Untangling adaptive functioning of PMM2-CDG across age and its impact on parental stress: a cross-sectional study

Phosphomannomutase deficiency (PMM2-CDG) leads to cerebellar atrophy with ataxia, dysmetria, and intellectual deficits. Despite advances in therapy, the cognitive and adaptive profile remains unknown. Our study explores the adaptive profile of 37 PMM2-CDG patients, examining its association with parental stress and medical characteristics. Assessment tools included ICARS for the cerebellar syndrome and NPCRS for global disease severity. Behavioral and adaptive evaluation consisted of the Vineland Adaptive Behavior Scale and the Health of the Nation Outcome Scales. Psychopathological screening involved the Child Behavior Checklist and the Symptom Check-List-90-R. Parental stress was evaluated using Parental Stress Index. Results were correlated with clinical features. No significant age or sex differences were found. 'Daily living skills' were notably affected. Patients severely affected exhibited lower adaptive skill values, as did those with lipodystrophy and inverted nipples. Greater severity in motor cerebellar syndrome, behavioral disturbances and the presence of comorbidities such as hyperactivity, autistic features and moderate-to-severe intellectual disability correlated with greater parental stress. Our study found no decline in adaptive abilities. We provide tools to assess adaptive deficits in PMM2-CDG patients, emphasizing the importance of addressing communication, daily living skills, and autonomy, and their impact on parental stress in clinical monitoring and future therapies.