected by prenatal ultrasonography between 1996 and 2002 were analyzed. Features of hypo-dysplastic kidneys (uni- or bilateral) were seen in 21 cases. Multicystic kidney disease (uni- or bilateral) existed in 40 fetuses. In some cases of multicystic or dysplastic kidney diseases, extrarenal malformations were combined. 21 fetuses suffered from autosomal recessive polycystic kidney disease. 18 male unborns showed the typical picture of intravesical obstruction due to posterior uretheral valves. The prune belly syndrome was seen 4 times. Hydronephrotic kidneys with more than 5 mm pelvic dilatation were detected in 13 cases. Renal agenesis led to a lethal outcome perinatally in 5 cases. One child died of bilateral thrombosis of renal artery and venous system. RESULTS: The high incidence of diseases with a poor prognosis accounts for the high mortality of 50.8 % (intrauterine or postnatal death, induced abortion). Such a fatal outcome was observed in autosomal recessive polycystic kidney disease, bilateral multicystic dysplastic kidney disease, bilateral renal dysplasia combined with severe extrarenal malformations, intravesical obstruction, renal agenesis and bilateral thrombosis of the renal vessels. Only 60 children survived. Of these 26 needed urological surgery. 15 suffered from progressive renal insufficiency. During a follow-up of 8 - 58 months only 44 exhibited a normal renal function. CONCLUSIONS: Such complex renal and urological diseases in the fetus require an interdisciplinary management of the pregnancy.

Genetic variations of the SLC7A9 gene: allele distribution of 13 polymorphic sites in German cystinuria patients and controls.

Cystinuria is a hereditary disorder of cystine and dibasic amino acid transport across the luminal membrane of renal tubules and intestine, resulting in recurrent nephrolithiasis. While mutations in the SLC3A1 gene cause type I cystinuria, patients with non-type I cystinuria carry mutations in the SLC7A9 gene. Both gene products form the renal amino acid transporter rBAT/b0,+AT affected in cystinuria. In the present study a total of 59 patients with different ethnic background were screened for sequence variations in SLC7A9, out of these 32 were of German origin. For determination of allele frequencies of detected polymorphisms, 58 healthy German controls were investigated. Molecular-genetic analysis was performed using single-strand conformation polymorphism analysis, restriction assays and sequencing. Allele frequencies were analyzed statistically for the detected polymorphisms. In addition to the 6 already known variants we identified 7 new polymorphisms. Statistical analyses showed a significantly different distribution of alleles between German patients and German controls in case of the polymorphisms c. 147C>T (exon 2), c.386C>T (exon 3), IVS3+22T>G, c.584C>T (exon 4), c.610T>C (exon 4), c.692C>T (exon 5), c.852C>A (exon 6) and c.872C>T (exon 6). In summary, our results show that cystinuria is a complex disease which is not only caused by mutations in SLC7A9 and SLC3A1, but also influenced by other modifying factors such as variants in SLC7A9.

Familial hypomagnesemia-hypercalciuria in 2 siblings.

Familial hypomagnesemia-hypercalciuria with nephrocalcinosis and renal insufficiency in childhood is a rarely described disease. Two siblings of consanguineous Tunesian parents (first cousins), a 2-year-old boy and a 4-year-old girl presented with renal insufficiency and severe bilateral nephrocalcinosis. Both were found to have decreased serum and intracellular magnesium concentrations, increased urinary excretion of magnesium and calcium, mild glomerular and severe tubular proteinuria and low citrate excretion in urine. Pathological biochemical findings and the severity of nephrocalcinosis of the boy compared to findings of the sister were strongly marked, Histology of the boy's kidney showed severe medullary nephrocalcinosis, tubular atrophy, focal lymphoplasmacellulary infiltration, focal cortical fibrosis, immature glomerula, segmental and global glomerulosclerosis. Subsequent mutation analysis revealed a homozygous frameshift mutation in the gene paracellin-1 in both affected individuals. Therapy consisted of sodium bicarbonate, cholecalciferol, calcitriol, hydrochlorothiazide, citrate salts and oral magnesium administration. Hypercalciuria decreased in both children by therapy with thiazide diuretics, but hypomagnesemia was unresponsive to magnesium administration. After a 32-month follow-up the boy commenced hemodialysis at the age of 5 years, whereas his sister showed no decline in renal function.

