A Patient with a Small Deletion Affecting Only Exon 1-Intron 1 of the NXF5 Gene: Potential Evidence Supporting Its Role in Neurodevelopmental Disorders

Genetic studies have identified numerous candidate genes for neurodevelopmental disorders associated with intellectual disability (ID) and autism spectrum disorders (ASD). Some genetic anomalies are very rare or challenging to detect, making it essential to validate the presence of gene mutations or copy number variations in additional patients with similar clinical phenotypes. Background/Objectives: Case reports play a crucial role in this process by validating rare variants in phenotypically matched patients, shedding light on novel candidate genes linked to these disorders. Methods: Patients with ID and ASD underwent neurological examinations, brain magnetic resonance imaging (MRI), sleep and wake electroencephalogram (EEG), neuropsychological evaluations, and laboratory tests including molecular analysis for fragile-X syndrome and array comparative genomic hybridization (aCGH). Results: We observed a patient with ID and ASD who carried a microdeletion in Xq22.1 that affects only exon 1 and intron 1 of the Nuclear RNA Export Factor 5 (NXF5) gene. The patient’s phenotypic features overlap with those of the only four previously reported cases of variations involving the same gene. Conclusions: Our findings suggest that NXF5 may play a role in neurodevelopmental disorders and should be considered in the spectrum of X-linked ID associated with ASD.