Gene Mapping, Clinical Classification And Resting State Functional Magnetic Resonance Imaging(rs-fMRI) In The Patients With Congenital Fibrosis Of The Extraocular Muscles(CFEOM)

Objectives:To determine the pathogenic mutant gene and the classification of CFEOM parentages from China and to study the changes of the function of these patients’ s brains, for understanding this nerve source disease furtherly and its rules of fMRI(CNS) in primary studies.Methods:1. Gene sequencing and disease classification1.1 Nine patients with CFEOM in 2 parentages from China were collected and underwent for data: medical history, examination and 5-8ml from peripheral venous blood(for DNA). First we detected the dominant mutant genes of CFEOM, taking direct DNA sequence analysis, confirmed by SSCP. Then we selected 100 healthy and unrelated Chinese people randomly as control group to exclude the gene polymorphism. If it were failed, we would researched to the other gene mutations that had been reported up to now, or using linkage analysis and whole exon sequencing for further explorion.1.2 The disease classification of CFEOM family patients would be come up with according to the clinical phenotype and the pathogenic mutant gene we determined.2. Nerve function test and analysisResting state functional magnetic resonance imaging(re-fMRI) and 3D brain imaging were performed in patients and healthy control subjects, which matched by the proportion of 2:1 according to age and sex.2.1 All subjects were underwent the whole brain conventional axial MRI scan to exclude brain organic disease and rs-fMRI scan.2.2 rs-fMRI scan:Real time Imaging Processing(RTIP) and Echo-Planar Imaging Gradient-Recalled(GRE-EPI) sequences and real time imaging(Real-Time) were used.2.3 Observation indexs and analysis:The data were preprocessed and correctedby RESET software, andanalysedby SPM8 software. The low frequency amplitude(ALFF), local consistency(ReHo), functional connectivity(FC), voxel-based morphometry(VBM) of patients group and healthy controls(HCs) group were compared and analyzed.Results:1. Clinical research1.1 9 patients in Family1 have the typical CFEOM characteristic. The mutation site was located in KIF21A(Exon 21), 2860C>T(R954W), which was heterozygous missense mutation.1.2 4 patients in Family2 have the typical CFEOM appearance characteristics except 1 patient. The mutation site was located in TBUU3(Exon 4), 1249G>A(D417N), which was also heterozygous missense mutations.1.3 The central nervous system MRI of all patients were no obvious dysplasia in morphology.2. rs-fMRI research2.1 The results of resting state on the whole brainPatients group included 6 males and 2 females with average age 35.38±14.02(13-58 years). HCs group included 12 males and 4 females with average age 36.26±15.64(12-58 years). There was no significant difference between the two groups according to age.2.1.1 ALFF: compared with HCs group, patient’s brain areas with enhanced ALFF were tonsil of cerebellum, left inferior temporal gyrus and with weakened change was right on top of the lobules.2.1.2 ReHo: compared with HCs group, patient’s brain areas with enhanced ReHo were right parietal lobe, left lingual gyrus, left insular central sulcus, right middle frontal gyrus and with weakened change was left posterior cerebellar lobe.2.1.3 FC: compared with HCs group in the right middle frontal gyrus seed regions of interest(ROI), there were no increase changes of brain areas in the patients and the weakened regions were right postcentral gyrus and left superior parietal lobule. In the left middle frontal gyrus seed regions of interest(ROI), there were no increase brain areas, while increased brain areas were right cerebellum anterior lobe and cerebellar vermis.2.2 VBM analysis of the whole brain gray and the white matter volume2.2.1 The gray matter volume: compared with the HCs group, the increased gray matter volume of brain regions in patients group: the left supplementary motor area, right inferior parietal lobule, right inferior frontal gyrus orbital and the reduced volume of the region: right inferior frontal gyrus and left superior frontal gyrus.2.2.2 The white matter volume: compared with the HCs group, there was no increased white matter volume in patients group; and the reduced brain regions: the left thalamus, right inferior occipital gyrus, the right amygdala, corpus callosum splenium, parietal lobe of the right angular gyrus and right superior temporal gyrus.Conclusion:1. The mutation site of the CFEOM Family 1 was KIF21 A, 2860C>T(R954W), and that of the Family 2 was TBUU3, 1249G>A(D417N), which were all heterozygous missense mutations.2. The CFEOM 1 and CFEOM 3 had the same clinical manifestations, while the phenotype of the latter was diverse and uncompleterate. Family 1 was CFEOM 1A, with complete penetrance and autosomal dominant inheritance. Family 2 was CFEOM 3A, with incomplete penetrance and autosomal dominant inheritance.3. The CNS MRI of these CFEOM patients showed no obvious dysplasia in morphology.4. The whole brain fMRI show that CFEOM patients had many changes in the some central signal sequence, indicating the functions of relevant brain areas varing on the aspects of mental and emotional, understanding and identification, movement and control. The functional connectivity abnormalities of the BA8 region in different hemispheres were related to the parietal lobe and cerebellum, which were related to visual perception, motor learning and environment adaptation.5. The wide range of gray and white matter volumehas changed in patients with CFEOM, which involving a number of central nervous function area and the edge of the cortex and subcortical structures. The white matter has a broad volume reducted areas in accordance with the characteristics of central nervous system, which suggesting it were a kind of CNS dysfunction desease.