Primus-Eugen Mullis

De novo loss- or gain-of-function mutations in KCNA2 cause epileptic encephalopathy.

Epileptic encephalopathies are a phenotypically and genetically heterogeneous group of severe epilepsies accompanied by intellectual disability and other neurodevelopmental features. Using next-generation sequencing, we identified four different de novo mutations in KCNA2, encoding the potassium channel KV1.2, in six isolated patients with epileptic encephalopathy (one mutation recurred three times independently). Four individuals presented with febrile and multiple afebrile, often focal seizure types, multifocal epileptiform discharges strongly activated by sleep, mild to moderate intellectual disability, delayed speech development and sometimes ataxia. Functional studies of the two mutations associated with this phenotype showed almost complete loss of function with a dominant-negative effect. Two further individuals presented with a different and more severe epileptic encephalopathy phenotype. They carried mutations inducing a drastic gain-of-function effect leading to permanently open channels. These results establish KCNA2 as a new gene involved in human neurodevelopmental disorders through two different mechanisms, predicting either hyperexcitability or electrical silencing of KV1.2-expressing neurons.

Epidemiology of Type I diabetes mellitus in Switzerland: steep rise in incidence in under 5 year old children in the past decade

Aims/hypothesis. In this nationwide prospective study we wanted to verify the trend of increasing diabetes incidence data from our earlier retrospective analysis of the military registry of Swiss men. Subjects and methods. The data collection of newly diagnosed children in Switzerland at an age younger than 15 years started in 1991. The countrywide survey used a small questionnaire which was sent back to the study centre. The questionnaire was anonymous and contained: hospital of diagnosis, initials, sex, birth date, date of diagnosis, residence, country of citizenship, and responsible physician. General data on the population were taken from publications of the Swiss Federal Statistical Office. Results. A total of 941 children below the age of 15 years with newly diagnosed Type I (insulin-dependent) diabetes mellitus were collected (434 girls, 507 boys). The incidence in children aged 0 to 14 years rose significantly between 1991 and 1999 with a yearly average increase of 5.1 %. In the age group 0 to 4 years a more than four-fold increase in incidence from 2.4/100 000 per year to 10.5/100 000 per year (p = 0.0002) was recorded, whereas the age-specific incidence in the 5 to 9-year-old and 10 to 14-year-old children did not change during the data collection period. The incidence was significantly higher in boys than in girls, whereas no difference was found between rural and urban populations. Conclusion/interpretation. The incidence of Type I diabetes is rising in children living in Switzerland but only the youngest age group of under 5 years of age is affected showing a large annual average increase of 23.8 %. [Diabetologia (2001) 44: 286–289]

Persistent microalbuminuria in adolescents with Type I (insulin-dependent) diabetes mellitus is associated to early rather than late puberty

Microalbuminuria is generally accepted to be highly predictive of overt diabetic nephropathy which is the leading cause of end-stage renal failure and, consequently, of death in patients with type 1 (insulin-dependent) diabetes mellitus (IDDM). Its early identification and therapy are exceedingly important. We studied prospectively the occurrence of microalbuminuria (MA) in relation to puberty and its pubertal stages in 164 children and adolescent patients (83 girls and 81 boys) with IDDM. Analysing 100 healthy subjects, normal values for albumin excretion (range: 0–10.1 μg/min/1.73 m2) according to sex and the different pubertal stages were defined. No significant difference between the groups were noted and, therefore, 20 μg/min per 1.73 m2 (3 SD above the mean) was generally defined as cut-off for MA. Of the patients with IDDM studied, 20% (20 females and 12 males) developed persistent MA (22.1–448.2 μg/min/1.73 m2) during the study period of 8 years. The first manifestation of persistent MA was in 69% (13 females and 9 males) during stages of early and midpuberty; and in 28% (6 females and 3 males) at a late pubertal stage or at the end of puberty. The only child who developed MA before the onset of puberty (range: 23.5–157.4 μg/min/1.73 m2) was found to have dystopic kidney. Therefore, all patients with IDDM should be screened for MA regardless of diabetes duration, sex and level of diabetes control beginning at the very first stage of puberty and neither earlier nor after puberty as suggested by the American Diabetes Association.

Prospective randomised treatment with recombinant human growth hormone in cystic fibrosis

Aim: To evaluate the efficacy and safety of treatment with recombinant growth hormone (rGH) in patients with cystic fibrosis (CF). Methods: Twenty patients with CF (aged 10–23 years) were randomised to age and sex matched treatment and control groups. The treatment group received daily subcutaneous injections of 1 IU/kg/wk rGH for 12 months. Pulmonary function (forced expiratory volume in one second (FEV1) and airway resistance), exercise capacity measured with a bicycle ergometer, body composition (dual energy x ray absorptiometry), and weight were assessed at the beginning of the study and after 6 and 12 months. Results: rGH treatment did not improve weight and pulmonary function, but lean body mass increased significantly in the treatment group. Exercise capacity increased in the treatment group from 143 (16) W (mean (SD)) to 164 (19) W after 12 months of rGH treatment. Conclusion: Treatment of CF patients with rGH for one year improved the exercise capacity significantly but not pulmonary function. The improved exercise capacity needs confirmation in a larger population before such an expensive treatment is justified.

