Y-chromosome markers in Turner syndrome: Screening of 130 patients.

BACKGROUND: The presence of Y-chromosome material in patients with Turner syndrome (TS) is a risk factor for the development of gonadoblastoma. Cytogenetic analysis detects Y-chromosome mosaicism in about 5% of Turner patients. However, if Y-chromosome sequences are present in only a few cells, they may be missed by routine analysis. The use of molecular techniques to detect the presence of Y-chromosome fragments in such patients is becoming increasingly important. AIM: The objective of our study was to analyze cryptic Y-chromosome derivatives in Hungarian TS patient population by real-time PCR (RT-PCR). SUBJECTS AND METHODS: Cytogenetic and RT-PCR methods were used to examine peripheral blood DNA of 130 Hungarian patients with TS for the presence of Y-chromosome. With RT-PCR, 4 regions throughout the Y-chromosome were analyzed. RESULTS: Initial cytogenetic karyotyping assessing 10-50 metaphases revealed 3 patients with Y-chromosome positivity. RT-PCR revealed further 6 patients with Y-chromosome, who were initially considered as Y-negatives by standard kayotyping. The consecutive cytogenetic analysis of a large number (about 100) of metaphases (in 5 patients) and/or FISH (in 6 patients) however, also confirmed the presence of the Y-chromosome in these patients. Prophylactic gonadectomy was carried out in all 9 patients and 1 of them was diagnosed as having bilateral gonadoblastoma without clinical symptoms. CONCLUSIONS: We recommend a routine molecular screening for hidden Y-chromosome sequences in Turner patients, who are negative for Y-chromosome by conventional cytogenetic analysis, in order to calculate the future risk of developing gonadoblastoma.

Isolation of inhibin from ovine follicular fluid using reversed-phase liquid chromatography.

This report describes the application of high performance liquid chromatography (HPLC) and associated techniques to the isolation of inhibin from ovine follicular fluid (oFF). Two modes of HPLC have been assessed. High speed gel permeation chromatography on a Waters I-125 support showed that at pH 7.0 inhibin bioactivity was associated with an approx. 80000 mol. wt protein fraction which co-eluted with the bulk of the protein in oFF and gave a yield of 30-44% of the applied activity. Reversed-phase HPLC (RP-HPLC) of a peptide-rich fraction extracted from oFF was also investigated. Using analytical liquid chromatography on octadecylsilylsilica (ODS-silica), two distinct inhibin bioactive fractions were obtained, with a resultant purification of 23-fold and 3-fold respectively and an overall recovery of 8.5%. These results demonstrate that RP-HPLC may be employed as a direct and rapid technique for the isolation of inhibin from oFF.

The specificity of inhibin bioassay using cultured pituitary cells.

It has been established that the inhibition of the cellular content of FSH in cultured pituitary cells can be used as a sensitive and precise bioassay for inhibin. During studies on the inhibin content of human plasma, FSH suppression was noted to occur together with LH suppression. Further studies revealed that where combined FSH and LH suppression occurred, cytological changes in the pituitary cells suggestive of toxicity were found, indicating non-specific effects of these substances. Charcoal treatment or gel filtration of seminal plasma removed or separated the toxic substances from the inhibin activity, the latter characterized by FSH suppression parallel to the standard preparation, no LH suppression and no light-microscopic changes in pituitary cells. It is recommended that careful evaluation of all inhibin bioassay systems should be undertaken to detect substances producing non-specific effects and additional guidelines for the assessment of specificity are suggested.

Red cell sodium-lithium countertransport and blood pressure in children with insulin-dependent diabetes mellitus.

