Mucolipidoi IV: Report of a Cae with Ocular Retricted Phenotype Caued by Leaky plice Mutation Original Reearch Article

Purpoe To confirm and define a molecular bai for a cae of mucolipidoi type IV (ML IV) with an extremely atypical phenotype pattern. Deign Obervational cae report of a patient with ML IV with dieae progreion retricted to ocular ymptom. Method Complete ophthalmologic and neurologic examination. Ultratructural examination of white blood cell, kin, conjunctiva, and corneal epithelium. The MCOLN1 gene wa equenced from cDNA and the proportion of plicing variant were aeed by quantitative allele-pecific polymerae chain reaction. Reult Abence of any neurological abnormalitie. Retinal pathologic feature were the main caue of viual diability: low viual acuity and cloudy cornea ince 2 year of age, progreive decreae in viual acuity ince the age of 9 year. Ultratructural examination howed torage lyoome filled with either concentric membrane or lucent precipitate in corneal and conjunctive epithelia and in vacular endothelium. Cultured fibroblat were free of any autofluorecence. equencing of the MCOLN1 gene identified compound heterozygoity for D362Y and A→T tranition leading to the creation of a novel donor plicing ite and a 4-bp deletion from exon 13 at the mRNA level. Both normal and pathologic plice form were detected in kin fibroblat and leukocyte, with the normal form being more abundant. Concluion The cae of thi patient with ML IV i unique and i characterized by a curiou lack of generalized ymptom. In thi patient, the diorder wa limited to the eye and appeared without the uual pychomotor deterioration. The reulting phenotype i the mildet een to date.