From Lowe syndrome to Dent disease: correlations between mutations of the OCRL1 gene and clinical and biochemical phenotypes.

Abstract

Mutations of OCRL1 are associated with both the Lowe oculocerebrorenal syndrome, a multisystemic and Dent-2 disease, a renal tubulopathy. We have identified a mutation in 130 Lowe syndrome families and 6 affected by Dent-2 disease with 51 of these mutations being novel. No founding effect was evidenced for recurrent mutations. Two mutations initially reported as causing Dent-2 disease were identified in patients, including two brothers, presenting with Lowe syndrome thus extending the clinical variability of OCRL1 mutations. mRNA levels, protein content, and PiP(2) -ase activities were analyzed in patient's fibroblasts. Although mRNA levels were normal in cells harboring a missense mutation, the OCRL1 content was markedly lowered, suggesting that enzymatic deficiency resulted mainly from protein degradation rather than from a catalytic inactivation. Analysis of a splicing mutation that led to the elimination of the initiation codon evidenced the presence of shortened forms of OCRL1 that might result from the use of alternative initiation codons. The specific mapping of the frameshift and nonsense mutations, exclusively identified in exons 1-7 and exons 8-23, respectively, for Dent disease and Lowe syndrome together with the possible use of alternative initiation codons might be related to their clinical expression, that is, Lowe syndrome or Dent-2 disease.

• Authors: Haifa Hichri, John Rendu, Nicole Monnier, Charles Coutton, Olivier Dorseuil, Rosa Vargas Poussou, Geneviève Baujat, Anne Blanchard, François Nobili, Bruno Ranchin, Michel Remesy, Rémi Salomon, Véronique Satre, Joel Lunardi
• Journal: Human mutation (Hum Mutat) Vol. 32 Issue 4 Pg. 379-88 (Apr 2011) ISSN: 1098-1004 [Electronic] United States
• PMID: 21031565 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2010 Wiley-Liss, Inc.

Chemical References

• CLC-5 chloride channel
• Chloride Channels
• RNA, Messenger
• Phosphoric Monoester Hydrolases
• OCRL protein, human

Topics

• Chloride Channels (genetics)
• DNA Mutational Analysis
• Dent Disease (genetics)
• Humans
• Male
• Mutation
• Oculocerebrorenal Syndrome (genetics)
• Phenotype
• Phosphoric Monoester Hydrolases (genetics)
• RNA, Messenger (metabolism)