Sodium-lithium countertransport and blood pressure responses, maximal elevated plasma norepinephrine concentrations induced by acute physical work load and the carbohydrate metabolic state were analyzed in 40 children suffering from insulin-dependent diabetes mellitus (IDDM). Patients were selected according to the duration of the disease to get a horizontal insight into the progression of the diabetes. Sixteen healthy children served as controls. Sodium-lithium countertransport (Na-Li CT) was 281 +/- 64 mumol/l red blood cells (RBC) per hour in the control group. Na-Li CT was elevated in all diabetic groups (newly diagnosed: 455 +/- 48; diabetics for 5-7 years: 495 +/- 48; diabetics for 10-13 years: 470 +/- 36). Plasma norepinephrine concentration increased during physical exercise, the elevation was more pronounced in diabetic children being 13.5 +/- 10.4, 10.1 +/- 5.0 and 12.3 +/- 5.4 nmol/l in the three diabetic groups, respectively, which differed significantly from that of controls (7.94 +/- 2.9; P < 0.01). Systolic blood pressure increased significantly during physical exercise in each group. However, maximal elevated systolic blood pressure was higher in children who had diabetes for more than 10 years than in controls (158 +/- 11 vs. 137 +/- 9.7 mmHg; P < 0.001). Na-Li CT correlated positively with the maximal systolic blood pressure measured during physical exercise in those diabetic children who suffered from diabetes for more than 5 years. High activity of Na-Li CT in combination with elevated blood pressure and high plasma concentration of norepinephrine induced by acute physical exercise may represent a risk of renal/vascular complications in patients suffering from IDDM.

Developmental changes in erythrocyte Na(+),K(+)-ATPase subunit abundance and enzyme activity in neonates.

AIM: To study the relation between erythrocyte Na(+),K(+)-ATPase subunit isoform composition, Na(+),K(+)-ATPase activity, and cation pump function in preterm and term neonates. DESIGN: Erythrocyte Na(+),K(+)-ATPase subunit isoform abundance, Na(+),K(+)-ATPase activity, and cation pump function were studied in blood samples obtained from 56 preterm neonates of 28-32 weeks gestation (group 1), 58 preterm neonates of 33-36 weeks gestation (group 2), and 122 term neonates (group 3) during the first two postnatal days. RESULTS: alpha(1) isoform abundance was higher and beta(2) isoform abundance was lower in group 1 than in group 3 (p = 0.0002). alpha(2) and beta(1) isoform abundance did not change with maturation and there was no evidence for the presence of the alpha(3) isoform. Gestational age was inversely related to Na(+), K(+)-ATPase activity (p = 0.0001) and directly related to intracellular Na(+) concentration (p = 0.0025). CONCLUSIONS: Expression of the alpha(1) and beta(2) Na(+),K(+)-ATPase subunit isoforms is developmentally regulated. The increased abundance of alpha(1) isoforms of immature neonates translates to increased ATPase activity. The lower intracellular Na(+) concentration of immature neonates suggests that their erythrocyte Na(+),K(+)-ATPase cation pump function may also be increased.

Tubular proteinuria in IgA glomerulonephritis.

In the renal biopsy samples of some patients with IgA glomerulonephritis (IgA GN), tubulointerstitial changes and a significant correlation between these changes and the serum creatinine levels had been observed earlier. In order to get an insight into the function of the tubules, 45 patients with IgA GN have been examined for proteinuria with special reference to low molecular weight (LMW) proteins, also called tubular proteins using sodium-dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE). Thirty-seven of the 45 patients had proteinuria (200-1890 mg/day). On the basis of the middle molecular weight/high molecular weight (MMW/HMW) protein ratio, the proteinuria was non-selective in 28. Twenty-nine patients had 40-200 mg LMW protein/day in the urine. There was a statistically significant correlation between the tubulointerstitial changes seen in the renal biopsy samples (characterized by the tubulointerstitial index) and the tubular proteinuria. On the basis of these results it is suggested that in most patients with IgA GN there is, in addition to the glomerular lesion, also morphological and functional tubulointerstitial damage, which is in connection with the progression of the disease.

Prevalence of alpha1-antitrypsin phenotypes in patients with IgA nephropathy.

