Klinefelter’s syndrome (KS) is considered as a genetic risk factor for intellectual disability and specifically for impairment on verbal skills. Prenatal and perinatal morbidity concurrent with this diagnosis determine the entity and typology of neurodevelopmental deficits.

To describe the intellectual and adaptive functioning of a patient with KS and prenatal and perinatal difficulties, assessed in the Service of Psychiatry, Clinical Psychology and Mental Health at La Paz University Hospital (Madrid).

A descriptive study was conducted of a 6 year and 7-month-old boy with diagnosis of KS (karyotype XXY), extremely low weight at birth (752 gr.), Arnold Chiari type I malformation with post-hemorrhagic hydrocephalus and periventricular leukomalacia, bronchopulmonary dysplasia, intra-atrial septal defect, left kidney agenesis with iatrogenic adrenal insufficiency, and acute ventriculitis due to E. Coli. Neuropsychological evaluation was carried out in October 2021. Leiter-3 scale was selected due to the absence of expressive language; and his parents completed the questionnaire Adaptive Behavior Assessment System-II.

The nonverbal intelligence quotient was observed in the very low range (full-scale IQ = 69). The result of general adaptive behavior (z = -2.83), showed very high functional disability both in the conceptual, social, and practical domains.

The high number of causes of disability in this patient is consistent with a high degree of functional disability. Efficient evaluation sessions of intellectual performance, adaptive functioning, and necessary supports, due to the absence of expressive language and limited receptive language, are required. A specific neuropsychological evaluation profile should be established for KS.

No significant relationships.