Screening for SH3TC2, PMP2, and BSCL2 Variants in a Cohort of Chinese Patients with Charcot-Marie-Tooth.

BACKGROUND: SH3TC2, PMP2, and BSCL2 genes are related to autosomal recessive (AR) Charcot-Marie-Tooth (CMT) disease type 1, autosomal dominant (AD)-CMT1, and AD-CMT2, respectively. Pathogenic variants in these three genes were not well documented in Chinese CMT patients. Therefore, this study aims to detect SH3TC2, PMP2, and BSCL2 pathogenic variants in a cohort of 315 unrelated Chinese CMT families. METHODS: A total of 315 probands from 315 unrelated Chinese CMT families were recruited from the Department of Neurology of Third Xiangya Hospital and Xiangya Hospital. We screened for SH3TC2 pathogenic variants in 84 AR or sporadic CMT probands, PMP2 pathogenic variants in 39 AD or sporadic CMT1 probands, and BSCL2 pathogenic variants in 50 AD or sporadic CMT2 probands, using polymerase chain reaction and Sanger sequencing. All these patients were out of 315 unrelated Chinese CMT families and genetically undiagnosed after exclusion of pathogenic variants of PMP22, MFN2, MPZ, GJB1, GDAP1, HSPB1, HSPB8, EGR2, NEFL, and RAB7. Candidate variants were analyzed based on the standards and guidelines of American College of Medical Genetics and Genomics (ACMG). Clinical features were reevaluated. RESULTS: We identified three novel heterozygous variants such as p.L95V (c.283C>G), p.L1048P (c.3143T>C), and p.V1105M (c.3313G>A) of SH3TC2 gene and no pathogenic variants of PMP2 and BSCL2 genes. Although evaluation in silico and screening in the healthy control revealed that the three SH3TC2 variants were likely pathogenic, no second allele variants were discovered. According to the standards and guidelines of ACMG, the heterozygous SH3TC2 variants such as p.L95V, p.L1048P, and p.V1105M were considered to be of uncertain significance. CONCLUSIONS: SH3TC2, PMP2, and BSCL2 pathogenic variants might be rare in Chinese CMT patients. Further studies to confirm our findings are needed.

[Mechanism of catalytic ozonation for the degradation of paracetamol by activated carbon].

The degradation of paracetamol (APAP) in aqueous solution was studied with ozonation integrated with activated carbon (AC). The synergistic effect of ozonation/AC process was explored by comparing the degradation efficiency of APAP in three processes (ozonation alone, activated carbon alone and ozonation integrated with activated carbon). The operational parameters that affected the reaction rate were carefully optimized. Based on the intermediates detected, the possible pathway for catalytic degradation was discussed and the reaction mechanism was also investigated. The results showed that the TOC removal reached 55.11% at 60 min in the AC/O3 system, and was significantly better than the sum of ozonation alone (20.22%) and activated carbon alone (27.39%), showing the great synergistic effect. And the BOD5/COD ratio increased from 0.086 (before reaction) to 0.543 (after reaction), indicating that the biodegradability was also greatly improved. The effects of the initial concentration of APAP, pH value, ozone dosage and AC dosage on the variation of reaction rate were carefully discussed. The catalytic reaction mechanism was different at different pH values: the organic pollutions were removed by adsorption and direct ozone oxidation at acidic pH, and mainly by catalytic ozonation at alkaline pH.