A novel COL2A1 mutation causing spondyloepiphyseal dysplasia congenita in a Chinese family

Surgical treatment of atlantoaxial dysplasia and scoliosis in spondyloepiphyseal dysplasia congenita: A case report

BACKGROUND

Spondyloepiphyseal dysplasia congenita (SEDC) is a rare autosomal dominant hereditary disease caused by COL2A1 mutations. SEDC primarily involves the skeletal system, with typical clinical manifestations, including short stature, hip dysplasia, and spinal deformity. Due to the low incidence of SEDC, there are only a few case reports regarding the surgical treatment of SEDC complicated with spinal deformities.

CASE SUMMARY

We report a case of a 16-year-old male patient with SEDC. He presented with typical short stature, atlantoaxial dysplasia, scoliosis, and hip dysplasia. Cervical magnetic resonance imaging showed spinal canal stenosis at the atlas level and cervical spinal cord compression with myelopathy. The scoliosis was a right thoracic curve with a Cobb angle of 65°. He underwent atlantoaxial reduction, decompression, and internal fixation from C1–C2 to relieve cervical myelopathy. Three months after cervical surgery, posterior correction surgery for scoliosis was performed from T3 to L4. Scoliosis was corrected from 66° to 8° and remained stable at 2-year follow-up.

CONCLUSION

This is the first case report of a patient with SEDC who successfully underwent surgery for atlantoaxial dysplasia and scoliosis. The study provides an important reference for the surgical treatment of SEDC complicated with spinal deformities.

Comparative Transcriptome Analysis of Spleen Reveals Potential Regulation of Genes and Immune Pathways Following Administration of Aeromonas salmonicida subsp. masoucida Vaccine in Atlantic Salmon (Salmo salar)

Aeromonas salmonicida is a global fish pathogen. Aeromonas salmonicida subsp. masoucida (ASM) is classified as atypical A. salmonicida and caused huge losses to salmonid industry in China. Hence, it is of great significance to develop ASM vaccine and explore its protection mechanism in salmonids. In this regard, we conducted RNA-seq analysis with spleen tissue of Atlantic salmon after ASM vaccination to reveal genes, their expression patterns, and pathways involved in immune protections. In our results, a total of 441.63 million clean reads were obtained, and 389.37 million reads were mapped onto the Atlantic salmon reference genome. In addition, 1125, 2126, 1098, 820, and 1351 genes were significantly up-regulated, and 747, 2626, 818, 254, and 908 genes were significantly down-regulated post-ASM vaccination at 12 h, 24 h, 1 month, 2 months, and 3 months, respectively. Subsequent pathway analysis revealed that many differentially expressed genes (DEGs) following ASM vaccination were involved in cytokine-cytokine receptor interaction (TNFRSF11b, IL-17RA, CCR9, and CXCL11), HTLV-I infection (MR1 and HTLV-1), MAPK signaling pathway (MAPK, IL8, and TNF-α-1), PI3K-Akt signaling pathway (PIK3R3, THBS4, and COL2A1), and TNF signaling pathway (PTGS2, TNFRSF21-l, and CXCL10). Finally, the results of qRT-PCR showed a significant correlation with RNA-seq results, suggesting the reliability of RNA-seq for gene expression analysis. This study provided insights into regulation of gene expression and their involved pathways in Atlantic salmon spleen in responses to vaccine, and set the foundation for further study on the vaccine protective mechanism in Atlantic salmon as well as other teleost species.

De novo mutation in COL2A1 leads to lethal foetal skeletal dysplasia

OBJECTIVE

Skeletal dysplasia caused by genetic mutations places a heavy burden on families and society. This study was performed to precise diagnosis of variants of unknown significance and to expand the genotypic spectrum of lethal skeletal dysplasia.

METHODS

According to the ultrasonic phenotype of the proband and whole-exome sequencing results, variation sites or genes that may be related to the disease were screened out. We verified the accuracy of the variation site through Sanger sequencing. Using bioinformatics, zebrafish models, and assisted reproduction technology (ART) combined with preimplantation genetic testing for monogenic diseases, the disease-causing mutation was verified.

RESULTS

A missense mutation (c.3944G>A, p.Cys1315Tyr) was found in the coding region of COL2A1. Although the mutation is a variant of unknown significance, it is highly conserved and was predicted to be harmful by the SIFT and PolyPhen-2 software. In contrast to the control group, col2a1a mutation-expressing zebrafish larvae showed significant spinal curvature. Through preimplantation genetic testing for monogenic diseases excluding the missense mutation, a child conceived by ART was birthed with normal bone development.

CONCLUSION

We identified a de novo mutation in human COL2A1 related to lethal skeletal dysplasia and expanded the mutation spectrum of type II collagenopathies. In addition, we provided a new strategy based on a zebrafish model and ART for patients who harbour variants of unknown significance to have a healthy baby without genetic disease similar to the proband.