Further delineation of genotype-phenotype correlation in homozygous 2p21 deletion syndromes: first description of patients without cystinuria.

Homozygous contiguous gene deletion syndromes are rare. On 2p21, however, several overlapping homozygous gene deletion syndromes have been described, all presenting with cystinuria but otherwise distinct phenotypes. Hypotonia-cystinuria syndrome (HCS, OMIM606407) is characterized by infantile hypotonia, poor feeding, and growth hormone deficiency. Affected individuals carry homozygous deletions including the cystinuria gene SLC3A1 and the adjacent PREPL gene. Larger homozygous deletions in this region encompassing the PPM1B, SLC3A1, PREPL, and C2orf34 (CAMKMT) genes result in a more severe phenotype, the 2p21 deletion syndrome. A phenotype intermediate to HCS and the 2p21 deletion syndrome is termed atypical HCS and is caused by deletion of SLC3A1, PREPL, and C2orf34 (CAMKMT). Using high resolution SNP array molecular karyotyping we identified two siblings with a homozygous deletion of 83 kb partially encompassing the genes PREPL and C2orf34 (CAMKMT), but not the SLC3A1 gene. The affected siblings display a recognizable phenotype which is similar to atypical HCS with regard to growth failure and neuro-muscular features, but is characterized by lack of cystinuria. The patients also exhibit features which have not been reported to date such as cleft palate and genital abnormalities. In conclusion, we report the first patients with a homozygous 2p21 deletion syndrome without cystinuria and further delineate the complex genotype-phenotype correlations of homozygous microdeletion syndromes of this region.

Confidence-driven weighted retraining for predicting safety-critical failures in autonomous driving systems.

Safe handling of hazardous driving situations is a task of high practical relevance for building reliable and trustworthy cyber-physical systems such as autonomous driving systems. This task necessitates an accurate prediction system of the vehicle's confidence to prevent potentially harmful system failures on the occurrence of unpredictable conditions that make it less safe to drive. In this paper, we discuss the challenges of adapting a misbehavior predictor with knowledge mined during the execution of the main system. Then, we present a framework for the continual learning of misbehavior predictors, which records in-field behavioral data to determine what data are appropriate for adaptation. Our framework guides adaptive retraining using a novel combination of in-field confidence metric selection and reconstruction error-based weighing. We evaluate our framework to improve a misbehavior predictor from the literature on the Udacity simulator for self-driving cars. Our results show that our framework can reduce the false positive rate by a large margin and can adapt to nominal behavior drifts while maintaining the original capability to predict failures up to several seconds in advance.

Regulation of fetal growth: consequences and impact of being born small.

The first trimester of pregnancy is the time during which organogenesis takes place and tissue patterns and organ systems are established. In the second trimester the fetus undergoes major cellular adaptation and an increase in body size, and in the third trimester organ systems mature ready for extrauterine life. In addition, during that very last period of intrauterine life there is a significant increase in body weight. In contrast to the postnatal endocrine control of growth, where the principal hormones directly influencing growth are growth hormone (GH) and the insulin-like growth factors (IGFs) via the GH-IGF axis, fetal growth throughout gestation is constrained by maternal factors and placental function and is coordinated by growth factors. In general, growth disorders only become apparent postnatally, but they may well be related to fetal life. Thus, fetal growth always needs to be considered in the overall picture of human growth as well as in its metabolic development.

Metabolic control of type 1 diabetic patients followed at the University Children's Hospital in Berne: have we reached the goal?

QUESTION UNDER STUDY: In type 1 diabetes (T1DM), a good metabolic control is important to reduce and/or postpone complications. Guidelines regarding how to achieve this goal are published by the American Diabetes Association (ADA) and the International Society of Paediatric and Adolescence Diabetes (ISPAD). The aims of this study were to determine the current level of metabolic control in T1DM patients on different treatment regimens, followed at the diabetes outpatient unit of the University Children's Hospital Bern, Switzerland, and to compare it with both the reported data from ten years ago (1998) and with the current guidelines of the ADA and ISPAD. METHODS: This was an observational, cross-sectional study and involved assessment of HbA1c levels as a surrogate marker of the metabolic control in all patients seen during a regular four month interval at our outpatient clinic. RESULTS: A total of 152 patients (88m, 64f) were recorded. 43.4% (n = 66) were conventionally treated (insulin: twice-daily, three-dose treatment), whereas 56.6% (n = 86) were on a multiple injection treatment (e.g. functional insulin treatment and/or insulin pump). Actual overall HbA1c values, expressed as medians (25th/75th centiles), were 7.6% (7.0/8.3) compared to 7.9% (7.3/8.6) in 1998 (p <0.01). In younger, prepubertal children the HbA1c value recorded was 7.4% (6.9/8.1), and 7.7% (7.2/8.5) in adolescents. Interestingly, no significant difference was observed between HbA1c levels of conventionally versus intensively treated patients. CONCLUSIONS: With current treatment strategies, glycaemic control of T1DM children and adolescents improved significantly (p <0.01) between 1998 and 2008, although only a minority of the subjects reached the ISPAD goals.

A comparative phenotypic study of kallmann syndrome patients carrying monoallelic and biallelic mutations in the prokineticin 2 or prokineticin receptor 2 genes.

CONTEXT: Both biallelic and monoallelic mutations in PROK2 or PROKR2 have been found in Kallmann syndrome (KS). OBJECTIVE: The objective of the study was to compare the phenotypes of KS patients harboring monoallelic and biallelic mutations in these genes. DESIGN AND PATIENTS: We studied clinical and endocrine features that reflect the functioning of the pituitary-gonadal axis, and the nonreproductive phenotype, in 55 adult KS patients (42 men and 13 women), of whom 41 had monoallelic mutations and 14 biallelic mutations in PROK2 or PROKR2. RESULTS: Biallelic mutations were associated with more frequent cryptorchidism (70% vs. 34%, P < 0.05) and microphallus (90% vs. 28%, P < 0.001) and lower mean testicular volume (1.2 +/- 0.4 vs. 4.5 +/- 6.0 ml; P < 0.01) in male patients. Likewise, the testosterone level as well as the basal FSH level and peak LH level under GnRH-stimulation were lower in males with biallelic mutations (0.2 +/- 0.1 vs. 0.7 +/- 0.8 ng/ml; P = 0.05, 0.3 +/- 0.1 vs. 1.8 +/- 3.0 IU/liter; P < 0.05, and 0.8 +/- 0.8 vs. 5.2 +/- 5.5 IU/liter; P < 0.05, respectively). Nonreproductive, nonolfactory anomalies were rare in both sexes and were never found in patients with biallelic mutations. The mean body mass index of the patients (23.9 +/- 4.2 kg/m(2) in males and 26.3 +/- 6.6 kg/m(2) in females) did not differ significantly from that of gender-, age-, and treatment-matched KS individuals who did not carry a mutation in PROK2 or PROKR2. Finally, circadian cortisol levels evaluated in five patients, including one with biallelic PROKR2 mutations, were normal in all cases. CONCLUSION: Male patients carrying biallelic mutations in PROK2 or PROKR2 have a less variable and on average a more severe reproductive phenotype than patients carrying monoallelic mutations in these genes. Nonreproductive, nonolfactory clinical anomalies associated with KS seem to be restricted to patients with monoallelic mutations.