High frequency of pathogenic ACAN variants including an intragenic deletion in selected individuals with short stature.

CONTEXT: Defining the underlying etiology of idiopathic short stature (ISS) improves the overall management of an individual. OBJECTIVE: To assess the frequency of pathogenic ACAN variants in selected individuals. DESIGN: The single-center cohort study was conducted at a tertiary university children's hospital. From 51 unrelated patients with ISS, the 16 probands aged between 3 and 18 years (12 females) with advanced bone age and/or autosomal dominant inheritance pattern of short stature were selected for the study. Fifteen family members of ACAN-positive probands were included. Exome sequencing was performed in all probands, and additional copy number variation (CNV) detection was applied in selected probands with a distinct ACAN-associated phenotype. RESULTS: Systematic phenotyping of the study cohort yielded 37.5% (6/16) ACAN-positive probands, with all novel pathogenic variants, including a 6.082 kb large intragenic deletion, detected by array comparative genomic hybridization (array CGH) and exome data analysis. All variants were co-segregated with short stature phenotype, except in one family member with the intragenic deletion who had an unexpected growth pattern within the normal range (-0.5 SDS). One patient presented with otosclerosis, a sign not previously associated with aggrecanopathy. CONCLUSIONS: ACAN pathogenic variants presented a common cause of familial ISS. The selection criteria used in our study were suggested for a personalized approach to genetic testing of the ACAN gene in clinical practice. Our results expanded the number of pathogenic ACAN variants, including the first intragenic deletion, and suggested CNV evaluation in patients with typical clinical features of aggrecanopathy as reasonable. Intra-familial phenotypic variability in growth patterns should be considered.

Hyperinsulinism-hyperammonemia Syndrome in an Infant with Seizures.

Hyperinsulinism-hyperammonemia syndrome (HI/HA) is the second most common form of persistent hyperinsulinemic hypoglycemia of infancy (PHHI). The main clinical characteristics of HI/HA syndrome are repeated episodes of symptomatic hypoglycemia, but not usually severe. Consequently, children with HI/HA syndrome are frequently not recognized in the first months of life. An 8-month-old boy was admitted to a hospital due to hypoglycemia seizures. He also had asymptomatic hyperammonemia with no signs of lethargy or headaches. Genetic testing revealed autosomal dominant syndrome, a mutation in the GLUD1 gene (p.Arg274Cys). The boy started treatment with diazoxide. Subsequent growth and neurological development were normal. Hypoglycemic symptoms in HI/HA syndrome may vary from being non specific to severe. As hypoglycemia could lead to brain injury and impairment of neurological development, timely diagnosis and management are essential. If transient hypoglycemia is ruled out, metabolic disorders must be taken into account.

Circulating levels of miR-122 and nonalcoholic fatty liver disease in pre-pubertal obese children.

OBJECTIVES: The liver-specific miR-122 was proposed as biomarker for NAFLD in adults. Here, we investigated the relationship between miR-122 levels, parameters of liver metabolism and NAFLD in pre-pubertal obese children. METHODS: Parameters of liver metabolism (ALT, AST and GGT) of three European cohorts were included (German cohort [n = 71; age: 11.53 ± 1.29 years; BMI z-score: 2.96 ± 0.64], Italian cohort [n = 45; age: 9.60 ± 2.11 years; BMI z-score: 3.57 ± 1.16], Slovenian cohort [n = 31; age: 7.53 ± 1.47 years; BMI z-score: 3.66 ± 0.88]). MiR-122 levels and CK18 concentrations were measured in fasting blood samples. In the German and Italian cohort, the diagnosis of NAFLD and grading of NAFLD was assessed by ultrasound. RESULTS: NAFLD was diagnosed in n = 50 patients of the German cohort (29.6%) and in n = 29 patients (72.5%) of the Italian cohort. In all three cohorts, miR-122 was positively correlated with ALT and AST as well as with CK18 concentrations. MiR-122 levels were higher in children with NAFLD compared with healthy controls. CONCLUSIONS: MiR-122 levels in pre-pubertal obese children could be a potential biomarker for paediatric NAFLD.

