Clinical features of Lowe syndrome and OCRL1 mutations in seven cases from six families / 中华肾脏病杂志

ABSTRACT

Objective:To explore the characteristics of Lowe syndrome, as well as OCRL1 gene mutation and its relationship with phenotype. Methods:Children diagnosed with Lowe syndrome during their visit to Nanfang Hospital of Southern Medical University (4 cases) and the First Affiliated Hospital of Sun Yat-sen University (3 cases) from January 2009 to January 2019 were included. The clinical data and peripheral blood samples were collected, and the sequence analysis of OCRL1 was performed after genomic DNA extraction. Then the clinical features of the children and the relationship between OCRL1 mutation and clinical phenotype were analyzed. Results:Seven patients from 6 families who presented with Lowe syndrome were included. All of them had different degrees of ocular-neural-renal symptoms. Six cases from 5 families had congenital cataract and neonatal hypotonia, one case from another family only had a thin lens without cataract. Four cases had nystagmus and 2 cases had glaucoma. Six cases from 6 families had psychomotor retardation and had proximal tubular impairment, included low-molecular-weight proteinuria (LMWP). Serum aspartate transaminase (AST), lactate dehydrogenase (LDH), creatine kinase (CK) and creatine kinase-MB (CK-MB) were increased in all 6 patients who were tested. Mutations of OCRL1 were detected in all the 6 families, which located in exon 10, 13, 16, 18, 22 and 23 respectively. The mutations of c.891 G>T, c.1682_1683insAA and c.2564_2567del are novel. Conclusions:Three OCRL1 novel mutations in 6 Chinese Lowe syndrome families are identified. The clinical manifestations in different mutations of OCRL1 are heterogeneous. The mutations of c.891 G>T in exon 10 without congenital cataract is rare in clinical.