BackgroundPartial deletion of chromosome 21q is a very rare chromosomal abnormality associated with highly variable phenotypes, such as facial dysmorphic features, heart defects, seizures, psychomotor delay, and severe to mild intellectual disability, depending on the location and size of deletions. So far, three broad deletion regions of 21q have been correlated with the clinical phenotype.ResultsWe described the clinical and genetic features of three family members (father and two siblings) and other two unrelated patients with very wide range in age of diagnosis. All of them showed intellectual disability with very variable symptoms, from mild to severe, and carried 21q interstitial deletions with different sizes and position, as detected by conventional karyotype and array-CGH.ConclusionsOur study provided additional cases of partial 21q deletions, allowing to better delineate the genotype-phenotype correlations. In contrast to previous observations, we showed that deletions of the 21q proximal region are not necessarily associated with severe phenotypes and, therefore, that mild phenotypes are not exclusively related to distal deletions. To the best of our knowledge, this is the first report showing 21q deletions in adult patients associated with mild phenotypes, mainly consisting of neurobehavioral abnormalities, such as obsessive-compulsive disorders, poor social interactions and vulnerability to psychosis.

Klinefelter's syndrome (KS) is due to the presence of one or more supernumerary X chromosomes. Aneuploidy 47,XXY is the most common abnormality of sex chromosomes in humans, with an incidence of 1/500 male live births. Only one-third of subjects with KS is, however, diagnosed. The aim of this work is to present a review of current literature about neurogenetic functions in KS, referring to both clinical and therapeutics aspects. If it is well known that the majority of subjects with 47,XXY karyotype have a normal intellectual level, the identification of strengths and weaknesses of their intellectual functioning is important for the purpose of planning early psycho-educational interventions. Language difficulties are one of the more distinctive traits in cognitive functioning of people with KS. It has also been suggested that the limitations in communication markedly affect social adaptation and behavioral aspects, as well as the development of personality. Moreover, difficulties in learning language appear to be related to an altered functional lateralization; therefore, KS subjects are a suitable model for studying genetic abnormalities of lateralization. In this, perspective psychopathological risk is analyzed. Early recognition of this aspect is needed to address the educational and therapeutic perspectives for KS subjects.

Five years after the first edition, we have revised and updated the guidelines, re-examining the queries and relative recommendations, expanding the issues addressed with the introduction of a new entity, recently proposed by the American Academy of Pediatrics: BRUE, an acronym for Brief Resolved Unexplained Events. In this manuscript we will use the term BRUE only to refer to mild, idiopathic cases rather than simply replace the acronym ALTE per se.In our guidelines the acronym ALTE is used for severe cases that are unexplainable after the first and second level examinations.Although the term ALTE can be used to describe the common symptoms at the onset, whenever the aetiology is ascertained, the final diagnosis may be better specified as seizures, gastroesophageal reflux, infection, arrhythmia, etc. Lastly, we have addressed the emerging problem of the so-called Sudden Unexpected Postnatal Collapse (SUPC), that might be considered as a severe ALTE occurring in the first week of life.