BACKGROUND: alpha1-antitrypsin (AAT) is the main protease inhibitor in the blood. Several different AAT phenotypes exist. The most common variant is the MM phenotype, which is also associated with normal AAT levels. The less common phenotypes with Z and S variants are associated with low AAT levels. AAT deficiency is a risk factor for pulmonary emphysema, liver impairment and some immune-mediated diseases, some of which are also associated with IgA nephropathy (IgAN). In fact, liver impairment resulting from AAT deficiency may directly contribute to renal abnormalities resembling IgAN. PATIENTS AND METHODS: We investigated AAT phenotype and AAT levels in 100 IgAN patients who did not have end-stage liver disease. Fifteen patients in our sample had secondary IgAN. We also tested for the presence of renal deposition of AAT in patients heterozygous for AAT variants as well as in a randomly chosen group of patients with MM phenotype. We checked for any association between AAT phenotype and the progression of IgAN as well as the prevalence of diseases associated with IgAN (i.e. secondary IgAN). RESULTS: Twelve patients in our sample were heterozygous for AAT variants. Phenotypes were MZ in 5 patients, MS in 3, MF in 1, ML in 2 and ME in 1 patient. AAT levels were lower in these 12 patients than in those homozygous for the M variant (1.17+/-0.46 vs. 1.44+/-0.34 g/l, p < 0.05). We found renal deposition of AAT in 2 heterozygous patients and in 1 of the 12 patients which were randomly chosen. End-stage renal (ESRF) failure developed in 3 of the 12 heterozygous patients and in 6 of the 88 homozygous patients (p = 0.07) during the follow-up. The prevalence of heterozygosity was significantly higher in patients with secondary IgAN than in those with primary IgAN ((5/15 vs. 7/85; p < 0.02). CONCLUSIONS: AAT phenotype is not associated with the risk of primary IgA nephropathy, but might have an impact on disease outcome as well as on the risk of secondary IgAN.

HbA1c levels and erythrocyte transport functions in complication-free type 1 diabetic children and adolescents.

Higher erythrocyte sodium-lithium countertransport activity (SLC) is implicated in the development of diabetic nephropathy. Altered glucose homeostasis and genetic susceptibility are claimed to play a role in the elevation of SLC. We aimed to test whether metabolic control or the genetic variants of G protein beta 3 (Gb3) subunits determine SLC and other erythrocyte transport activities in complication-free stage of type 1 diabetes. A total of 96 complication-free type 1 diabetic children and adolescents were enrolled. SLC, Na(+)/K(+)-ATPase (NAK) and Ca(2+)-ATPase (CA) were measured by functional assays in erythrocytes. Gb3-C825T polymorphism was determined by PCR-RFLP. Results were related to HbA(1c) and were compared to those of 97 healthy controls. SLC activity was higher in diabetics (387+/-146 vs. 280+/-65 mmol/RBC. hour) and correlated with HbA(1c) levels (y=0.004x+6.42, r=0.33, n=96, p<0.01). NAK and CA activities were unaltered. The prevalence of (825)T allele was similar in the patient and control groups (0.34 vs 0.37) and no differences in enzyme activities were observed between the (825)T allele-positive and negative subjects. Although metabolic control correlated with SLC, other membrane functions were not affected. Therefore we hypothesize that the relationship between advanced glycation and SLC elevation is not causative. Rather, a genetic susceptibility for the coexistence of poor metabolic control and higher SLC is more likely. However, the presence of Gb3-C825T variant is not likely to be a risk factor for SLC-elevation and altered metabolic control diabetes.

Reproducibility of erythrocyte sodium-lithium countertransport activity and ambulatory blood pressure measurements in type 1 diabetes mellitus.

