Clinical phenotype and genetic analysis of pyridoxine dependent epilepsy induced by aldehyde dehydrogenase 7 family member A1 gene mutation / 中华神经科杂志

ABSTRACT

Objective:To investigate the clinical phenotypes, therapy and genetic features of aldehyde dehydrogenase 7 family member A1 (ALDH7A1) gene mutations in five cases of pyridoxine dependent epilepsy (PDE) with diagnosis confirmed by next generation sequencing.Methods:Retrospective analysis was carried out on clinical data of five cases of PDE children with early epilepsy onset who were treated in the Department of Neurology of Children′s Hospital Affiliated to Zhengzhou University from February 2018 to November 2019. Next generation sequencing approach was used for genetic sequencing of proband ALDH7A1 gene and the first generation Sanger was used for validation of family members. And the characteristics of gene mutations were analyzed.Results:Among the five children diagnosed with PDE, the male to female ratio was 4 ∶ 1 and ages at clinic visit ranged from two months to 10 months old. In clinical phenotypes, all five cases experienced onset in neonatal period, with repeated seizures, manifested as myoclonus, spasms or focal paroxysm. The administration of antiepileptic drugs performed poorly in seizure control while long term oral intake of large dose pyridoxine showed better efficacy. All the five cases of children came from compound heterozygous mutations of father and mother, i.e. slicing homozygous mutation c.247-2(IVS2)A>T, missense mutation c.584A>G (p.N195S) and nonsense mutation c.1003C>T(p.R335 *), missense mutation c.1553G>C(p.R518T) and c.1547A>G(p.Y516C), missense mutation c.1547A>G(p.Y516C) and frameshift mutation c.1566_1568delTAC, missense mutation c.1061A>G(p.Y354C) and nonsense mutation c.841C>T(p.Q281X, 259), among which c.247-2(IVS2)A>T was novel splicing site mutation not reported before. Conclusions:PDE is induced by ALDH7A gene mutation. Early clinical manifestations are mostly onset of refractory epilepsy in neonatal period. Antiepileptic drugs perform poorly in terms of efficacy while pyridoxine can control seizure effectively. Gene analysis should be conducted on such patients for confirmed diagnosis.