Identification of novel alleles associated with insulin resistance in childhood obesity using pooled-DNA genome-wide association study approach.

BACKGROUND: Recently, we witnessed great progress in the discovery of genetic variants associated with obesity and type 2 diabetes (T2D), especially in adults. Much less is known regarding genetic variants associated with insulin resistance (IR). We hypothesized that novel IR genes could be efficiently detected in a population of obese children and adolescents who may not exhibit comorbidities and other confounding factors. OBJECTIVES: This study aimed to determine whether a genome-wide association study (GWAS), using a DNA-pooling approach, could identify novel genes associated with IR. SUBJECTS: The pooled-DNA GWAS analysis included Slovenian obese children and adolescents with and without IR matched for body mass index, gender and age. A replication study was conducted in another independent cohort with or without IR. METHODS: For the pooled-DNA GWAS, we used HumanOmni5-Quad SNP array (Illumina). Allele frequency distributions were compared with modified t-tests and χ2-tests and ranked using PLINK. Top single nucleotide polymorphisms (SNPs) were validated using individual genotyping by high-resolution melting analysis and TaqMan assay. RESULTS: We identified five top-ranking SNPs from the pooled-DNA GWAS analysis within the ECE1, IL1R2, GNPDA1, HLA-J and PYGB loci. All except SNP rs9261108 (HLA-J locus) were confirmed in the validation phase using individual genotyping. The SNP rs2258617 within PYGB remained statistically significant for both recessive and additive models in both cohorts and in a merged analysis of both cohorts and present the strongest novel candidate gene for IR. CONCLUSION: We report for the first time a pooled-DNA GWAS approach to identify five novel SNPs or genes for IR in a paediatric population. The four loci confirmed in the second validation phase study warrant further studies, especially the strongest SNP rs2258617 within PYGB, and provide targets for further basic research of IR mechanisms and for the development of potential new IR and T2D therapies.

Diabetes Technology-Continuous Subcutaneous Insulin Infusion Therapy and Continuous Glucose Monitoring in Adults: An Endocrine Society Clinical Practice Guideline

"OBJECTIVE: To formulate clinical practice guidelines for the use of continuous glucose monitoring and continuous subcutaneous insulin infusion in adults with diabetes. PARTICIPANTS: The participants include an Endocrine Society-appointed Task Force of seven experts, a methodologist, and a medical writer. The American Association for Clinical Chemistry, the American Association of Diabetes Educators, and the European Society of Endocrinology co-sponsored this guideline. EVIDENCE: The Task Force developed this evidence-based guideline using the Grading of Recommendations, Assessment, Development, and Evaluation system to describe the strength of recommendations and the quality of evidence. The Task Force commissioned one systematic review and used the best available evidence from other published systematic reviews and individual studies. CONSENSUS PROCESS: One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society, the American Association for Clinical Chemistry, the American Association of Diabetes Educators, and the European Society of Endocrinology reviewed and commented on preliminary drafts of these guidelines. CONCLUSIONS: Continuous subcutaneous insulin infusion and continuous glucose monitoring have an important role in the treatment of diabetes. Data from randomized controlled trials are limited on the use of medical devices, but existing studies support the use of diabetes technology for a wide variety of indications. This guideline presents a review of the literature and practice recommendations for appropriate device use."

Routine use of continuous glucose monitoring in 10 501 people with diabetes mellitus.

