48, XXXY/49, XXXXY mosaic: new neuroradiological features in an ultra-rare syndrome

BACKGROUND: Sex chromosomal aneuploidies in males are rare diseases with an overwhelming involvement of endocrinological and auxological issues; less frequently, other anomalies are observed. Neuroradiological issues are often not taken into account in single patients, and neuroradiological examinations are rarely performed. CASE PRESENTATION: Here, we report a boy with 48,XXXY/49,XXXXY mosaicism, phenotypically characterized by hypotonia, intellectual disability, ventricular septal defect, micropenis, and with mild hypertelorism, inverted nipples, a congenital hip dysplasia, and some neuroradiological features so far not described. The Magnetic Resonance Imaging showed white matter abnormalities and enlargement of lateral ventricles with never described dysmorphisms of cranio-cervical junction and posterior fossa. A cranio-cervical Computerized Tomography confirmed a dysmorphic aspect of the posterior fossa and occipital condyles, slight morphological asymmetry of C1 and slight lateralization to the right of the odontoid’s apex. CONCLUSIONS: Considering the possible relevant clinical impact of these findings, the neuroradiological assessment seems potentially useful to the diagnostic approach of these patients.