<i>GRIN2A</i>-related disorders:genotype and functional consequence predict phenotype

Alterations of the N-methyl-d-aspartate receptor (NMDAR) subunit GluN2A, encoded by GRIN2A, have been associated with a spectrum of neurodevelopmental disorders with prominent speech-related features, and epilepsy. We performed a comprehensive assessment of phenotypes with a standardized questionnaire in 92 previously unreported individuals with GRIN2A-related disorders. Applying the criteria of the American College of Medical Genetics and Genomics to all published variants yielded 156 additional cases with pathogenic or likely pathogenic variants in GRIN2A, resulting in a total of 248 individuals. The phenotypic spectrum ranged from normal or near-normal development with mild epilepsy and speech delay/apraxia to severe developmental and epileptic encephalopathy, often within the epilepsy-aphasia spectrum. We found that pathogenic missense variants in transmembrane and linker domains (misTMD+Linker) were associated with severe developmental phenotypes, whereas missense variants within amino terminal or ligand-binding domains (misATD+LBD) and null variants led to less severe developmental phenotypes, which we confirmed in a discovery (P = 10-6) as well as validation cohort (P = 0.0003). Other phenotypes such as MRI abnormalities and epilepsy types were also significantly different between the two groups. Notably, this was paralleled by electrophysiology data, where misTMD+Linker predominantly led to NMDAR gain-of-function, while misATD+LBD exclusively caused NMDAR loss-of-function. With respect to null variants, we show that Grin2a+/- cortical rat neurons also had reduced NMDAR function and there was no evidence of previously postulated compensatory overexpression of GluN2B. We demonstrate that null variants and misATD+LBD of GRIN2A do not only share the same clinical spectrum (i.e. milder phenotypes), but also result in similar electrophysiological consequences (loss-of-function) opposing those of misTMD+Linker (severe phenotypes; predominantly gain-of-function). This new pathomechanistic model may ultimately help in predicting phenotype severity as well as eligibility for potential precision medicine approaches in GRIN2A-related disorders

Intravenous paracetamol overdose in a paediatric patient

BACKGROUND: Paracetamol is a widely used drug in children. In therapeutic doses, paracetamol has an excellent safety profile. Since the introduction of the intravenous form in 2004, only three reports of accidental overdose in children have been published. The low number probably is due to underreporting. CASE DESCRIPTION: A two weeks old boy received a single intravenous dose of 90 mg/kg paracetamol - nearly a tenfold overdose. The child was not treated with acetylcysteine and developed no hepatic impairment. CONCLUSION: Intravenous paracetamol is a potentially dangerous drug. INTRAVENOUS: acetylcysteine is widely recognized as the antidote. The treatment indication is still based on an adult nomogram. Children are less at risk for complications, but this should be monitored. Acetylcysteine is effective and safe in the management of paracetamol-induced hepatotoxicity, but mild adverse drug reactions are frequently reported

Intravenous paracetamol overdose in a paediatric patient

BACKGROUND: Paracetamol is a widely used drug in children. In therapeutic doses, paracetamol has an excellent safety profile. Since the introduction of the intravenous form in 2004, only three reports of accidental overdose in children have been published. The low number probably is due to underreporting. CASE DESCRIPTION: A two weeks old boy received a single intravenous dose of 90 mg/kg paracetamol - nearly a tenfold overdose. The child was not treated with acetylcysteine and developed no hepatic impairment. CONCLUSION: Intravenous paracetamol is a potentially dangerous drug. INTRAVENOUS: acetylcysteine is widely recognized as the antidote. The treatment indication is still based on an adult nomogram. Children are less at risk for complications, but this should be monitored. Acetylcysteine is effective and safe in the management of paracetamol-induced hepatotoxicity, but mild adverse drug reactions are frequently reported

Beneficial effects of growth hormone treatment on cognition in children with Prader-Willi syndrome: a randomized controlled trial and longitudinal study.

Item does not contain fulltextBACKGROUND: Knowledge about the effects of GH treatment on cognitive functioning in children with Prader-Willi syndrome (PWS) is limited. METHODS: Fifty prepubertal children aged 3.5 to 14 yr were studied in a randomized controlled GH trial during 2 yr, followed by a longitudinal study during 4 yr of GH treatment. Cognitive functioning was measured biennially by short forms of the WPPSI-R or WISC-R, depending on age. Total IQ (TIQ) score was estimated based on two subtest scores. RESULTS: During the randomized controlled trial, mean sd scores of all subtests and mean TIQ score remained similar compared to baseline in GH-treated children with PWS, whereas in untreated controls mean subtest sd scores and mean TIQ score decreased and became lower compared to baseline. This decline was significant for the Similarities (P = 0.04) and Vocabulary (P = 0.03) subtests. After 4 yr of GH treatment, mean sd scores on the Similarities and Block design subtests were significantly higher than at baseline (P = 0.01 and P = 0.03, respectively), and scores on Vocabulary and TIQ remained similar compared to baseline. At baseline, children with a maternal uniparental disomy had a significantly lower score on the Block design subtest (P = 0.01) but a larger increment on this subtest during 4 yr of GH treatment than children with a deletion. Lower baseline scores correlated significantly with higher increases in Similarities (P = 0.04) and Block design (P < 0.0001) sd scores. CONCLUSIONS: Our study shows that GH treatment prevents deterioration of certain cognitive skills in children with PWS on the short term and significantly improves abstract reasoning and visuospatial skills during 4 yr of GH treatment. Furthermore, children with a greater deficit had more benefit from GH treatment.01 juli 201