AIMS: To analyse blood glucose control according to continuous glucose monitoring use in data from the CareLink database, and to identify factors associated with continuation of sensor use during sensor-augmented pump therapy. METHODS: The analysis used data from 10 501 people with Type 1 and 2 diabetes mellitus, of whom 7916 (61.7%) had used glucose sensors for ≥ 15 days during any 6-month period over a 2-year observation period. Data were analysed according to the extent of sensor use ( < 25%, 25-49%, 50-74% and ≥ 75% of the time). Time to discontinuation of sensor use was also analysed in new users of glucose sensors. RESULTS: Compared with patients in the lowest sensor usage group and non-users, the highest glucose sensor usage group had significantly (P < 0.0001) lower mean blood glucose and blood glucose sd, were more likely to achieve a mean blood glucose concentration < 8.6 mmol/l, (odds ratio 1.5, 95% CI 1.3-1.7; P < 0.0001), and had 50% fewer hypoglycaemic (blood glucose concentration < 2.8 mmol/l) episodes. Among new users, sensor use during the first month of therapy was an important predictor of subsequent discontinuation. Lack of full reimbursement was also significantly associated with early discontinuation, whereas measures of glycaemic control were predictive of discontinuation during long-term treatment. CONCLUSIONS: The use of continuous glucose monitoring was significantly associated with reductions in hypoglycaemia and improved metabolic control during insulin pump therapy. Sensor use during the first month was strongly associated with long-term adherence; patient education and training may be helpful in achieving this.

Genetic risk for co-occurrence of type 1 diabetes and celiac disease is modified by HLA-C and killer immunoglobulin-like receptors.

The prevalence of celiac disease (CD) in patients with type 1 diabetes (T1D) has been reported to be 5-7 times higher than in the general population. Risk factors for co-occurrence of both diseases have not been entirely established. The aim of our study was to analyze possible impact of human leukocyte antigen (HLA) class I and killer cell immunoglobulin-like receptors (KIRs) on the co-occurrence of T1D and CD. We analyzed 67 patients with T1D, 68 patients with CD, 69 patients with both diseases (T1D+CD) and 130 controls. Statistical analysis was based on two tailed Fisher exact test with corrections for multiple testing. After stratification by DR3-DQ2, an association of HLA class I part of the COX haplotype (A1-B8-Cw7-DR3-DQ2) was not observed with each of the studied diseases separately, but it could be shown in case of the co-occurrence of T1D and CD. Only in the group of patients with coexisting diseases, the presence of HLA-C*07 (P = 8.65×10(-3) ) and HLA-B*08 (P = 0.03) but not HLA-A*01 increased the succeptibility. Our current data indicated that C*07, contributing C1 ligand (Pc = 3.67×10(-5) ) rather than B*08, that possesses no KIR ligand, could have an impact on the innate immunity rout of this susceptibility. The significant combination of C1-KIR2DL3 (Pc = 1.97×10(-4) ) observed in patients with coexisting diseases supports this hypotesis. Interestingly, no association was observed when C1 in combination with its stronger inhibitory receptor KIR2DL2 was investigated. Predominantly, weak inhibition in patients with coexisting T1D and CD could lead to a natural killer cell response, making them vulnerable for developing more than one autoimmune disease.

Impact of continuous glucose monitoring on quality of life, treatment satisfaction, and use of medical care resources: analyses from the SWITCH study.

To investigate the impact of continuous glucose monitoring (CGM) on health-related quality of life (HRQOL), treatment satisfaction (TS) medical resource use, and indirect costs in the SWITCH study. SWITCH was a multicentre, randomized, crossover study. Patients with type 1 diabetes (n = 153) using continuous subcutaneous insulin infusion (CSII) were randomized to a 12 month sensor-On/Off or sensor-Off/On sequence (6 months each treatment), with a 4-month washout between periods. HRQOL in children and TS in adults were measured using validated questionnaires. Medical resource utilization data were collected. In adults, TS was significantly higher in the sensor-On arm, and there were significant improvements in ratings for treatment convenience and flexibility. There were no clinically significant differences in children's HRQOL or parents' proxy ratings. The incidence of severe hypoglycaemia, unscheduled visits, or diabetes-related hospitalizations did not differ significantly between the two arms. Adult patients made fewer telephone consultations during the sensor-On arm; children's caregivers made similar numbers of telephone consultations during both arms, and calls were on average only 3 min longer during the sensor-On arm. Regarding indirect costs, children with >70 % sensor usage missed fewer school days, compared with the sensor-Off arm (P = 0.0046) but there was no significant difference in the adults days of work off. The addition of CGM to CSII resulted in better metabolic control without imposing an additional burden on the patient or increased medical resource use, and offered the potential for cost offsets.

