Abstrakt
A 9-year follow-up of a patient with an attenuated (type II) adenylosuccinate lyase deficiency with no obvious signs of disease progression and degradation. We also review the literature, focusing on attenuated phenotype, and we report a positive effect of a ketogenic diet on seizure control.
The patient presented at the age of 5 months with a history of global developmental delay. Screening of urinary purine metabolites revealed elevation of succinyladenosine and succinylaminoimidazolecarboxamide riboside (a ratio of 2:1).
Mutation analysis revealed a compound heterozygosity for missense mutations: p.R426H and p.D268H. She began to walk independently at the age of 3 years.
From the age of 4 years, her communication skills improved and she presented fewer autistic features. Due to poor results in seizure control, the ketogenic diet was introduced at the age of 7 years, resulting in reduction of seizure frequency.
Currently, at the age of 9 years, the girl is attending a special kindergarten and is functioning very well in her preschool group.