AUTHOR=Tian Qi , Shu Li , Zhang Pu , Zeng Ting , Cao Yang , Xi Hui , Peng Ying , Wang Yaqin , Mao Xiao , Wang Hua TITLE=MN1 Neurodevelopmental Disease-Atypical Phenotype Due to a Novel Frameshift Variant in the MN1 Gene JOURNAL=Frontiers in Molecular Neuroscience VOLUME=Volume 14 - 2021 YEAR=2021 URL=https://www.frontiersin.org/journals/molecular-neuroscience/articles/10.3389/fnmol.2021.789778 DOI=10.3389/fnmol.2021.789778 ISSN=1662-5099 ABSTRACT=

Background:MN1 C-terminal truncation (MCTT) syndrome is caused by variants in the C-terminal region of MN1, which were first described in 2020. The clinical features of MCTT syndrome includes severe neurodevelopmental and brain abnormalities. We reported on a patient who carried the MN1 variant in the C-terminal region with mild developmental delay and normal brain magnetic resonance image (MRI).

Methods: Detailed clinical information was collected in the pedigree. Whole-exome sequencing (WES) accompanied with Sanger sequencing validation were performed. A functional study based on HEK239T cells was performed.

Results: A de novo heterozygous c.3734delT: p.L1245fs variant was detected. HEK239T cells transinfected with the de novo variant showed decreased proliferation, enhanced apoptotic rate, and MN1 nuclear aggregation.

Conclusion: Our study expended the clinical and genetic spectrum of MCTT which contributes to the genetic counseling of the MN1 gene.