Background: Sex chromosome aneuploidies (SCAs) are a group of disorders characterised by an abnormal number of sex chromosomes. Collective prevalence rate of SCAs is estimated to be around 1 in 400–500 live births; sex chromosome trisomies (e.g., XXX, XXY, XYY) are most frequent, while tetra- and pentasomies (e.g., XXXX, XXXXX, XXXY, XXXXY) are rarer, and the most common is 48, XXYY syndrome. The presence of additional X and/or Y chromosomes is believed to cause neurodevelopmental differences, with increased risk for developmental delays, language-based learning disabilities, cognitive impairments, executive dysfunction, and behavioural and psychological disorders. Aim of the Study: Our review has the purpose of analysing the neurocognitive, linguistical and behavioural profile of patients affected by sex chromosomes supernumerary aneuploidies (tetrasomy and pentasomy) to better understand the specific areas of weakness, in order to provide specific rehabilitation therapy. Methods: The literature search was performed by two authors independently. We used MEDLINE, PubMed, and PsycINFO search engines to identify sources of interest, without year or language restrictions. At the end of an accurate selection, 16 articles fulfilled the inclusion and exclusion criteria. Results and Conclusions: International literature has described single aspects of the neuropsychological profile of 48, XXYY and 49, XXXXY patients. In 48, XXYY patients, various degrees of psychosocial/executive functioning issues have been reported and there is an increased frequency of behavioural problems in childhood. Developmental delay and behavioural problems are the most common presenting problems, even if anxiety, depression and oppositional defiant disorder are also reported. They also show generalized difficulties with socialization and communication. Cognitive abilities are lower in measures of verbal IQ than in measures of performance IQ. Visuospatial skills are a relative strength compared to verbal skills. In patients with 49, XXXXY, both intellectual and adaptive functioning skills fall into the disability range, with better non-verbal cognitive performance. Speech and language testing reveals more deficits in expressive language than receptive language and comprehension. Anxiety, thought problems, internalizing and externalizing problems, and deficits in social cognition and communication are reported. Behavioural symptoms lessen from school age to adolescence, with the exception of thought problems and anxiety. Individuals affected by sex chromosome aneuploidies show testosterone deficiency, microorchidism, lack of pubertal progression and infertility. Hormone replacement therapy (HRT) is usually recommended for these patients: different studies have found that testosterone-based HRT benefit a wide range of areas initiated in these disorders, affecting not only neuromotor, cognitive and behavioural profile but also structural anomalies of the brain (i.e., increase of volume of grey temporal lobe matter). In conclusion, further studies are needed to better understand the neuropsychological profile with a complete evaluation, including neurocognitive and psychosocial aspects and to establish the real impact of HRT on improving the cognitive and behavioural profile of these patients.

Inherited disorders of biogenic amine metabolism are genetically determined conditions resulting in dysfunctions or lack of enzymes involved in the synthesis, degradation, or transport of dopamine, serotonin, adrenaline/noradrenaline, and their metabolites or defects of their cofactor or chaperone biosynthesis. They represent a group of treatable diseases presenting with complex patterns of movement disorders (dystonia, oculogyric crises, severe/hypokinetic syndrome, myoclonic jerks, and tremors) associated with a delay in the emergence of postural reactions, global development delay, and autonomic dysregulation. The earlier the disease manifests, the more severe and widespread the impaired motor functions. Diagnosis mainly depends on measuring neurotransmitter metabolites in cerebrospinal fluid that may address the genetic confirmation. Correlations between the severity of phenotypes and genotypes may vary remarkably among the different diseases. Traditional pharmacological strategies are not disease-modifying in most cases. Gene therapy has provided promising results in patients with DYT-DDC and in vitro models of DYT/PARK-SLC6A3. The rarity of these diseases, combined with limited knowledge of their clinical, biochemical, and molecular genetic features, frequently leads to misdiagnosis or significant diagnostic delays. This review provides updates on these aspects with a final outlook on future perspectives.

Objectives: To investigate the clinical value of cerebrospinal fluid (CSF) testing for biogenic amine, pterins, amino acids, and folates in paediatric onset epilepsies. Methods: Retrospective clinical and biochemical phenotyping of patients with epilepsy who underwent diagnostic CSF measurement of monoamine neurotransmitters, pterins, folates, and amino acids between 2009 and 2022. Results: The studied cohort included 123 patients with epilepsy (mean age at the procedure: 4.54 ± 3.65 years). The diagnostic yield for primary neurotransmitter disorders was 1.68% and zero for inherited amino acid and folate metabolism disorders. Patients with higher seizure frequency showed higher levels of CSF homovanillic acid (HVA) and HVA/5-hydroxyindolacetic acid (5HIAA) ratio. Lower levels of 3-O-methyldopa (3-OMD) were found in patients with co-occurring neurodevelopmental disorders, and lower levels of biopterin, 3-methoxy-4-hydroxyphenylglycol (3-MHPG) and 5-methyltetrahydrofolate (5-MTHF) in those with movement disorders. Significantly lower CSF glutamine levels were found in patients receiving antiseizure medications as polytherapy. Patients with a history of status epilepticus had significantly lower levels of CSF aspartic acid, glycine, leucine, ornithine, and valine, and higher levels of CSF serine. Conclusions: CSF analysis disclosed differences in the concentrations of various metabolites that might be related to the severity of the epilepsy, the presence of comorbid conditions, and medications.