A missense mutation (p.G274R) in gene ASPA causes Canavan disease in a Pakistani family

Combined transcriptome and proteome analyses reveal differences in the longissimus dorsi muscle between Kazakh cattle and Xinjiang brown cattle

Objective

With the rapid development of proteomics sequencing and RNA sequencing technology, multi-omics analysis has become a current research hotspot. Our previous study indicated that Xinjiang brown cattle have better meat quality than Kazakh cattle. In this study, Xinjiang brown cattle and Kazakh cattle were used as the research objects.

Methods

Proteome sequencing and RNA sequencing technology were used to analyze the proteome and transcriptome of the longissimus dorsi muscle of the two breeds of adult steers (n = 3).

Results

In this project, 22,677 transcripts and 1,874 proteins were identified through quantitative analysis of the transcriptome and proteome. By comparing the identified transcriptome and proteome, we found that 1,737 genes were identified at both the transcriptome and proteome levels. The results of the study revealed 12 differentially expressed genes and proteins: troponin I1, crystallin alpha B, cysteine, and glycine rich protein 3, phosphotriesterase-related, myosin-binding protein H, glutathione s-transferase mu 3, myosin light chain 3, nidogen 2, dihydropyrimidinase like 2, glutamate-oxaloacetic transaminase 1, receptor accessory protein 5, and aspartoacylase. We performed functional enrichment of these differentially expressed genes and proteins. The Kyoto encyclopedia of genes and genomes results showed that these differentially expressed genes and proteins are enriched in the fatty acid degradation and histidine metabolism signaling pathways. We performed parallel reaction monitoring (PRM) verification of the differentially expressed proteins, and the PRM results were consistent with the sequencing results.

Conclusion

Our study provided and identified the differentially expressed genes and proteins. In addition, identifying functional genes and proteins with important breeding value will provide genetic resources and technical support for the breeding and industrialization of new genetically modified beef cattle breeds.

A case of juvenile Canavan disease with distinct pons involvement

BACKGROUND

Canavan disease is a genetic neurodegenerative leukodystrophy that results in the spongy degeneration of the white matter. Its key clinical features in the infantile form are developmental delay, visual problems and macrocephaly. Congenital and juvenile forms have also been described.

PATIENT DESCRIPTION

We report on a 13-year-old boy who is a high school student in a public school. He was diagnosed with juvenile Canavan disease, presenting with intentional tremor as the only clinical finding.

RESULTS

Magnetic resonance imaging revealed mainly the involvement of the caudate nucleus and pons extending to the mesencephalon and also the putamen and the thalamus, with no apparent signal increase in the cerebral white matter. A homozygous p.Gly274Arg (c.820A>G) missense mutation was identified.

CONCLUSION

Juvenile Canavan disease with mainly pons involvement has not been published before. Pons, caudate nucleus and basal ganglia involvement without any white matter being involved could be expected in juvenile Canavan disease as a rare form of the disease.

Computational analysis of deleterious missense mutations in aspartoacylase that cause Canavan's disease

In this work, the most detrimental missense mutations of aspartoacylase that cause Canavan's disease were identified computationally and the substrate binding efficiencies of those missense mutations were analyzed. Out of 30 missense mutations, I-Mutant 2.0, SIFT and PolyPhen programs identified 22 variants that were less stable, deleterious and damaging respectively. Subsequently, modeling of these 22 variants was performed to understand the change in their conformations with respect to the native aspartoacylase by computing their root mean squared deviation (RMSD). Furthermore, the native protein and the 22 mutants were docked with the substrate NAA (N-Acetyl-Aspartic acid) to explain the substrate binding efficiencies of those detrimental missense mutations. Among the 22 mutants, the docking studies identified that 15 mutants caused lower binding affinity for NAA than the native protein. Finally, normal mode analysis determined that the loss of binding affinity of these 15 mutants was caused by altered flexibility in the amino acids that bind to NAA compared with the native protein. Thus, the present study showed that the majority of the substrate-binding amino acids in those 15 mutants displayed loss of flexibility, which could be the theoretical explanation of decreased binding affinity between the mutant aspartoacylases and NAA.