Oculocerebrorenal Syndrome Workup
- Author: Deborah M Alcorn, MD; Chief Editor: Hampton Roy Sr, MD more...
Laboratory Studies
- Serum
- Elevated serum enzyme levels
- Enzyme test (phosphatidylinositol-4,5-bisphosphate phosphatase; >99% sensitivity) in males who are affected
- Mild elevations of aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and creatine phosphokinase (CPK)
- Increased serum glutamic-oxaloacetic transaminase (SGOT) and lactate dehydrogenase (LDH)
- Serum protein electrophoresis shows a markedly elevated alpha-2-band, and total serum protein concentration is elevated frequently in patients older than 4 years.
- Acid phosphatase is elevated in most patients.
- Increased alkaline phosphatase
- Increased creatinine
- Hypokalemia
- Urinalysis
- Check for reducing substances
- Low urine osmolality and elevated 24-hour volumes
- Proteinuria
- Aminoaciduria
- Hyperphosphaturia, frequently present, but may be variable
- Calciuria
- Check urine ph
- Check L-carnitine (may be lost in urine)
- Blood gas - Metabolic acidosis secondary to urinary loss of bicarbonate
Imaging Studies
- Ocular ultrasound: B-scan is indicated if posterior pole cannot be visualized secondary to the cataract.
- Cranial MRI: Mild ventriculomegaly is evident in about one third of patients. Additionally, in a periventricular and centrum semiovale distribution, increased signal intensity may occur on T2-weighted scans. These areas correspond to cysts of variable size and number and are yet of no known clinical significance.
Other Tests
- Ocular evaluation to assess possible carrier status. Slit lamp examination of the biological mother's lenses or females at risk to assess if any lenticular opacities
- DNA testing
- DNA carrier testing for familial mutation (requires prior identification of unique mutation of OCRL1 gene in that family)
- OCRL1 gene mutation analysis (approximately 90% sensitivity for males who are affected)
Histologic Findings
Renal histology usually is normal in utero and in neonates. However, within the first few months of life, these infants may show tubular abnormalities with dilation, atrophy, and accumulation of proteinaceous material in the tubular lumens. Young infants usually have normal glomeruli, but, after a few years, they may manifest glomerular lesions with sclerosis, focal fibrosis, and thickening of basement membranes.
Lowe CU, Terrey M, MacLachlan EA. Organic-aciduria, decreased renal ammonia production, hydrophthalmos, and mental retardation. Am J Dis Child. 1952;83:164-184.
Loi M. Lowe syndrome. Orphanet J Rare Dis. May 18 2006;1:16. [Medline].
Walton DS, Katsavounidou G, Lowe CU. Glaucoma with the oculocerebrorenal syndrome of Lowe. J Glaucoma. Jun 2005;14(3):181-5. [Medline].
Attree O, Olivos IM, Okabe I, Bailey LC, Nelson DL, Lewis RA. The Lowe's oculocerebrorenal syndrome gene encodes a protein highly homologous to inositol polyphosphate-5-phosphatase. Nature. Jul 16 1992;358(6383):239-42. [Medline].
Cibis GW, Waeltermann JM, Whitcraft CT, Tripathi RC, Harris DJ. Lenticular opacities in carriers of Lowe's syndrome. Ophthalmology. Aug 1986;93(8):1041-5. [Medline].
Kenworthy L, Charnas L. Evidence for a discrete behavioral phenotype in the oculocerebrorenal syndrome of Lowe. Am J Med Genet. Nov 20 1995;59(3):283-90. [Medline].
Kruger SJ, Wilson ME Jr, Hutchinson AK, Peterseim MM, Bartholomew LR, Saunders RA. Cataracts and glaucoma in patients with oculocerebrorenal syndrome. Arch Ophthalmol. Sep 2003;121(9):1234-7. [Medline].
Lavin CW, McKeown CA. The oculocerebrorenal syndrome of Lowe. Int Ophthalmol Clin. Spring 1993;33(2):179-91. [Medline].
Lin T, Lewis RA, Nussbaum RL. Molecular confirmation of carriers for Lowe syndrome. Ophthalmology. Jan 1999;106(1):119-22. [Medline].
Nussbaum RL, Orrison BM, Janne PA, Charnas L, Chinault AC. Physical mapping and genomic structure of the Lowe syndrome gene OCRL1. Hum Genet. Feb 1997;99(2):145-50. [Medline].
Suchy SF, Nussbaum RL. The deficiency of PIP2 5-phosphatase in Lowe syndrome affects actin polymerization. Am J Hum Genet. Dec 2002;71(6):1420-7. [Medline].
Tripathi RC, Cibis GW, Tripathi BJ. Pathogenesis of cataracts in patients with Lowe's syndrome. Ophthalmology. Aug 1986;93(8):1046-51. [Medline].
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