Intragenic deletions of ALDH7A1 in pyridoxine-dependent epilepsy caused by Alu-Alu recombination.
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ABSTRACT: Objective
To investigate the role of intragenic deletions of ALDH7A1 in patients with clinical and biochemical evidence of pyridoxine-dependent epilepsy but only a single identifiable mutation in ALDH7A1.Methods
We designed a custom oligonucleotide array with high-density probe coverage across the ALDH7A1 gene. We performed array comparative genomic hybridization in 6 patients with clinical and biochemical evidence of pyridoxine-dependent epilepsy but only a single detectable mutation in ALDH7A1 by sequence analysis.Results
We found partial deletions of ALDH7A1 in 5 of 6 patients. Breakpoint analysis reveals that the deletions are likely a result of Alu-Alu recombination in all cases. The density of Alu elements within introns of ALDH7A1 suggests susceptibility to recurrent rearrangement.Conclusion
Patients with clinical pyridoxine-dependent epilepsy and a single identifiable mutation in ALDH7A1 warrant further investigation for copy number changes involving the ALHD7A1 gene.
SUBMITTER: Mefford HC
PROVIDER: S-EPMC4553021 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundLittle is known about pyridoxine-dependent epilepsy due to α-aminoadipic semialdehyde dehydrogenase deficiency (PDE-ALDH7A1) in adulthood, as the genetic basis of the disorder has only been elucidated 15 years ago. This creates a knowledge gap for physicians, pediatric patients and their parents, which was aimed to address in this study using clinical data as well as patient-reported outcome measures (PROMs) for the patient's perspective.MethodsDutch, genetically confirmed PDE-ALDH7A1 patients ≥18 years were eligible for inclusion. Clinical data were collected as well as PROMs (PROMIS item banks Anxiety, Depression, Anger, Physical Functioning, Cognitive Functioning, Cognitive Abilities, Ability to Participate and Satisfaction with Social Roles).ResultsTen out of 11 patients agreed to participate (91% response rate). Seizure control at last follow up (median age 25.2 years, range 17.8-29.8 years) was achieved with pyridoxine monotherapy in 70%, 20% with adjunct common-anti epileptic drugs and 10% did not obtain complete seizure control. Neurologic symptoms were present in all but one patient (90%) and included tremors, noted in 40%. Neuro-imaging abnormalities were present in 80%. Intellectual disability was present in 70%. One patient (10%) attended university, three maintained a job without assistance, five maintained a job with assistance or attended social daycare, and one patient never followed regular education. The cohort scored significantly lower on the PROMIS Cognitive Functioning compared to the general (age-related) population. Distribution of scores was wide on all PROMIS item banks.Discussion & conclusionOutcomes of this young adult cohort are heterogeneous and individualized approaches are therefore needed. Long-term seizure control with pyridoxine was achieved for almost all patients. Neurologic symptoms were noted in the majority, including tremors, as well as neuro-imaging abnormalities and intellectual disability, additionally reflected by the PROMIS Cognitive Functioning. PDE-ALDH7A1 patients scored comparable to the general population on all other PROMs, especially regarding Ability to Participate and Satisfaction with Social Roles this may indicate a positive interpretation of their functioning. The aim is to expand this pilot study to larger populations to obtain more solid data, and to advance the use of PROMs to engage patients in research and provide the opportunity for personalized care.
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