Oculocerebrorenal syndrome

Oculocerebrorenal syndrome
Classification and external resources
ICD-10	E72.0
ICD-9	270.8
OMIM	309000
DiseasesDB	29146
eMedicine	oph/516
MeSH	D009800

Oculocerebrorenal syndrome (also called Lowe syndrome) is a X-linked recessive disorder characterized by hydrophthalmia, cataracts, intellectual disabilities, aminoaciduria, reduced renal ammonia production and vitamin D-resistant rickets.

Lowe syndrome can be considered a cause of Fanconi syndrome.^[1]

Lowe Syndrome (LS) is a rare genetic condition that causes physical and mental handicaps, and medical problems.

History

It was first described in 1952 by Drs. Lowe, Terrey, and MacLachlan at the Massachusetts General Hospital in Boston.

The condition became known as "Lowe syndrome" named after Dr. Charles Lowe, the senior member of the group that described it. Because of the three major organ systems involved (eyes, brain, and kidney), it is also known as OCRL (oculo-cerebro-renal) syndrome.

Presentation

Boys with Lowe Syndrome are born with cataracts in both eyes, which are usually removed at a few months of age. Most boys are fitted with glasses, contact lenses, or a combination of the two. Glaucoma is present in about 50% of the boys with Lowe syndrome, though usually not at birth. Prescription eye drop and/or surgery is required to maintain appropriate eye pressure in these cases.

While not present at birth, many Lowe Syndrome boys develop kidney problems at approximately one year of age. This is characterized by the abnormal loss of certain substances into the urine, including bicarbonate, sodium, potassium, amino acids, organic acids, albumin and other small proteins, calcium, phosphate, glucose, and L-carnitine. This problem is known as Fanconi-type renal tubular dysfunction and can also be seen in certain other diseases and syndromes. In Lowe syndrome, the Fanconi syndrome may be mild and involve only a few substances or may be severe and involve large losses of many substances. Medications can be prescribed to replace the lost substances.

Cause

Lowe syndrome is a "genetic" condition (i.e. occurs from birth, due to a gene mutation that may not have any family history, or may be hereditary) and affects mainly males. It is caused by a single defective gene (an alteration or "mutation") in a gene called OCRL1. Because of this defective gene, an essential enzyme called PIP2-5-phosphatase is not produced. This is the underlying cause of Lowe syndrome.

The gene has been mapped and the deficient enzyme has been identified, although its role is not fully understood. Today there is no correlation between the gene mutation, the level of enzyme deficienty and the symptoms. Other Syndromes such as Dents, may have almost identical mutations but while exhibiting some symptoms such as kidney disorders, do not have the enzyme deficiency or other symptoms such as cataracts.

Much research has taken place in the last few years, but the diagnosis is still largely clinical, based on cataracts at birth in both eyes and a kidney disorder, plus a positive test for the enzyme deficiency.

Eponym

It is named for Charles Upton Lowe (August 24,1921- ).^[2][3]

References

1. ^ Vilasi A, Cutillas PR, Maher AD, et al. (August 2007). "Combined proteomic and metabonomic studies in three genetic forms of the renal Fanconi syndrome". Am. J. Physiol. Renal Physiol. 293 (2): F456–67. doi:10.1152/ajprenal.00095.2007. PMID 17494094. http://ajprenal.physiology.org/cgi/pmidlookup?view=long&pmid=17494094. 
2. ^ synd/3512 at Who Named It?
3. ^ Lowe CU, Terrey M, MacLachlan EA (1952). "Organic-aciduria, decreased renal ammonia production, hydrophthalmos, and mental retardation; a clinical entity". A.M.A. American journal of diseases of children 83 (2): 164–84. PMID 14884753. 

External links

• Lowe Syndrome Association Official Website
• U.K. Lowe Syndrome Trust
• GeneReview/NIH/UW entry on Lowe Syndrome
• Asociación Española de Síndrome de Lowe