Genetic localization and clinical classification of congenital fibrosis of the extraocular muscles in 2 Chinese families / 眼科新进展

Objective To determine the pathogenic mutant gene and the classification for 2 Chinese families with congenital fibrosis of the extraocular muscles (CFEOM) by using candidate genes methods.Methyls All members in the 2 Chinese families with CFEOM were collected and underwent for clinical data collection,including medical history,physical examination and 5-8 mL peripheral venous blood for DNA extraction.Exon 2,8,20,21 of KIF21A,exon 1,2,3 of PHOX2A/ARIX,exon 1,2,3,and 4 of TUBB2B and exon 1,2,3,4 of TUBB3 were selected and synthesized by PCR,and the amplified samples were purified for sequences analysis by Chromas2.3 and DNAman7.0 software.Results There were 9 members developed CFEOM in family 1,with the typical CFEOM characteristics.The mutation site was located in KIF21A (exon 21),2860C ＞ T;and 4 patients in family 2 suffered this disease,and the typical CFEOM appearance features was in 3 patients.The mutation site was located in TBUU3 (exon 4),1249 G ＞ A.Conclusion The candidate genes methods can be used to identify the pathogenic genes of pedigrees with inherited diseases effectively.Family 1 belongs to CFEOM 1A type,which is the autosomal dominant inheritance with complete penetrance,and family 2 belongs to CFEOM 3A type,whivh is the autosomal dominant inheritance with incomplete penetrance.

Imaging of Cranial Nerves III, IV, VI in Congenital Cranial Dysinnervation Disorders

Congenital cranial dysinnervation disorders are a group of diseases caused by abnormal development of cranial nerve nuclei or their axonal connections, resulting in aberrant innervation of the ocular and facial musculature. Its diagnosis could be facilitated by the development of high resolution thin-section magnetic resonance imaging. The purpose of this review is to describe the method to visualize cranial nerves III, IV, and VI and to present the imaging findings of congenital cranial dysinnervation disorders including congenital oculomotor nerve palsy, congenital trochlear nerve palsy, Duane retraction syndrome, Möbius syndrome, congenital fibrosis of the extraocular muscles, synergistic divergence, and synergistic convergence.

MRI demonstrates abnormalities of motor nerves and extraocular muscles in congenital fibrosis syndrome due to mutations in KIF21 A / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To observe the structural basis of ocular motility abnormalities in patients with congenital fibrosis of the extraocular muscles type Ⅰ ( CFEOM Ⅰ) due to missense mutations in the developmental kinesin KIF21A using high - resolution magnetic resonance imaging ( MRI) . METHODS: Totally 11 affected individuals reported KIF21A mutations were correlated with MRI studies demonstrating extraocular muscles ( EOMs ) size, location, contractility, and innervation. EOMs and the motor nerve in the orbits were imaged with T1 weighted in a triplanar scan using a dual-phased coils with 2. 0mm thick. Motor nerves were imaged at the brainstem using head coils and 3D-FIESTA with 0. 6-mm thick. RESULTS: Patients with CFEOM Ⅰ exhibited different degrees of hypoplasia of oculomotor nerve, the abducens nerve and the trochlear nerve were also affected, of which 8 cases of orbital section could see the signal of abnormal nerve dominated by oculomotor nerve to lateral rectus. The both sides of six EOMS in all patients exhibited variable atrophy and abnormal bright internal signal on T1 imaging, particularly severe for the superior rectus and levator muscles. CONCLUSION: High - resolution MRI can directly demonstrate pathology of motor nerves,affected EOMs, and ‘Pulley' hypoplasia caused by CFEOM Ⅰ due to mutations in KIF21A,and these findings suggest that the neuronal hypoplasia is the etiological factor of CFEOM.