Fasting and meal-stimulated residual beta cell function is positively associated with serum concentrations of proinflammatory cytokines and negatively associated with anti-inflammatory and regulatory cytokines in patients with longer term type 1 diabetes.

AIMS/HYPOTHESIS: Cytokines may promote or inhibit disease progression in type 1 diabetes. We investigated whether systemic proinflammatory, anti-inflammatory and regulatory cytokines associated differently with fasting and meal-stimulated beta cell function in patients with longer term type 1 diabetes. METHODS: The beta cell function of 118 patients with type 1 diabetes of duration of 0.75-4.97 years was tested using a standardised liquid mixed meal test (MMT). Serum samples obtained at -5 to 120 min were analysed by multiplex bead-based technology for proinflammatory (IL-6, TNF-α), anti-inflammatory (IL-1 receptor antagonist [IL-1RA]) and regulatory (IL-10, TGF-ß1-3) cytokines, and by standard procedures for C-peptide. Differences in beta cell function between patient groups were assessed using stepwise multiple regression analysis adjusting for sex, age, duration of diabetes, BMI, HbA1c and fasting blood glucose. RESULTS: High fasting systemic concentrations of the proinflammatory cytokines IL-6 and TNF-α were associated with increased fasting and stimulated C-peptide concentrations even after adjustment for confounders (p < 0.03). Interestingly, increased concentrations of anti-inflammatory/regulatory IL-1RA, IL-10, TGF-ß1 and TGF-ß2 were associated with lower fasting and stimulated C-peptide levels (p < 0.04), losing significance on adjustment for anthropometric variables. During the MMT, circulating concentrations of IL-6 and TNF-α increased (p < 0.001) while those of IL-10 and TGF-ß1 decreased (p < 0.02) and IL-1RA and TGF-ß2 remained unchanged. CONCLUSIONS/INTERPRETATION: The association between better preserved beta cell function in longer term type 1 diabetes and increased systemic proinflammatory cytokines and decreased anti-inflammatory and regulatory cytokines is suggestive of ongoing inflammatory disease activity that might be perpetuated by the remaining beta cells. These findings should be considered when designing immune intervention studies aimed at patients with longer term type 1 diabetes and residual beta cell function.

Anti-cytokine autoantibodies suggest pathogenetic links with autoimmune regulator deficiency in humans and mice.

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is a recessive disorder resulting from mutations in the autoimmune regulator (AIRE). The patients' autoantibodies recognize not only multiple organ-specific targets, but also many type I interferons (IFNs) and most T helper type 17 (Th17) cell-associated cytokines, whose biological actions they neutralize in vitro. These anti-cytokine autoantibodies are highly disease-specific: otherwise, they have been found only in patients with thymomas, tumours of thymic epithelial cells that fail to express AIRE. Moreover, autoantibodies against Th17 cell-associated cytokines correlate with chronic mucocutaneous candidiasis in both syndromes. Here, we demonstrate that the immunoglobulin (Ig)Gs but not the IgAs in APECED sera are responsible for neutralizing IFN-ω, IFN-α2a, interleukin (IL)-17A and IL-22. Their dominant subclasses proved to be IgG1 and, surprisingly, IgG4 without IgE, possibly implicating regulatory T cell responses and/or epithelia in their initiation in these AIRE-deficiency states. The epitopes on IL-22 and IFN-α2a appeared mainly conformational. We also found mainly IgG1 neutralizing autoantibodies to IL-17A in aged AIRE-deficient BALB/c mice - the first report of any target shared by these human and murine AIRE-deficiency states. We conclude that autoimmunization against cytokines in AIRE deficiency is not simply a mere side effect of chronic mucosal Candida infection, but appears to be related more closely to disease initiation.

The use and efficacy of continuous glucose monitoring in type 1 diabetes treated with insulin pump therapy: a randomised controlled trial.

