Introduction: Mucopolysaccharidosis II (MPS II) is an X-linked genetic disease which almost exclusively affects males. The disease presents a multisystem form, caused by the progressive accumulation of glycosaminoglycans (GAGs) in tissues and organs. It causes developmental delays resulting in limitations on the performance of day-to-day activities. Objective: The aim of this study was to identify occupational performance areas in which people with MPS II have greater impairment and analyze their family’s socioeconomic profile. Method: The research was done through interviews with an individual responsible for three adolescent brothers, (A1-19 years, A2-16 years and A3-15 years) who are MPS II carriers from Alagoas, Brazil. Data collection was performed by a trained professional using the Functional Independence Measure (FIM) as a questionnaire to identify the functional losses and the ABEP for socioeconomic profile analysis. Results: The results showed that the family is included in the C1 socioeconomic class. Among the siblings, A1 presents total dependence on the investigated skills; A2 presents the most disabling functional losses requiring moderate assistance and A3 has much of his physical and cognitive skills preserved, but has modified dependence. Conclusion: Taking into consideration the difficulties identified in this study, we highlighted the importance of early diagnosis and rehabilitation therapies combined with enzyme therapy, which can delay disease progression.