Lowe syndrome

Lowe syndrome is a condition that primarily affects the eyes, brain, and kidneys. This disorder occurs almost exclusively in males.

Infants with Lowe syndrome are born with thick clouding of the lenses in both eyes (congenital cataracts), often with other eye abnormalities that can impair vision. About half of affected infants develop an eye disease called infantile glaucoma, which is characterized by increased pressure within the eyes.

Many individuals with Lowe syndrome have delayed development, and intellectual ability ranges from normal to severely impaired. Behavioral problems and seizures have also been reported in children with this condition. Most affected children have weak muscle tone from birth (neonatal hypotonia), which can contribute to feeding difficulties, problems with breathing, and delayed development of motor skills such as sitting, standing, and walking.

Kidney (renal) abnormalities, most commonly a condition known as renal Fanconi syndrome, frequently develop in individuals with Lowe syndrome. The kidneys play an essential role in maintaining the right amounts of minerals, salts, water, and other substances in the body. In individuals with renal Fanconi syndrome, the kidneys are unable to reabsorb important nutrients into the bloodstream. Instead, the nutrients are excreted in the urine. These kidney problems lead to increased urination, dehydration, and abnormally acidic blood (metabolic acidosis). A loss of salts and nutrients may also impair growth and result in soft, bowed bones (hypophosphatemic rickets), especially in the legs. Progressive kidney problems in older children and adults with Lowe syndrome can lead to life-threatening renal failure and end-stage renal disease (ESRD).

How common is Lowe syndrome?

Lowe syndrome is an uncommon condition. It has an estimated prevalence of 1 in 500,000 people.

What genes are related to Lowe syndrome?

Mutations in the OCRL gene cause Lowe syndrome. The OCRL gene provides instructions for making an enzyme that helps modify fat (lipid) molecules called membrane phospholipids. By controlling the levels of specific membrane phospholipids, the OCRL enzyme helps regulate the transport of certain substances to and from the cell membrane. This enzyme is also involved in the regulation of the actin cytoskeleton, which is a network of fibers that make up the cell's structural framework. The actin cytoskeleton has several critical functions, including determining cell shape and allowing cells to move.

Some mutations in the OCRL gene prevent the production of any OCRL enzyme. Other mutations reduce or eliminate the activity of the enzyme or prevent it from interacting with other proteins within the cell. Researchers are working to determine how OCRL mutations cause the characteristic features of Lowe syndrome. Because the OCRL enzyme is present throughout the body, it is unclear why the medical problems associated with this condition are mostly limited to the brain, kidneys, and eyes. It is possible that other enzymes may be able to compensate for the defective OCRL enzyme in unaffected tissues.

Read more about the OCRL gene.

How do people inherit Lowe syndrome?

This condition is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation must be present in both copies of the gene to cause the disorder. Most X-linked disorders affect males much more frequently than females. A striking characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.

In some cases of Lowe syndrome, an affected male inherits the mutation from a mother who carries one altered copy of the OCRL gene. Other cases result from new mutations in the gene and occur in males with no history of the disorder in their family.

Females who carry one mutated copy of the OCRL gene do not have the characteristic features of Lowe syndrome. Most female carriers, however, have changes in the lens of the eye that can be observed with a thorough eye examination. These changes typically do not impair vision.

What other names do people use for Lowe syndrome?

• Cerebrooculorenal Syndrome
• Lowe Oculocerebrorenal Syndrome
• Oculocerebrorenal Syndrome
• Oculocerebrorenal syndrome of Lowe
• Phosphatidylinositol-4,5-bisphosphate-5-phosphatase deficiency

Where can I find information about treatment for Lowe syndrome?

These resources address the management of Lowe syndrome and may include treatment providers.

• Gene Review: Lowe Syndrome
• MedlinePlus Encyclopedia: Congenital Cataract
• MedlinePlus Encyclopedia: Fanconi Syndrome

You might also find information on treatment of Lowe syndrome in Educational resources and Patient support.

Where can I find additional information about Lowe syndrome?

You may find the following resources about Lowe syndrome helpful. These materials are written for the general public.

• MedlinePlus - Health information (5 links)
• Educational resources - Information pages (3 links)
• Patient support - For patients and families (4 links)

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

• Gene Reviews - Clinical summary
• Gene Tests - DNA tests ordered by healthcare professionals
• ClinicalTrials.gov - Linking patients to medical research

PubMed - Recent literature

• Online Books - Medical and science texts
• Scriver's Online Metabolic and Molecular Bases of Inherited Disease (OMMBID): The Oculocerebrorenal Syndrome of Lowe (Lowe Syndrome)
• OMIM - Genetic disorder catalog

See How are genetic conditions and genes named? in the Handbook.

What if I still have specific questions about Lowe syndrome?

• See How can I find a genetics professional in my area? in the Handbook.
• Ask the Genetic and Rare Diseases Information Center.
• Submit your question to Ask the Geneticist.

Where can I find general information about genetic conditions?

The Handbook provides basic information about genetics in clear language.

• What does it mean if a disorder seems to run in my family?
• What are the different ways in which a genetic condition can be inherited?
• If a genetic disorder runs in my family, what are the chances that my children will have the condition?
• Why are some genetic conditions more common in particular ethnic groups?

These links provide additional genetics resources that may be useful.

• Genetics and health
• Resources for Patients and Families
• Resources for Health Professionals

What glossary definitions help with understanding Lowe syndrome?

acidosis ; actin ; carrier ; cataract ; cell ; cell membrane ; chromosome ; congenital ; cytoskeleton ; deficiency ; dehydration ; end-stage renal disease ; enzyme ; ESRD ; Fanconi syndrome ; gene ; glaucoma ; hypotonia ; inheritance ; kidney ; lipid ; mineral ; molecule ; motor ; motor skill ; muscle tone ; mutation ; neonatal ; new mutation ; phosphatase ; prevalence ; protein ; proximal ; renal ; renal disease ; rickets ; seizure ; sex chromosomes ; stage ; syndrome ; tissue ; trait

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

See also Understanding Medical Terminology.

References

• Attree O, Olivos IM, Okabe I, Bailey LC, Nelson DL, Lewis RA, McInnes RR, Nussbaum RL. The Lowe's oculocerebrorenal syndrome gene encodes a protein highly homologous to inositol polyphosphate-5-phosphatase. Nature. 1992 Jul 16;358(6383):239-42. PubMed citation
• Erdmann KS, Mao Y, McCrea HJ, Zoncu R, Lee S, Paradise S, Modregger J, Biemesderfer D, Toomre D, De Camilli P. A role of the Lowe syndrome protein OCRL in early steps of the endocytic pathway. Dev Cell. 2007 Sep;13(3):377-90. PubMed citation
• Gene Review: Lowe Syndrome
• Loi M. Lowe syndrome. Orphanet J Rare Dis. 2006 May 18;1:16. PubMed citation
• Lowe M. Structure and function of the Lowe syndrome protein OCRL1. Traffic. 2005 Sep;6(9):711-9. Review. PubMed citation