AIMS/HYPOTHESIS: The aim of this multicentre, randomised, controlled crossover study was to determine the efficacy of adding continuous glucose monitoring (CGM) to insulin pump therapy (CSII) in type 1 diabetes. METHODS: Children and adults (n = 153) on CSII with HbA(1c) 7.5-9.5% (58.5-80.3 mmol/mol) were randomised to (CGM) a Sensor On or Sensor Off arm for 6 months. After 4 months' washout, participants crossed over to the other arm for 6 months. Paediatric and adult participants were separately electronically randomised through the case report form according to a predefined randomisation sequence in eight secondary and tertiary centres. The primary outcome was the difference in HbA(1c) levels between arms after 6 months. RESULTS: Seventy-seven participants were randomised to the On/Off sequence and 76 to the Off/On sequence; all were included in the primary analysis. The mean difference in HbA(1c) was -0.43% (-4.74 mmol/mol) in favour of the Sensor On arm (8.04% [64.34 mmol/mol] vs 8.47% [69.08 mmol/mol]; 95% CI -0.32%, -0.55% [-3.50, -6.01 mmol/mol]; p < 0.001). Following cessation of glucose sensing, HbA(1c) reverted to baseline levels. Less time was spent with sensor glucose <3.9 mmol/l during the Sensor On arm than in the Sensor Off arm (19 vs 31 min/day; p = 0.009). The mean number of daily boluses increased in the Sensor On arm (6.8 ± 2.5 vs 5.8 ± 1.9, p < 0.0001), together with the frequency of use of the temporary basal rate (0.75 ± 1.11 vs 0.26 ± 0.47, p < 0.0001) and manual insulin suspend (0.91 ± 1.25 vs 0.70 ± 0.75, p < 0.018) functions. Four vs two events of severe hypoglycaemia occurred in the Sensor On and Sensor Off arm, respectively (p = 0.40). CONCLUSIONS/INTERPRETATION: Continuous glucose monitoring was associated with decreased HbA(1c) levels and time spent in hypoglycaemia in individuals with type 1 diabetes using CSII. More frequent self-adjustments of insulin therapy may have contributed to these effects.

Continuous glucose monitoring in 2010.

After the initial positive data several recent randomised controlled trials offer more firm evidence supporting the efficacy and safety of real-time continuous glucose monitoring (CGM) in type 1 diabetes (T1D). Integrating CGM with insulin pumps offers additional benefit. Improved metabolic control with significant lowering of glycated haemoglobin along with other parameters of glycaemia and without a concomitant increase in hypoglycaemia is demonstrated in all age groups, including children and adolescents. Reducing hypoglycaemia with CGM in well-controlled individuals with T1D remains to be demonstrated; however, evidence for reducing hypoglycaemia in critically ill patients seems convincing. Several important aspects of type 2 diabetes (T2D) were recently addressed by professional CGM. Adding predictive algorithms to CGM may considerably improve its efficacy and lead the way towards the closed loop.

An influence of HLA-A, B, DR, DQ, and MICA on the occurrence of Celiac disease in patients with type 1 diabetes.

Celiac disease (CD) is more common in individuals with insulin dependent diabetes mellitus (T1D) than in the general population. HLA class II molecules DQ8 (DQB1*0302-DQA1*0301) and DQ2 (DQB1*0201-DQA1*0501) have been identified as key genetic risk factors in both diseases. While DQ8 conveys a higher risk for T1D, DQ2 is more frequent in CD. Less is known about the contribution of HLA class I. The gut immune system has been implicated in the pathogenesis of both diseases. The MICA, which is mainly expressed in the gastrointestinal epithelium and recognized by gammadeltaT lymphocytes and natural killer (NK) cells via the NKG2D, might play a role. The aim of our study was to identify possible HLA class I and MICA alleles and conserved extended haplotypes as risk factors for the development of CD in T1D. Three groups consisting of 37 individuals with T1D and CD, 67 individuals with only T1D and 70 controls were analyzed. HLA class I and MICA alleles were determined using Luminex technology. An occurrence of CD in individuals with T1D was most significantly associated with B*08 (P = 7.3 x 10(-13)), contributing more than any of the HLA class II alleles (DRB1*0301, P = 5.00 x 10(-10); DQB1*0201, P = 7.65 x 10(-8)). Moreover, the association with CD became stronger when B*08(B*08-DQA*0501-DQB1*0201-DRB1*0301, P = 5.07 x 10(-12)) was present in the DRB1*0301-DQB1*0201-DQA1*0501 (P = 5.00 x 10(-10)) extended haplotype. We suggest a combined influence of alleles present in the MICA*008-B*08-A1-DR3-DQ2 extended haplotype on the development of CD in Slovenian individuals with T1D, where B*08 or/and a gene located close to it may play an important role, independently of HLA class II.