2,8-Dihydroxyadenine urolithiasis in a patient with considerable residual adenine phosphoribosyltransferase activity in cell extracts but with mutations in both copies of APRT.

We have examined the mutational basis of adenine phosphoribosyltransferase (APRT, EC 2.4.2.7) deficiency (MIM 102600) in a patient of Polish origin who has been passing 2,8-dihydroxyadenine (DHA) stones since birth, but has considerable residual enzyme activity in lymphocyte extracts. The five exons and flanking regions of APRT were amplified by PCR and then sequenced. A single T insertion was identified at the intron 4 splice donor site (TGgtaa to TGgttaa:IVS4+2insT) in one allele from the proband, his mother, and brother. A G-to-T transversion in exon 5 (GTC-to-TTC:c.448G>T, V150F) was identified in the other allele, and this mutation was also present in one allele from the father and the paternal grandmother. Tru91 and AvaII digestions of PCR products spanning exons 4 and 5, respectively, confirmed the mutations. The mother was heterozygous for an intragenic TaqI site, but all other family members were homozygous for the presence of this site. IVS4+2insT, located on the allele containing the TaqI site, has been identified previously in several families from Europe, suggesting a founder effect, but the substitution in exon 5 is a novel mutation. IVS4+2insT is known to result in complete loss of enzyme activity, and our results suggest that V150F produces an enzyme that is nonfunctional in vivo but has considerable residual activity in vitro.

Manifestations and treatment of Schimke immuno-osseous dysplasia: 14 new cases and a review of the literature.

UNLABELLED: Schimke immuno-osseous dysplasia (SIOD) is a rare autosomal recessive spondylo-epiphyseal dysplasia. The characteristic features of SIOD include 1) short stature with hyperpigmented macules and an unusual facies, 2) proteinuria with progressive renal failure, 3) lymphopenia with recurrent infections, and 4) cerebral ischaemia. Although 25 patients have been reported with this disorder, the clinical course and phenotype of SIOD are not well characterized. This report summarizes the clinical findings, course and treatment of reported patients and includes 14 additional patients with SIOD. We emphasize the high incidence of cerebral ischaemia and ocular abnormalities, define the high incidence of thyroid dysfunction and blood cytopenia, and confirm the absence of effective and durable medical therapies. CONCLUSION: Schimke immuno-osseous dysplasia is a multi-system autosomal recessive disorder with variable expression that affects the skeletal, renal, immune, vascular, and haematopoietic systems. Medical therapy is limited especially for more severely affected individuals.

Renal insufficiency in neonates after cardiac surgery.