Increased prevalence of fetal haemoglobin in type 1 (insulin-dependent) diabetes mellitus

SummaryFetal haemoglobin levels were measured in 106 patients with Type 1 (insulin-dependent) diabetes mellitus during a period of two to three years. In 15 patients (14.1%) increased fetal haemoglobin levels (>0.5%), determined by high pressure liquid chromatography, were found in contrast to 3% in a healthy control group (n: 100) of equal age distribution. In children aged over 6 years, elevated fetal haemoglobin levels were measured in 13 diabetic patients (13.3%) in contrast to none of the control group. There was no correlation between fetal haemoglobin levels and duration of diabetes, diabetic control (glycated haemoglobin) and dosage of insulin (U·kg−1, day−1). The 15 patients had a younger mean age at onset of diabetes (5.6 years) than a sex and age matched control group of diabetic patients without increased fetal haemoglobin levels (7.4 years, p<0.05). Longitudinal assessment revealed a significant decline of fetal haemoglobin levels with age (p<0.005) but a further increase in fetal haemoglobin levels were found in adolescent patients (n: 2). These data indicate a possible effect of insulin-treatment on delaying transition from fetal to adult haemoglobin synthesis or on reactivation of fetal haemoglobin production.

Insulin increases serum leptin concentrations in children and adolescents with newly diagnosed Type I diabetes mellitus with and without ketoacidosis

Aims/hypothesis. The aims of this study were to analyse the changes of serum leptin in newly diagnosed children and adolescents with Type I (insulin-dependent) diabetes mellitus after insulin treatment and to examine the possible impact of ketoacidosis on these changes. Methods. Baseline serum leptin concentrations were measured in 28 newly diagnosed Type I diabetic patients [age 8.75 ± 4.05 years (means ± SD); BMI 15.79 ± 2.47 kg/m2; HbA1 c 11.3 ± 1.9 %] with (n = 18) and without (n = 10) ketoacidosis before commencement of insulin treatment, at the time of diagnosis. Thereafter, during a 4-day course of continuous intravenous insulin injection to gain and maintain euglycaemia, serum leptin concentrations were assessed. Results. Baseline serum leptin concentrations, adjusted to age, BMI, sex and pubertal stage, differed among these patients. There was, however, an increase of leptin in all subjects from 1.37 ± 0.56 ng/ml (mean ± SD) up to 2.97 ± 1.52 ng/ml by 117 % (p < 0.0001) after insulin therapy. On average, peak serum leptin concentration was obtained after 42 h of insulin treatment. Further, there was no difference in the mean increase of serum leptin concentrations in the two groups, namely with and without ketoadicosis, of insulin-dependent diabetic children and adolescents. In addition, there was no correlation between serum leptin concentrations and correction of ketoacidosis during insulin treatment. Conclusions/interpretation. Insulin increases serum leptin, within 1 day, in children and adolescents with newly diagnosed Type I diabetes. Ketoacidosis does not influence this interaction between insulin and leptin. [Diabetologia (1999) 42: 1067–1070]

Impact of different doses of ethinyl oestradiol on reduction of final height in constitutionally tall girls

Fifty-two tall girls were treated for constitutionally tall stature with different ethinyl oestradiol (EE) dosages. They were divided into three different treatment groups: group B (100 μg EE/day;n=11); group C (300 μg;n=25) and group D (500 μg;n=16) and compared with an untreated group A (n=21) matched for age, height, bone age (BA) and height prediction. Using the height prediction method TW II, EE treatment reduced final height compared with the untreated girls in a weak dose-dependent manner, 2.3 cm (100 μg/day), 3.0 cm (300 μg/day), and 3.8 cm (500 μg/day). Such a dose dependency was not found on applying the Bayley-Pineau height prediction method (100 μg/day: 4.1 cm; 300 μg/day: 4.2 cm; 500 μg/day: 4.5 cm). However, there was a striking inverse correlation of the BA at the onset of treatment with the height reduction achieved using the TW II method (r: −0.43;P<0.001). Importantly, girls with a BA below 12 years at the onset of treatment experienced a height reduction of more than 6 cm.The EE dose used in the range of 100–500 μg/day is not crucial for the amount of height reduction in tall girls. In general high dose EE treatment should be given restrictively, and especially so in girls with a BA (TW2 RUS-ZH) above 12.0 years.

