Comparative Study On Imaging Features Of Familial Carpal Tunnel Syndrome Caused By COMP Mutation

Background and objective:In the past,carpal tunnel syndrome（CTS）was considered as sporadic or accompanied by other systemic diseases until some scholars first proposed the concept of familial carpal tunnel syndrome（FCTS）in 1969.Li Chunyu reported a FCTS family with 6 generations and 11 people in 2004.Through genome-wide association study and targeted sequencing analysis,the pathogenic gene of the family was determined because of the COMP gene:cartilage oligomeric matrix protein.The purpose of this paper is to clarify whether there are significant differences in the morphological structure of ligaments,tendons and carpal tunnel contents between familial CTS patients caused by COMP mutation and normal people in their families,and to verify and discuss the participation mechanism and important role of COMP in the occurrence and development of FCTS.Method:FCTS patients whose hands were not suitable for hand surgery clinic in China-Japan Union Hospital of Jilin University since 2004 were selected and included in the experimental group（n=17）.All individuals came from the same family,and COMP mutation was confirmed by gene detection technology.Normal adults from the above families,excluding COMP mutation by gene detection technology and without CTS symptoms,were included in the control group（n=10）.The general data of the two groups were collected,including age,gender and detailed medical history.The wrist and ankle of the two groups were examined by 3.0T MRI.The cross-sectional area of median nerve（CSA）,cross-sectional area of carpal tunnel（CSAc）,total cross-sectional area of tendon in carpal tunnel（CSAt）and thickness of the transverse carpal ligament（TTCL）were measured,and the volume ratio of tendon to carpal tunnel（R = CSAt / CSAc×100%）;The cross-sectional area of flexor pollicis longus tendon（CSAf）at the level of the first metacarpophalangeal joint was measured;The cross-sectional area of Achilles tendon（CSAa）in the distal plane of the ankle was measured.SPSS was used to statistically analyze the above indexes,compare the differences between the two groups,and analyze the correlation between CSAt and CSAa in the experimental group.Result:In the comparison of general data,there was no significant difference in gender and age between the two groups（P > 0.05）.In the comparison of MRI related data,except CSAa（P > 0.05）,the differences of other indexes between the two groups were statistically significant（P < 0.05）.CSA in the experimental group was significantly lower than that in the control group,and TTCL,CSAt,R and CSAf in the experimental group were significantly higher than those in the control group.The correlation analysis between CSAt and CSAa in the experimental group showed a significant positive correlation（correlation coefficient r > 0.8,P < 0.001）.Conclusions:1.FCTS patients caused by comp gene mutation have significant changes in the morphology and structure of transverse carpal ligament and carpal tunnel contents（median nerve and flexor tendon）.2.The effect of COMP mutation on patients is not only limited to median nerve compression,leading to carpal tunnel syndrome,but also may have systemic lesions of connective tissue.