RT Journal Article
SR Electronic
T1 Pathogenic Effect of <em>TP73</em> Gene Variants in People With Amyotrophic Lateral Sclerosis
JF Neurology
JO Neurology
FD Lippincott Williams &amp; Wilkins
SP e225
OP e235
DO 10.1212/WNL.0000000000012285
VO 97
IS 3
A1 Russell, Kristi L.
A1 Downie, Jonathan M.
A1 Gibson, Summer B.
A1 Tsetsou, Spyridoula
A1 Keefe, Matthew D.
A1 Duran, Jerry A.
A1 Figueroa, Karla P.
A1 Bromberg, Mark B.
A1 Murtaugh, L. Charles
A1 Bonkowsky, Joshua L.
A1 Pulst, Stefan M.
A1 Jorde, Lynn B.
YR 2021
UL http://n.neurology.org/content/97/3/e225.abstract
AB Objective To identify novel disease associated loci for amyotrophic lateral sclerosis (ALS), we used sequencing data and performed in vitro and in vivo experiments to demonstrate pathogenicity of mutations identified in TP73.Methods We analyzed exome sequences of 87 patients with sporadic ALS and 324 controls, with confirmatory sequencing in independent ALS cohorts of &gt;2,800 patients. For the top hit, TP73, a regulator of apoptosis and differentiation and a binding partner and homolog of the tumor suppressor gene TP53, we assayed mutation effects using in vitro and in vivo experiments. C2C12 myoblast differentiation assays, characterization of myotube appearance, and immunoprecipitation of p53-p73 complexes were performed in vitro. In vivo, we used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 targeting of zebrafish tp73 to assay motor neuron number and axon morphology.Results Four heterozygous rare, nonsynonymous mutations in TP73 were identified in our sporadic ALS cohort. In independent ALS cohorts, we identified an additional 19 rare, deleterious variants in TP73. Patient TP73 mutations caused abnormal differentiation and increased apoptosis in the myoblast differentiation assay, with abnormal myotube appearance. Immunoprecipitation of mutant ΔN-p73 demonstrated that patient mutations hinder the ability of ΔN-p73 to bind p53. CRISPR/Cas9 knockout of tp73 in zebrafish led to impaired motor neuron development and abnormal axonal morphology, concordant with ALS pathology.Conclusion Together, these results strongly suggest that variants in TP73 correlate with risk for ALS and indicate a role for apoptosis in ALS disease pathology.ALS=amyotrophic lateral sclerosis; CI=confidence interval; CRISPR=clustered regularly interspaced short palindromic repeats; EGFP=enhanced GFP; GFP=green fluorescent protein; H1K=Heritage 1K; hpf=hours post-fertilization; MAF=minor allele frequency; MHC=myosin heavy chain; N2A=Neuro-2A; PBS=phosphate-buffered saline; PBST=PBS-Tween; p73=protein 73; RT=room temperature; SALS=sporadic ALS; SMN=spinal motor neuron; SNV=single nucleotide variant; TUNEL=terminal deoxynucleotidyl transferase dUTP nick-end labeling