Особенности патологии органа зрения при орфанном синдроме Pierson вследствие мутации гена LAMB2 у детей: обзор литературы и клиническое наблюдение

Abstract

Pierson syndrome is an orphan disease with an autosomal recessive mode of inheritance, characterized by combined pathology of the organ of vision, kidneys and central nervous system. Pierson syndrome is caused by a mutation in the LAMB2 gene, mapped on chromosome 3p21, encoding β2-laminin. The pathology of the organ of vision in Pierson syndrome in children is quite diverse. They are characterized by the presence of cataract, posterior lenticonus, iris hypoplasia, glaucoma, retinal detachment, etc. Microcoria (pupil diameter less than 2 mm) is also often observed due to atrophy of the pupillary dilator. The final diagnosis of Pierson syndrome can only be made based on the results of a molecular genetic study. Due to the severe lifethreatening renal manifestations of Pierson syndrome, for a long time the description of ophthalmological pathology was rather superficial. However, considering the high frequency and clinical severity of vision pathology in Pierson syndrome, it seems especially important to study in detail the features of the ocular phenotype in this disease. We have described a clinical observation of a child with Pierson syndrome, who was diagnosed with a missense mutation of the LAMB2 gene, a previously undescribed variant (rs143405268) in exon 18. The disease manifested itself as a combined pathology of the organ of vision, kidneys and the central nervous system. The ocular phenotype of the probands represented by microcoria, diffuse congenital cataract, and later by secondary glaucoma (after cataract surgery). Features of the renal phenotype of the proband were revealed – a horseshoe-shaped kidney, proteinuria not reaching the level of nephrotic syndrome, with preserved renal function. The peculiarity of this case of a child with Pierson syndrome is the absence of nephrotic syndrome in combination with the classic ocular phenotype with a previously undescribed variant of the LAMB2 gene mutation identified. Key words: pierson syndrome, LAMB 2, congenital cataract, microcoria, secondary glaucoma