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Zhang Y, Deng L, Chen X, Hu Y, Chen Y, Chen K, Zhou J. Novel pathogenic OCRL mutations and genotype-phenotype analysis of Chinese children affected by oculocerebrorenal syndrome: two cases and a literature review. BMC Med Genomics 2021; 14:219. [PMID: 34488756 PMCID: PMC8422650 DOI: 10.1186/s12920-021-01069-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 08/27/2021] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Oculocerebrorenal syndrome of Lowe is a rare X-linked disorder characterized by congenital cataracts, mental retardation, and proximal tubulopathy. This condition is caused by a mutation of OCRL gene (located at chromosome Xq26.1), which encodes an inositol polyphosphate 5-phosphatase. CASE PRESENTATION We identified two novel OCRL mutations in two unrelated Chinese boys, each with a severe phenotype of Lowe syndrome. A novel de novo deletion (hemizygous c.659_662delAGGG, p.E220Vfs*29) was present in patient 1 and a novel splicing mutation (hemizygous c.2257-2A > T) that was maternally inherited was present in patient 2. A renal biopsy in patient 2 indicated mild mesangial proliferative glomerulonephritis, mild focal mononuclear cells infiltration, and interstitial focal fibrosis. Moreover, renal expression of OCRL-1 protein in patient 2 was significantly reduced compared to a control patient with thin basement membrane disease. CONCLUSIONS This study reports two novel OCRL variants associated with severe ocular and neurologic deficiency, despite only mild renal dysfunction. Based on our two patients and a literature review, the genotype-phenotype correlation of OCRL mutations with this severe phenotype of Lowe syndrome suggest a possible clustering of missense, deletion, and nonsense mutations in the 5-phosphatase domain and Rho-GAP domain in the Chinese population.
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Affiliation(s)
- Yu Zhang
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Ave., Wuhan, 430030, People's Republic of China
| | - Linxia Deng
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Ave., Wuhan, 430030, People's Republic of China
| | - Xiaohong Chen
- Department of Endocrinology and Metabolism, Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yingjie Hu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Ave., Wuhan, 430030, People's Republic of China
| | - Yaxian Chen
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Ave., Wuhan, 430030, People's Republic of China
| | - Kang Chen
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Ave., Wuhan, 430030, People's Republic of China
| | - Jianhua Zhou
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Ave., Wuhan, 430030, People's Republic of China.
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A novel CLCN5 mutation in a Chinese boy with Dent's disease. World J Pediatr 2014; 10:275-7. [PMID: 25124980 DOI: 10.1007/s12519-014-0504-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 01/28/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Dent's disease is a rare X-linked recessive hereditary disease caused by mutations in either the CLCN5 or OCRL1 genes. This disease is characterized by manifestations of proximal renal tubule dysfunction associated with low molecular weight proteinuria (LMWP), hypercalciuria, nephrocalcinosis, nephrolithiasis, and progressive renal failure. METHODS We report a Chinese boy with Dent's disease, clinically diagnosed by LMWP and hypercalciuria. Genetic analysis was made of the CLCN5 and OCRL1 genes. Related studies were also reviewed. RESULTS A splice site mutation IVS6, +2T>C of the CLCN5 gene was revealed in this case, and it was not reported previously. CONCLUSIONS Clinical and genetic analysis is valuable for the diagnosis of Dent's disease. A novel mutation in the CLCN5 gene was identified in our patient.
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Trésaugues L, Silvander C, Flodin S, Welin M, Nyman T, Gräslund S, Hammarström M, Berglund H, Nordlund P. Structural basis for phosphoinositide substrate recognition, catalysis, and membrane interactions in human inositol polyphosphate 5-phosphatases. Structure 2014; 22:744-55. [PMID: 24704254 DOI: 10.1016/j.str.2014.01.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 01/24/2014] [Accepted: 01/24/2014] [Indexed: 11/15/2022]
Abstract
SHIP2, OCRL, and INPP5B belong to inositol polyphosphate 5-phophatase subfamilies involved in insulin regulation and Lowes syndrome. The structural basis for membrane recognition, substrate specificity, and regulation of inositol polyphosphate 5-phophatases is still poorly understood. We determined the crystal structures of human SHIP2, OCRL, and INPP5B, the latter in complex with phosphoinositide substrate analogs, which revealed a membrane interaction patch likely to assist in sequestering substrates from the lipid bilayer. Residues recognizing the 1-phosphate of the substrates are highly conserved among human family members, suggesting similar substrate binding modes. However, 3- and 4-phosphate recognition varies and determines individual substrate specificity profiles. The high conservation of the environment of the scissile 5-phosphate suggests a common reaction geometry for all members of the human 5-phosphatase family.
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Affiliation(s)
- Lionel Trésaugues
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Camilla Silvander
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden.
| | - Susanne Flodin
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Martin Welin
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Tomas Nyman
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Susanne Gräslund
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Martin Hammarström
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Helena Berglund
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Pär Nordlund
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden; Division of Biophysics, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden; Centre for Biomedical Structural Biology, School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
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