Continuous glucose monitoring.

Real-time continuous glucose monitoring (RT-CGM) has the potential to revolutionise the care and treatment of individuals with type 1 diabetes (T1D). During the past three years, several devices to measure the interstitial fluid intermittently or continuously have been developed and approved as an adjunct to blood glucose monitoring for use in individuals with T1D. Original studies using these earlier devices showed promise in lowering HbA1c in selected individuals with suboptimal control (1). The first randomised controlled trial with a subcutaneous continuous sensor demonstrated a significant decrease in HbA1c in adult and paediatric patients with poor metabolic control using the RT-CGM device continuously for 3 months compared with the self-monitoring of blood glucose (SMBG) control group (2). Recent randomised controlled trials clearly demonstrated that RT-CGM can significantly reduce HbA1c. Additionally, retrospective use of CGM data can positively affect metabolic control in both type 1 and type 2 diabetes.

Establishing glycaemic control with continuous subcutaneous insulin infusion in children and adolescents with type 1 diabetes: experience of the PedPump Study in 17 countries.

AIMS/HYPOTHESIS: To assess the use of paediatric continuous subcutaneous infusion (CSII) under real-life conditions by analysing data recorded for up to 90 days and relating them to outcome. METHODS: Pump programming data from patients aged 0-18 years treated with CSII in 30 centres from 16 European countries and Israel were recorded during routine clinical visits. HbA(1c) was measured centrally. RESULTS: A total of 1,041 patients (age: 11.8 +/- 4.2 years; diabetes duration: 6.0 +/- 3.6 years; average CSII duration: 2.0 +/- 1.3 years; HbA(1c): 8.0 +/- 1.3% [means +/- SD]) participated. Glycaemic control was better in preschool (n = 142; 7.5 +/- 0.9%) and pre-adolescent (6-11 years, n = 321; 7.7 +/- 1.0%) children than in adolescent patients (12-18 years, n = 578; 8.3 +/- 1.4%). There was a significant negative correlation between HbA(1c) and daily bolus number, but not between HbA(1c) and total daily insulin dose. The use of <6.7 daily boluses was a significant predictor of an HbA(1c) level >7.5%. The incidence of severe hypoglycaemia and ketoacidosis was 6.63 and 6.26 events per 100 patient-years, respectively. CONCLUSIONS/INTERPRETATION: This large paediatric survey of CSII shows that glycaemic targets can be frequently achieved, particularly in young children, and the incidence of acute complications is low. Adequate substitution of basal and prandial insulin is associated with a better HbA(1c).

Goiter prevalence and urinary iodine concentration in Slovenian adolescents.

CONTEXT: Slovenian school-age children are, as are more than half of European school-age children, still considered to be iodine deficient. In 1999, supplementation of salt was increased from 10 to 25 mg of KI/kg of salt. OBJECTIVE: The objective of our study was to determine the success of this intervention. DESIGN AND PATIENTS: Twelve hundred sixty-four girls (mean age +/- SD: 15.7 +/- 0.6 years) and 1200 boys (15.8 +/- 0.8 years) representing 10% of all 15-year-old Slovenian adolescents were studied. Thyroid size was estimated by clinical examination in all subjects and by ultrasound when enlarged thyroid was suspected. Thyroid volume was also determined by ultrasound in 108 random iodine-sufficient adolescents. In addition, urinary iodine concentration was determined in all subjects. RESULTS: Enlarged thyroid was determined by clinical examination and ultrasound in 0.9% of all subjects. In randomly selected iodine-sufficient subjects, enlarged thyroid was determined in 4.6%. Median urinary iodine concentration for the population was 140 microg/L. In all regions it was greater than or equal to 100 microg/L. Values less than 50 microg/L were determined in 2.5% of all subjects. CONCLUSIONS: Slovenian adolescents are iodine sufficient and the prevalence of goiter is low, indicating that increased KI supplementation of salt in 1999 was successful.

