No abstract

/Herdecke University Hospital. Contrary to his brother the boy presented dystrophic at birth (1.715 g birth weight; 150 g below 3rd percentile) and developed adverse gastrointestinal conditions within the first 2 months of life. These included chronic mucosal inflammation and oedematous lamina propria in the intestine, which contributed to intractable diarrhoea. At an age of 7 months the infant eventually died of enteral haemorrhages and liver failure. Further anamnesis revealed several similar fatalities in the familial clan with reportedly frequent parental consanguinity. Intractable chronic diarrhoea in infancy are heterogeneous disorders challenging for diagnostics and therapy. Despite extensive diagnostic approaches the etiology of many cases remains elusive. Investigating putatively underlying genetic disorders might clarify many cases. ResultsTo contribute to the diagnosis we performed whole exome sequencing of the affected infant as well as his twin brother and parents. We identified a suspicious nonsynonymous single nucleotide polymorphism (SNP) in the integrin beta-6 gene (ITGB6G1312A) entailing a V438M substitution. This SNP is very rare in the G1000 cohort and predicted being potentially harmful. The allelic distribution in the genotyped family members fit well with an autosomal recessive inheritance scheme. We performed computational biological and molecular biological analyses on the α V β6 integrin receptor function suggesting that the integrin α V β6 dimerization could be impaired, potentially causing a loss of α V β6 function in wound healing and epithelial tissue integrity. Conclusions Our study provides a starting point for elucidating integrin α V β6 function and for understanding a pathomechanistical relevance of ITGB6V438M. Consent for publicationThe authors have written informed consent from the patients' guardian/parent. Metabolic treatment according to current guideline recommendations has significantly improved neurological outcome. However, cognitive functions have not yet been studied in detail. Methods In a cross-sectional design, 30 patients detected by newborn screening (n = 13), high-risk screening (n = 3) or targeted metabolic testing (n = 14) were studied for simple reaction time (SRT), continuous performance (CP), visual working memory (VWM), visual-motor coordination (Tracking) and visual search (VS). Dystonia (n = 13 patients) was categorized using the Barry-Albright-Dystonia Scale (BADS). Patients were compared with 196 healthy controls. Developmental functions of cognitive performances were analysed using a negative exponential function model. Results BADS scores correlated with speed tests but not with tests measuring stability or higher cognitive functions without time constraints. Developmental functions of GA-I patients significantly differed from controls for SRT and VS but not for VWM and showed obvious trends for CP and Tracking. Dystonic patients were slower in SRT and CP but reached their asymptote of performance similar to asymptomatic patients and controls in all...