We aimed to study the reproducibility of sodium-lithium countertransport [SLCT] activity and ambulatory blood pressure monitoring [ABPM] in type 1 diabetes. We did this by performing repeated measurements of SLCT activity and ABPM in 11 recent-onset diabetic children and in 11 patients with longer duration of diabetes. Both parameters were related to microalbuminuria. In the older group of diabetic children a significant correlation [r = 0.78; P<0.005] in SLCT activity between the first and second study was observed [514.3+/-186.4 vs 491.0+/-148.0 micromol/l erythrocytes/h]. Diurnal systolic and diastolic blood pressure were comparable at both time points within the same group of diabetic children [in group 1: 102.6+/-6.1 vs 108.6+/-7.6 mmHg N.S.; in group 2: 113.4+/-10.6 vs 114.0+/-7.8 mmHg N.S. Diastolic blood pressure in group 1: 57.4+/-4.8 vs 65.7+/-6.9 mmHg N.S., in group 2: 70.6+/-9.1 vs 68.5+/-5.3 mmHg N.S.]. Moreover, there was a significant correlation in both diurnal and nocturnal systolic blood pressure between the first and second study in the whole diabetic population. Both SLCT activity and blood pressure values obtained by ABPM were found to be reproducible individual characteristic markers in type 1 diabetic children.

[Long-term follow up of children with orthostatic proteinuria]. / Ortosztatikus protenuriás gyermekek tartós követése.

The authors summarize their observations of 18 children with orthostatic proteinuria. The average time of follow-up was 4 and half years. They examined body measures and renal functions of the patients and compared their blood pressure, pulse rate, electrocardiographic curve, morphological and positional conditions of kidneys in lying and standing position, as well as change of quantity and quality of proteinuria (high, middle and low molecular weight) at day time and night both in proteinuric children with and without ptosis renis and in controls. The patients were taller than the average, but their body mass was small compared to their weight. Ptosis renis was found in 11 patients. Renal functions remained good. The authors detected changes only in quantity and quality of proteinuria during of long term follow-up, the other parameters remained normal or the change was like that of the controls. They propose, that these two parameters are of prognostic importance.

[Non-ketotic hyperglycinemia]. / Non-ketoticus hyperglycinaemia.

Three children with non-ketotic hyperglycinaemia (NKH) is reported. Two patients had typical neonatal form of NKH, one patients had atypical form of NKH. The clinical symptoms laboratory findings and therapeutical approach are discussed. One of the patients with typical neonatal form of NKH is died, neuropatological examination revealed corpus callosal agenesis and diffuse hypomyelinisation. The two children treated with N-methyl-D-aspartate-antagonist drugs reached a significantly better clinical condition. The authors reviewed the data of the literature, especially focused on the therapeutical possibilities.

[Normal values of calcium and oxalate excretion in children]. / A kalcium- és oxalátürítés normálértékei gyermekekben.

Aim of the study was to establish normal values for calcium/creatinine (Ca/cr) and oxalate/creatinine (Ox/cr) ratio in infants and children. Urine probes of 416 healthy children (25 infants aged 1-7 days and 391 children aged 1 month-14.5 years) were analysed. Oxalate was measured by ion-chromatography. Urinary Ca2+/cr was normally distributed, Ox/cr had log-normal distribution. Ca/cr was the lowest in the first days of life, the highest between 7 month-1.5 years (mean +/- SD = 0.39 +/- 0.28 mmol/mmol), a slight decrease could be observed until 14 years (0.34 +/- 0.18). The highest Ox/cr values were measured during the first month of life (geometric mean/range/ = 133 /61-280 mmol/mmol/), followed by gradual decrease until 14 years (25/6-73/). The measurement of Ca2+/cr and Ox/cr in first morning urine samples is suitable for screening of hypercalciuria and hyperoxaluria. The interpretation of the values requires age specific reference values. Both calcium and oxalate determinations should be the part of the evaluation of patients with hematuria, hypercalciuria or nephrolithiasis.

[46,XX karyotype males, based on a specific case]. / A 46,XX karyotypusú férfiakról egy eset kapcsán.

Individuals with 46,XX karyotype and testicular tissue are known as XX males. They either have male phenotype or sexual ambiguity. SRY (testis determining factor) is present in 80% of the reported cases. In our patient the presence of SRY was verified by polymerase chain reaction, explaining the sex reversal.

