Sequencing of RNU7-1: Aicardi-Goutières syndrome [1 gene]

Aicardi-Goutières syndrome (AGS) is a heterogeneous, early-onset hereditary encephalopathy with either autosomal dominant or recessive inheritance. This disease shows typical features of inflammatory (central nervous system inflammation and tissue damage) and autoimmune pathologies (about 40% of patients with AGS show lupus pernio in the fingers and ears typical of lupus-like syndrome—SLE-like—and recurrent fevers in the absence of infection).

To date, nine genes associated with this syndrome have been described: ADAR, IFIH1, RNASEH2A, RNASEH2B, RNASEH2C, RNU7-1, SAMHD1, TREX2, and LSM11.

The RNU7-1 gene is a non-coding RNA and cannot be captured by commonly used exome sequencing kits; therefore, we have designed a specific assay for this gene. We recommend complementing this test with the Aicardi-Goutières syndrome panel (8 genes), Ref.: S-201805369, which includes the remaining genes.

• Unknown. Few families described.

Since the RNU7-1 gene cannot be captured by commonly used exome sequencing kits, this study can allow identifying patients who have already been studied and for whom no diagnosis has been reached.

The identification of the defective gene causing AGS allows reaching an accurate molecular diagnosis, which is useful to understand the pathological mechanisms of the disease and to define the inheritance pattern. Disease presentation differs depending on the causative gene. In the case of the RNU7-1 gene, the inheritance pattern is recessive.

The management of AGS patients is based on symptom management and disease follow-up. Immunosuppressive therapy is currently under research.

This study is indicated for patients with suspected Aicardi-Goutières syndrome who either have not been genetically tested or have previously tested negative (e.g. Aicardi-Goutières panel or exome sequencing).