PNKP Mutations Identified by Whole-Exome Sequencing in a Norwegian Patient with Sporadic Ataxia and Edema.

We identified PNKP mutations in a Norwegian woman with AOA. This patient had the typical findings with cognitive dysfunction, peripheral neuropathy, cerebellar dysarthria, horizontal nystagmus, oculomotor apraxia, and severe truncal and appendicular ataxia. In addition, she had hypoalbuminemia and massive lower limb edema which showed some improvement with treatment. Exome sequencing identified two heterozygous mutations, one in exon 14 (c.1196T>C, p.Leu399Pro) and one in exon 16 (c.1393_1396del, p.Glu465*). This is the first non-Portuguese patient with AOA due to PNKP mutations and provides independent verification that PNKP mutations cause AOA.