Mutational spectrum of steroid 21-hydroxylase and the genotype-phenotype association in Middle European patients with congenital adrenal hyperplasia.

OBJECTIVE: To analyze the mutational spectrum of steroid 21-hydroxylase (CYP21) and the genotype- phenotype correlation in patients with congenital adrenal hyperplasia (CAH) registered in the Middle European Society for Pediatric Endocrinology CAH database, and to design a reliable and rational approach for CYP21 mutation detection in Middle European populations. DESIGN AND METHODS: Molecular analysis of the CYP21 gene was performed in 432 CAH patients and 298 family members. Low-resolution genotyping was performed to detect the eight most common point mutations. High-resolution genotyping, including Southern blotting and sequencing was performed to detect CYP21 gene deletions, conversions, point mutations or other sequence changes. RESULTS: CYP21 gene deletion and In2 and Ile172Asn mutation accounted for 72.7% of the affected alleles in the whole study group. A good genotype-phenotype correlation was observed, with the exception of Ile172Asn and Pro30Leu mutations. In 37% of patients low resolution genotyping could not identify the causative mutation or distinguish homozygosity from hemizygosity. Using high-resolution genotyping, the causative mutations could be identified in 341 out of 348 analyzed patients. A novel mutation Gln315Stop was found in one simple virilising CAH (SV-CAH) patient from Austria. In the remaining seven patients polymorphisms were identified as the leading sequence alteration. The presence of elevated basal and ACTH-stimulated 17-hydroxyprogesterone, premature pubarche, advanced bone age and clitoral hypertrophy directly implicated Asn493Ser polymorphism in the manifestation of nonclassical- (NC) and even SV-CAH. CONCLUSIONS: By genotyping for the most common point mutations, CYP21 gene deletion/conversion and the 8 bp deletion in exon 3, it should be possible to identify the mutation in 94-99% of the diseased alleles in any investigated Middle European population. In patients with a mild form of the disease and no detectable mutation CYP21 gene polymorphisms should be considered as a plausible disease-causing mutation.

Motor activity during asymptomatic nocturnal hypoglycemia in adolescents with type 1 diabetes mellitus.

Nocturnal hypoglycemia is reported in 13%-56% of adolescents with type 1 diabetes mellitus. It may be asymptomatic in more than 50% of patients. No noninvasive method for detecting asymptomatic nocturnal hypoglycemia (ANH) has so far proven successful. The aim of the present study was to evaluate quantitative changes of motor activity by actigraphy during episodes of ANH in adolescents with type 1 diabetes mellitus. A total of 18 patients aged 10-16 years with a history of ANH were investigated. Blood was sampled at half-hourly intervals between 22.30 and 06.00 hours with a micropump, and an actigraph was fastened to the right wrist. Blood glucose concentrations were measured and compared to motor activity. Nocturnal hypoglycemia was recorded in 10 patients (55%), with blood glucose during periods of hypoglycemia of 3.00+0.17 mmol/l (range, 1.2-3.4 mmol/l), and duration of hypoglycemia of 1.95+1.34 hours (range, 0.5-5.0 hours). All periods of hypoglycemia were clinically asymptomatic. Regression analysis revealed a statistically significant linear correlation ( p=0.03) between blood glucose concentration and the respective 30-min activity counts. Activity counts in patients with nocturnal hypoglycemia were significantly (ANOVA, p<0.02) higher than in patients with normoglycemia. We conclude that low blood glucose was significantly correlated with an increase in motor activity as detected by actigraphy. This implies the possibility of noninvasive screening of asymptomatic nocturnal hypoglycemia.

Mutational spectrum of congenital adrenal hyperplasia in Slovenian patients: a novel Ala15Thr mutation and Pro30Leu within a larger gene conversion associated with a severe form of the disease.