Renal failure after cardiac surgery using cardiopulmonary bypass (CPB) is well understood for infants, children and adults. The perioperative risk factors after CPB for immature kidneys in newborns are not well known. This retrospective study investigates perioperative risk factors for renal insufficiency in neonates. I) Preoperative: Age; weight, performed angiography, amount of dye used in angiography, renal disease and creatinine. II) Intraoperative: Duration of operation, duration of MAP < 40 mmHg, use of deep hypothermia, in-out fluid balance, duration of CPB, duration of circulatory arrest and cross-clamp time. III) Postoperative: Creatinine, use of catecholamines, use of nitroglycerine (NG) or phosphodiesterase inhibitors (PDI) and additional antibiotics. From Jan. 1990 to Dec. 1994 50 neonates underwent cardiac surgery using CPB (n = 23 transposition of the great arteries; n = 4 pulmonary atresia; n = 6 critical pulmonary stenosis; n = 5 hypoplastic left heart syndrome; n = 3 Ebstein's anomaly; n = 2 interrupted arch with hypoplastic left ventricle; n = 2 single ventricle; n = 1 each: double outlet right ventricle, tricuspid atresia, critical aortic stenosis, rhabdo-myosarkoma, corrected transposition of the great arteries.) Thirty-one patients entered the study. Depending on the postoperative creatinine level two groups (group I: creatinine <1 mg/dl and group II: >1 mg/dl) were created. The diureses between the two groups did not differ. Comparing the patients of group I vs. group II, patients of group I were younger (mean age: 7.7 d. vs. 11.4 d), lighter (mean weight: 3260 g vs. 3430 g), less had angiography (44% vs. 77%), received more dye (mean amount: 14 ml vs. 7 ml), the duration of MAP < 40 mmHg while on CPB was longer (mean duration 3 min vs. 21 min), more patients were operated on using deep hypothermia (55% vs. 27%), the postoperative in-out-fluid balance was more positive (mean balance +413 ml vs. +221 ml), received postop. more frequently high doses of catocholamines and less common NG or PDI, but more often additional antibiotics. The duration of circulatory arrest (mean time: 60 min vs. 55 min) and cross clamp time (mean time: 68 min vs. 65 min) seems not to be a risk factor and vasodilators given simultaneously with catecholamines may have preventive effects on postoperative renal insufficiency. Immature kidneys may play an outstanding role in the susceptibility of damaging factors. Further investigation with a larger number of patients allowing to obtain statistical significant risk factors are required.

The addition of aminoacids and phosphate to hemodiafiltration solutions in newborns with hyperammonemic coma.

A child with carbamyl-phosphate-synthetase defect who died after prolonged continuous hemodiafiltration in deep coma proved to have high aminoacid losses despite aminoacid infusion. We think that this results from high small-solute clearance during hemodialysis. In order to prevent these inevitable catabolic side-effects we decided to add aminoacids to the dialysate and substitution fluid in these children with metabolic diseases. Additionally we propose to add phosphate in order to avoid depletion. The aim is to achieve anabolic or at least non-catabolic hemodiafiltration.

[Management of children with prenatally diagnosed urinary tract abnormalities]. / Betreuung von Kindern mit pränatal diagnostizierten Harnwegfehlbildungen.

Between 1984 and 1991, antenatal ultrasound scanning detected urinary tract malformations in 126 infants, who were investigated and treated postnatally in the childrens' hospital of the Westfälische Wilhelms-University Münster. 10 out of 126 children with urogenital changes, died in the first hours after birth, due to pulmonary hypoplasia (Potter's sequence), 1 further infant died later after cardiac operation, and another died of megacystic-megaureter-hypoperistaltic-syndrome. In the first months after birth 71 (61%) of 116 infants underwent urological surgery; 12/116 infants (10.3%) had severe bilateral kidney changes, some of them with severe deficiency of amniotic fluid before birth. 6/116 infants (5.2%) had chronic renal insufficiency, 2 of them will have to be dialyzed in early childhood and longterm, 14 patients (12%) are threatened by chronic renal failure. 14 patients (12%) developed severe arterial hypertension, all had to be treated with antihypertensive drugs, in 5 of them hypertension subsided after unilateral nephrectomy, another five had transient hypertension, but four require continued medical treatment. We describe the prenatal ultrasound findings, compared them with diagnosis after birth, illustrate diagnostics, plans of therapy, urological surgical interventions and nephrological consequences. Benefits and limitations of antenatal ultrasonography for the detection of urinary tract malformations and the treatment of those malformations before and after birth are discussed. In utero diagnosis of severe urinary tract abnormalities allows treatment of these infants immediately after birth, furthermore the prevention of severe infections, additional damage of renal tissue, and early diagnosis and treatment of arterial hypertension and metabolic imbalances caused by chronic renal insufficiency in early childhood.