Mutations in RNU7-1 Weaken Secondary RNA Structure, Induce MCP-1 and CXCL10 in CSF, and Result in Aicardi-Goutières Syndrome with Severe End-Organ Involvement.

BACKGROUND: Aicardi-Goutières syndrome (AGS) is a type I interferonopathy usually characterized by early-onset neurologic regression. Biallelic mutations in LSM11 and RNU7-1, components of the U7 small nuclear ribonucleoprotein (snRNP) complex, have been identified in a limited number of genetically unexplained AGS cases. Impairment of U7 snRNP function results in misprocessing of replication-dependent histone (RDH) pre-mRNA and disturbance of histone occupancy of nuclear DNA, ultimately driving cGAS-dependent type I interferon (IFN-I) release. OBJECTIVE: We performed a clinical, genetic, and immunological workup of 3 unrelated patients with uncharacterized AGS. METHODS: Whole exome sequencing (WES) and targeted Sanger sequencing of RNU7-1 were performed. Primary fibroblasts were used for mechanistic studies. IFN-I signature and STAT1/2 phosphorylation were assessed in peripheral blood. Cytokines were profiled on serum and cerebrospinal fluid (CSF). Histopathology was examined on brain and kidney tissue. RESULTS: Sequencing revealed compound heterozygous RNU7-1 mutations, resulting in impaired RDH pre-mRNA processing. The 3' stem-loop mutations reduced stability of the secondary U7 snRNA structure. A discrete IFN-I signature in peripheral blood was paralleled by MCP-1 (CCL2) and CXCL10 upregulation in CSF. Histopathological analysis of the kidney showed thrombotic microangiopathy. We observed dysregulated STAT phosphorylation upon cytokine stimulation. Clinical overview of all reported patients with RNU7-1-related disease revealed high mortality and high incidence of organ involvement compared to other AGS genotypes. CONCLUSIONS: Targeted RNU7-1 sequencing is recommended in genetically unexplained AGS cases. CSF cytokine profiling represents an additional diagnostic tool to identify aberrant IFN-I signaling. Clinical follow-up of RNU7-1-mutated patients should include screening for severe end-organ involvement including liver disease and nephropathy.

Homozygous missense STRADA mutation in a patient with polyhydramnios, megalencephaly and symptomatic epilepsy syndrome.

Homozygous or compound heterozygous mutations in STRADA cause polyhydramnios, megalencephaly and symptomatic epilepsy syndrome (PMSE), with additional features of distinctive facial traits and severe developmental delay or intellectual disability. This syndrome was first defined in 16 Old Order Mennonite patients, carrying a homozygous STRADA deletion of exon 9-13. Five additional PMSE patients have been reported since, each of them with loss-of-function variants. We report a female patient with the typical clinical features of PMSE, homozygous for a novel STRADA missense mutation c.792T>A (p.Ser264Arg) in exon 10. This finding contributes to the further delineation of the phenotype of PMSE.

Pediatric Outcome after Maternal Cancer Diagnosed during Pregnancy.

BACKGROUND: Data on the long-term outcome of children who are exposed to maternal cancer with or without treatment during pregnancy are lacking. METHODS: In this multicenter case-control study, we compared children whose mothers received a diagnosis of cancer during the pregnancy with matched children of women without a cancer diagnosis. We used a health questionnaire and medical files to collect data regarding neonatal and general health. All children were prospectively assessed (by means of a neurologic examination and the Bayley Scales of Infant Development) at 18 months, 36 months, or both. A cardiac assessment was performed at 36 months. RESULTS: A total of 129 children (median age, 22 months; range, 12 to 42) were included in the group whose mother had cancer (prenatal-exposure group) with a matching number in the control group. During pregnancy, 96 children (74.4%) were exposed to chemotherapy (alone or in combination with other treatments), 11 (8.5%) to radiotherapy (alone or in combination), 13 (10.1%) to surgery alone, 2 (1.6%) to other drug treatments, and 14 (10.9%) to no treatment. Birth weight was below the 10th percentile in 28 of 127 children (22.0%) in the prenatal-exposure group and in 19 of 125 children (15.2%) in the control group (P=0.16). There was no significant between-group difference in cognitive development on the basis of the Bayley score (P=0.08) or in subgroup analyses. The gestational age at birth was correlated with the cognitive outcome in the two study groups. Cardiologic evaluation among 47 children at 36 months of age showed normal cardiac findings. CONCLUSIONS: Prenatal exposure to maternal cancer with or without treatment did not impair the cognitive, cardiac, or general development of children in early childhood. Prematurity was correlated with a worse cognitive outcome, but this effect was independent of cancer treatment. (Funded by Research Foundation-Flanders and others; ClinicalTrials.gov number, NCT00330447.).