Phenylketonuria is an inborn error of phenylalanine (Phe) metabolism diagnosed by newborn screening and treated early with diet. Although diet prevents intellectual disability, patients often show impairment of executive functions, working memory, sustained attention, and cognitive flexibility. Large neutral amino acids (LNAAs) have been proposed as a dietary supplement for PKU adults. Few studies show that LNAAs may help in improving metabolic control as well as cognitive functions. In this study, 10 adult PKU patients with poor metabolic control were treated for 12 months with LNAAs (MovisCom, 0.8–1 g/kg/day) and underwent Phe and Tyrosine (Tyr) monitoring monthly. Neuropsychological assessment was performed at T0, T+3, and T+12 months by using the American Psychological General Well-Being Index, the Wisconsin Card Sorting Test, the Test of Attentional Performance, and the 9-Hole Peg Test. No change in plasma Phe levels was observed during LNAAs supplementation, while Tyr levels significantly improved during LNAAs supplementation (p = 0.03). Psychometric tests showed an improvement of distress and well-being rates, of executive functions, attention, and vigilance, whereas no difference was noted regarding hand dexterity. This study adds evidence of the advantage of LNAAs supplementation in improving cognitive functions and well-being in patients with PKU with poor metabolic control.

Aim of the study is to intercept specific characteristics and psychiatric comorbidity in Down Syndrome (DS). The study describes the distribution and the age of specific aspects of behavioral phenotype in a sample of subjects with DS. Psychopathological risk has been evaluated in a 97 DS patient cohort, aged 1 to 18 years, during regular follow-up neuropsychiatric visit and through administration of Child Behavior Checklist (CBCL); Childhood Autism Rating Scale (CARS-T) was assessed to verify the presence of autistic behaviors. The results show the presence of specific psychopathological risk factors in 90% of the sample. 7% of sample presents autistic features. The risk of psychopathology is independent of the degree of intellectual disability. The high frequency of psychopathological risk factors indicates the need for accurate monitoring to intercept specific characteristics, such as in the case of comorbidity for autism. The search for specific psychopathological factors is a little explored aspect to date, as evidenced by the literature. Despite the studies available to date highlight the presence of psychopathological vulnerability in DS, so far there are only few reports that explore this issue systematically.