[Life expectancy in Down syndrome infants and children with congenital heart defects, 1974-1997]. / A Down-szindrómás szívbeteg csecsemók és gyermekek életkilátása 1974-1997 között.

Authors analysed 359 cases with Down's syndrome and congenital heart defects registered between 1974-1997 in Hungary. The total death rate was 19.9% (70 cases). Mortality in the operated group (85 cases) was 10.5% (9 patients), in the non-operated group (274 cases) 22.2% (61 patients). The death rate was lower in the group with early primary reconstruction (2.3%) than in the group with palliation + reconstruction (15.3%), or in the group with only palliative procedure (20%). These results indicate that the life expectancy of infants and children with Down's syndrome and congenital heart disease after early primary reconstructive procedure is the same as in Down syndrome patients without cardiac defects. The prognosis depends on the patient's social circumstances. The results after correct surgical procedure in patients with the same cardiac defect are similar to that of the patients with or without Down's syndrome.

[Uniparental disomy 7 in the pathogenesis of Silver-Russell syndrome]. / A 7-es kromoszóma uniparentalis disomiája a Silver-Russel-syndroma kóreredetében.

The authors report the frequency and the clinical signs of uniparental disomy of chromosome 7 in Silver-Russell syndrome patients. A cohort of 73 families were typed with Short Tandem Repeat markers from chromosomes 7. In 6 patients maternal uniparental disomy 7 (UPD7) was detected. Summarising their data and those from the literature, an overall frequency of maternal uniparental disomy 7 of approximately 10% can be estimated. Allelic distribution in two of their maternal uniparental disomy 7 families indicates complete isodisomy whereas allelic patterns in the other four families are consistent with partial and complete heterodisomy, respectively. The clinical features of maternal uniparental disomy 7 patients do not show any deviation from the non-uniparental disomy 7 patients. Additionally, there was not hint for possible influences of iso- or heterodisomy, possibly associated with different stages of mosaicism. Their results demonstrate the necessity to screen SRS patients for UPD7 although the effect of UPD7 cannot be correlated to the SRS phenotype yet. Furthermore, an association between UPD for chromosomes other than 7 and SRS seems to be negligible. Vice versa, maternal UPD7 is not detectable in non-SRS patients. Therefore, testing for maternal UPD7 can be restricted to SRS families, searching for other UPDs in this population does not seem to be reasonable. Additionally, cytogenetic analysis should also be performed in SRS patients: identification of commonly involved chromosomal regions should allow narrowing down a SRS-relevant region.

[Aberrations of chromosome 18 and their significance in genetic counseling]. / A 18-as kromoszóma rendellenességeinek eredete és jelentósége a genetikai tanácsadásban.

In order to get information on the origin of chromosome 18 aberrations trisomy 18 cases were analysed as well as different chromosome 18 rearrangements. In total, their study population consisted of 100 trisomy 18 patients and their parents, 67 out of which have already been published. Additionally, seven families were analysed with structural aberrations of chromosome 18 including four patients with tetrasomy 18p. Determination of parent and cell stage of origin was performed by short tandem repeat typing (STR, microsatellites). These investigations revealed that the additional chromosomal material in the majority of the chromosomal 18 aberrations was maternal in origin (97/107). In most of the cases the nondisjunction occurred during maternal meiosis II. This was in agreement with findings of other groups. Thus, independently from the type of aberration, there was a predisposition of chromosome 18 for nondisjunction in maternal meiosis II. In this respect, chromosome 18 seemed to be unique among human autosomes. Furthermore, these results showed that molecular genetic analyses of chromosomal aberrations and their formation mechanisms were meaningful tools in genetic counselling situations: in 5 cases where cytogenetic investigations could not performed, the clinical diagnosis of Edwards syndrome could be confirmed by molecular findings. Thus, in these cases other genetic diseases with differing types of inheritance could be excluded from being the cause of the observed malformations. In a further structural rearrangement of chromosome 18, the origin could be determined as being mitotic, therefore a recurrence risk could be excluded for this couple.