OBJECTIVE: To analyse the mutational spectrum, the associated haplotypes and the genotype-phenotype correlation, and to design a reliable and rational approach for CYP21 mutation detection in Slovenian congenital adrenal hyperplasia (CAH) patients. DESIGN: Molecular analysis of the CYP21 gene was performed in 36 CAH patients and 79 family members. METHODS: Southern blotting, sequence-specific PCR amplification (PCR-SSP), sequence-specific oligonucleotide hybridisation (PCR-SSO) and sequencing were used to detect CYP21 gene deletions, conversions and point mutations. RESULTS: CYP21 gene deletion was the most frequent mutation (36.4%). Large gene conversions detectable only by Southern blotting represented 12.1%, and gene conversions involving the promoter region represented 7.6% of the mutated alleles. The most frequent point mutations were: intron 2 splice mutation 16.7%, Ile172Asn mutation 7.6%, Gln318Stop 7.5% and Pro30Leu 12.2% of alleles. A correlation between the genotype and the clinical phenotype similar to those described for large populations was observed. The finding of Pro30Leu mutation linked to a gene conversion could explain the simple virilising (SV) phenotype in compound heterozygotes for the Pro30Leu and a severe mutation. In two siblings with a salt wasting form of CAH (SW-CAH), a novel mutation Ala15Thr was found on the allele characterised by Pro30Leu mutation and gene conversion involving the promoter region. CONCLUSIONS: Our genotyping approach allowed reliable diagnosis of CAH in the Slovenian population. The high frequency of CYP21 gene aberrations on Pro30Leu positive alleles justified systematic searching for a gene conversion in the promoter region using the PCR-SSP reaction.

The HLA-DRB, -DQB polymorphism and anti-insulin antibody response in Slovenian patients with type 1 diabetes.

A combination of specific HLA class II antigens and the presence of type 1 diabetes (T1D)-related antibodies has a high positive predictive value for T1D but low sensitivity. The aim of the present study was to determine the frequencies of HLA-DRB-DQB deduced haplotypes associated with susceptibility and protection in Slovenian patients with established T1D, to evaluate the relationship between the HLA-DRB1-QBP-DQB1 haplotypes and the presence of insulin autoantibodies (IAA) and glutamic acid decarboxylase antibodies (GADA), and to access the possible impact of polymorphic QBP promoters on this relationship. A cohort of 135 patients with T1D (age 17.5 +/- 7.0 years, duration of T1D 9.14 +/- 6.3 years) was investigated. HLA-DRB1 and DQB1 alleles were typed using the polymerase chain reaction (PCR)-reverse line blot method. QBP promoter region alleles were determined using PCR-sequence-specific oligonucleotide hybridization (SSO) and PCR-sequence-specific primers (SSP). IAA and GADA antibodies were determined by enzyme-linked immunosorbent assay (ELISA). The chi-square test with Yates' correction was used for statistical analysis. Deduced haplotypes DRB1*0301-DQB1*0201 (P = 0.0001, OR = 3.4), DRB1*0401-DQB1*0302 (P = 0.0001, OR = 29.8), and DRB1*0402-DQB1*0302 (P = 0.008, OR = 4.7) were significantly more common, and DRB1*1501-DQB1*0602 (P = 0.0001, OR = 0.03) significantly less common in the investigated cohort than in a Slovenian control group. The highest risk and the strongest protective HLA-DR-DQ haplotypes found in Slovenian patients with T1D did not differ from those found in other Caucasian populations. While the DRB1*0301-QBP2.1-DQB1*0201 haplotype, where QBP2.1 did not help to further distinguish DQB1*0201-possessing haplotypes in IAA-positive and IAA-negative patients, was strongly associated with the presence of IAA, the DRB1*0101-QBP5.12-DQB1*0501 haplotype, although not protective compared to the control population, was associated with an absence of IAA in the investigated cohort. It is suggested that there may be a combined influence of the QBP5.12 promoter and the DQB1*0501 functional molecule on reduced IAA production.