Macular Corneal Dystrophy In A Consanguineous Marriage Chinese Family Related With Novel Mutations Of CHST6

Objective: This experiment selected central China incest porphyritic corneal malnutrition family study.It was to study the relations betwwen inbreeding porphyritic corneal malnutrition family with CHST6 gene mutations and to study the histopathological changes.Methods: Selecting the central China a incest porphyritic corneal malnutrition genealogy, 8 people of the family living, which found that 2 patients, including 1 male and female patients. The porphyritic malnutrition all members of the cornea were inquiried detailed history, examined strictly eye specialist inspection. Patients pathological changes of cornea histopathological examination, used standard methods HE staining。5 ml of peripheral blood were Collected of seven members, extracted of genomic DNA.CHST6 gene have four exons,and encoding area located on the third exons and polymerase chain reaction(PCR) was applied to CHST6 gene coding region of gene amplification for sequencing, then compareed CHST6 sequencing results with the gene pool of a normal population. Propositus was took " Cornea lesion resection and amniotic membrane transplantation of right eye", used the intraoperative corneal tissue after resection, organization was blocked,conventional paraffin embedd, and then cut it into 4 microns section. After HE staining and conventional dehydration, specimen was transparent, then sealed. Samples was undertook pathological examination after HE staining.Results: All members of the family were examined by strict eye check specialistly, including visual acuity, slit-lamp examination, anterior segment photographic, and so on。 And all of the family members of CHST6 gene coding region of positive and negative two-way were sequenced. Sequencing results in 2 patients of two equipotential CHST6 gene exists in the same point mutations c. 1072 t > c(Y358H), other people in normal phenotype and related with the proband are carriers of the mutation. Confocal microscopy tips stromal layer contains large amounts of turbid substance accumulation, patch shape distribution of matrix fiber fracture, partly dissolved, stromal cells decreases. Histopathology found propositus corneal tissue pale with thin corneal stroma, organization was relatively loose, matrix collagen disorganized, there were a large number of abnormal amyloid deposits. A lot of pink material deposition in corneal stroma were found after HE staining. Matrix fiber was disordered arrangement and fracture,dyed red.Conclusion: This study confirmed that consanguineous marriage family in 2 patients to two bit CHST6 gene has same point mutation(1072T>C), genotype homozygous recessive and the other family members were for of gene carriers 1072T>C point mutation. The homozygous recessive mutation is a direct cause of the macular corneal dystrophy, corneal opacity, so far, in the domestic and foreign research has not yet found the homozygous recessive mutation type.