Retinoic acid receptor beta and angiopoietin-like protein 1 are involved in the regulation of human androgen biosynthesis

Androgens are essential for sexual development and reproduction. However, androgen regulation in health and disease is poorly understood. We showed that human adrenocortical H295R cells grown under starvation conditions acquire a hyperandrogenic steroid profile with changes in steroid metabolizing enzymes HSD3B2 and CYP17A1 essential for androgen production. Here we studied the regulatory mechanisms underlying androgen production in starved H295R cells. Microarray expression profiling of normal versus starved H295R cells revealed fourteen differentially expressed genes; HSD3B2, HSD3B1, CYP21A2, RARB, ASS1, CFI, ASCL1 and ENC1 play a role in steroid and energy metabolism and ANGPTL1, PLK2, DUSP6, DUSP10 and FREM2 are involved in signal transduction. We discovered two new gene networks around RARB and ANGPTL1, and show how they regulate androgen biosynthesis. Transcription factor RARB stimulated the promoters of genes involved in androgen production (StAR, CYP17A1 and HSD3B2) and enhanced androstenedione production. For HSD3B2 regulation RARB worked in cooperation with Nur77. Secretory protein ANGPTL1 modulated CYP17A1 and DUSP6 expression by inducing ERK1/2 phosphorylation. By contrast, our studies revealed no evidence for hormones or cell cycle involvement in regulating androgen biosynthesis. In summary, these studies establish a firm role for RARB and ANGPTL1 in the regulation of androgen production in H295R cells.

Fetal haemoglobin levels in adult Type 1 (insulin-dependent) diabetic patients

SummaryGlycated haemoglobin levels (HbA1 and HbA1c) are established parameters of long-term glycaemic control in diabetic patients. Depending on the method used, fetal haemoglobin interferes with the assays for glycated haemoglobin. If present in high amounts, fetal haemoglobin may lead to overestimation of glycated haemoglobin levels, and therefore, of average blood glucose concentration in diabetic patients. Glycated (HbA1c) and fetal haemoglobin levels were measured by high pressure liquid chromatography in 60 (30 female) adult Type 1 (insulin-dependent) diabetic patients of Swiss descent, and were compared with levels obtained from 60 normal, non-diabetic control subjects matched for age and sex. Fetal haemoglobin levels were significantly higher in the diabetic patients (0.6±0.1%, mean±SEM; range: 0–3.6%) than in the control subjects (0.4±0.1%, p<0.001). Elevated fetal haemoglobin levels (≥0.6%) were found in 23 of 60 diabetic patients (38%) compared to 9 of 60 control subjects (15%; χ2=8.35, p<0.01). In addition, fetal haemoglobin levels in diabetic patients are weakly correlated with glycated haemoglobin (HbA1c) (r=0.38, p<0.01). Fetal haemoglobin results were confirmed with the alkali denaturation procedure, and by immunocytochemistry using a polyclonal rabbit anti-fetal haemoglobin antibody. A significant proportion of adult patients with Type 1 diabetes has elevated fetal haemoglobin levels. In certain patients this may lead to a substantial over-estimation of glycated haemoglobin levels, and consequently of estimated, average blood glucose levels. The reason for this increased prevalence of elevated fetal haemoglobin remains unclear, but it may be associated with poor glycaemic control.

Intermittent microalbuminuria in children with type 1 diabetes mellitus without clinical evidence of nephropathy

Microalbuminura (MA) was determined in 127 children and adolescents (age 3–21 years) with type 1 (insulin-dependent) diabetes mellitus. Patients with clinical evidence of long-term complications or macroproteinuria were excluded. Urinary albumin excretion was measured in a nocturnal 12-h collection and correlated with the albumin/creatinine ratio of a urine sample freshly voided on the morning immediately following the collection. The patients were divided into group A (n=83, age <16 years, duration of diabetes 1–13 years, mean 4.4) and group B (n=44, age >16 years, duration of diabetes 1–19 years, mean 8.7) and compared with appropriate controls. MA above 15 μg/min was present in 11 of 83 (13.3%) patients in group A and in 7 of 44 (15.9%) in group B. In a repeat urine collection at least 3 months later elevated MA persisted in 1 of 11 (group A) and in 4 of 7 (group B) patients. There was no correlation between increased MA in a 12-h urine collection and the albumin/creatinine ratio in a subsequently voided urine sample. MA was not strictly dependent on age, sex, duration of diabetes, haemoglobin A1, mean arterial blood pressure, plasma creatinine, creatinine clearance or serum beta-2-microglobulin. Further systematic studies and careful follow up are necessary to appraise whether intermittent MA is indeed an early manifestation of incipient kidney disease in children with type 1 diabetes.