A de novo p.Asp18Asn mutation in TREX1 in a patient with Aicardi-Goutières syndrome.

Aicardi-Goutières syndrome is a rare, genetically determined encephalopathy often resembling congenital infection. Mutations in the TREX1 gene are found in approximately 25% of patients. Aicardi-Goutières syndrome is usually inherited as an autosomal recessive trait, although a single case of a heterozygous TREX1 mutation associated with the syndrome has been reported. We present a second case of a de novo heterozygous TREX1 mutation causing an autosomal dominant phenotype of Aicardi-Goutières syndrome with additional features indicative of mitochondrial dysfunction. This report serves to enhance awareness of de novo heterozygous mutations underlying Aicardi-Goutières syndrome-with a concomitant low risk of recurrence.