Lowe syndrome is an X-linked recessive disease characterized by profound mental retardation, cataracts, and renal abnormalities.
The cataract is the first obvious symptom in patients with Lowe syndrome. It is present at birth already. Later on patient can develop glaucoma and nystagmus.
Although 25% of patient may have low normal intelligence, most of them show clear intellectual impairment. Also observed are areflexia and developmental delay. Some infants develop seizures.
Kidney dysfunktion is not as obvious in the first place. it is normal at birth. By the first year of life, however, patients develop proximal dysfunction which includes proteinuria, aminoaciduria (characteristically sparing branched-chain amino acids), variable glucosuria, and phosphaturia. Some patients develop hypophosphatemic rickets and neophrcalcinosis. Proteinuria is to blame for progressive renal failure which in the forties leads to end stage renal failure.
The diagnosis is made by the typical clinical findings. There is no specific laboratory finding in patients with Lowe syndrome, so the clinical diagnosis can be confirmed by molecular genetic diagnostics only. The latter, by providing the molecular cause, offers the possibility of prenatal diagnosis.
Along with urinary abnormalities that include proteinuria, phosphaturia, glycosuria, and amino aciduria, elevated serum creatine kinase, lactate dehydrogenase, and total serum protein are observed.
Treatment is symptomatic and supportive. It includes electrolyte, bicarbonate, and vitamin D supplementation. Infants get operated on cataract. Some receive antiepileptics. At some stage renal failure requires a replacement therapy.
Suchy SF et al. (2002) The deficiency of PIP2 5-phosphatase in Lowe syndrome affects actin polymerization.[^]
Pendaries C et al. (2003) Phosphoinositide signaling disorders in human diseases.[^]
Faucherre A et al. (2003) Lowe syndrome protein OCRL1 interacts with Rac GTPase in the trans-Golgi network.[^]
AURICCHIO S et al. (1961) [Primary tubulopathies. III. A case of oculo-cerebro-renal syndrome (Lowe syndrome)][^]
Faucherre A et al. (2005) Lowe syndrome protein Ocrl1 is translocated to membrane ruffles upon Rac GTPase activation: a new perspective on Lowe syndrome pathophysiology.[^]
Choudhury R et al. (2005) Lowe syndrome protein OCRL1 interacts with clathrin and regulates protein trafficking between endosomes and the trans-Golgi network.[^]
Lowe M et al. (2005) Structure and function of the Lowe syndrome protein OCRL1.[^]
Loi M et al. (2006) Lowe syndrome.[^]