Academic skills in children with early-onset type 1 diabetes: the effects of diabetes-related risk factors.

AIM: The study aimed to assess the effects of diabetes-related risk factors, especially severe hypoglycaemia,on the academic skills of children with early-onset type 1 diabetes mellitus (T1DM). METHOD: The study comprised 63 children with T1DM (31 females, 32 males; mean age 9 y 11 mo,SD 4 mo) and 92 comparison children without diabetes (40 females, 52 males;mean age 9 y 9 mo,SD 3 mo). Children were included if T1DM had been diagnosed before the age of 5 years and if they were aged between 9 and 10 years at the time of study. Children were not included if their native language was not Finnish and if they had a diagnosed neurological disorder that affected their cognitive development. Among the T1DM group, 37 had and 26 had not experienced severe hypoglycaemia and 26 had avoided severe hypoglycaemia. Severe hypoglycaemia, diabetic ketoacidosis(DKA), and glycaemic control were used as T1DM-related factors. Task performance in reading, spelling, and mathematics was compared among the three groups, and the effects of the T1DM-related factors were analysed with general linear models. RESULTS: The groups with (p<0.001) and without (p=0.001) severe hypoglycaemia demonstrated a poorer performance than the comparison group in spelling, and the group without severe hypoglycaemia showed a poorer performance than the comparison group in mathematics (p=0.003).Severe hypoglycaemia, DKA, and recent glycaemic control were not associated with poorer skills,but poorer first-year glycaemic control was associated with poorer spelling (p=0.013). INTERPRETATION: An early onset of T1DM can increase the risk of learning problems, independently of the history of severe hypoglycaemia or DKA. Poorer glycaemic control after the first year of T1DM is associated with a poorer acquisition of academic skills indicating the effect of the timing of metabolic aberrations on cognitive development.

Aminoglycoside pretreatment partially restores the function of truncated V(2) vasopressin receptors found in patients with nephrogenic diabetes insipidus.

By screening patients with X-linked nephrogenic diabetes insipidus (NDI) for mutations within the V(2) vasopressin receptor (AVPR2) gene, we have identified six novel and two recurrent mutations. Additionally, one patient revealed a genomic deletion of 3.2 kb encompassing most of the AVPR2 gene and the last exon/3'-region of C1 gene, which is in close proximity to the AVPR2 locus. In-depth characterization of the mutant AVPR2s by a combination of functional and immunological techniques allowed to gain further insight into molecular mechanisms leading to the receptor dysfunction. Aiming at the functional reconstitution of mutant G protein-coupled receptors, several strategies of potential therapeutic usefulness have been tested. Because the functional rescue of truncated receptors is most challenging, we addressed this issue by applying an aminoglycoside approach. Here, we demonstrate that the misreading capacity of the aminoglycoside antibiotic geneticin was sufficient to restore function of mutant AVPR2s harboring premature stop codons in an in vitro expression system.