Unknown

Dataset Information

0

A recurrent de novo missense mutation in UBTF causes developmental neuroregression.


ABSTRACT: UBTF (upstream binding transcription factor) exists as two isoforms; UBTF1 regulates rRNA transcription by RNA polymerase 1, whereas UBTF2 regulates mRNA transcription by RNA polymerase 2. Herein, we describe 4 patients with very similar patterns of neuroregression due to recurrent de novo mutations in UBTF (GRCh37/hg19, NC_000017.10: g.42290219C?>?T, NM_014233.3: c.628G?>?A) resulting in the same amino acid change in both UBTF1 and UBTF2 (p.Glu210Lys [p.E210K]). Disease onset in our cohort was at 2.5 to 3 years and characterized by slow progression of global motor, cognitive and behavioral dysfunction. Notable early features included hypotonia with a floppy gait, high-pitched dysarthria and hyperactivity. Later features included aphasia, dystonia, and spasticity. Speech and ambulatory ability were lost by the early teens. Magnetic resonance imaging showed progressive generalized cerebral atrophy (supratentorial?>?infratentorial) with involvement of both gray and white matter. Patient fibroblasts showed normal levels of UBTF transcripts, increased expression of pre-rRNA and 18S rRNA, nucleolar abnormalities, markedly increased numbers of DNA breaks, defective cell-cycle progression, and apoptosis. Expression of mutant human UBTF1 in Drosophila neurons was lethal. Although no loss-of-function variants are reported in the Exome Aggregation Consortium (ExAC) database and Ubtf-/- is early embryonic lethal in mice, Ubtf+/- mice displayed only mild motor and behavioral dysfunction in adulthood. Our data underscore the importance of including UBTF E210K in the differential diagnosis of neuroregression and suggest that mainly gain-of-function mechanisms contribute to the pathogenesis of the UBTF E210K neuroregression syndrome.

SUBMITTER: Toro C 

PROVIDER: S-EPMC5886272 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature

Similar Datasets

| S-EPMC5986694 | biostudies-literature
| S-EPMC5841038 | biostudies-literature
| S-EPMC4281260 | biostudies-literature
| S-EPMC5518294 | biostudies-literature
| S-EPMC5541750 | biostudies-literature
| S-EPMC4345105 | biostudies-literature
| S-EPMC5384423 | biostudies-literature
| S-EPMC5002929 | biostudies-literature
| S-EPMC8457687 | biostudies-literature
| S-EPMC7299959 | biostudies-literature