OCRL Gene

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).

Dent disease is a chronic kidney disorder that occurs almost exclusively in males. In affected individuals, kidney problems result from damage to structures called proximal tubules. Signs and symptoms of this condition appear in early childhood and worsen over time.

The most frequent sign of Dent disease is the presence of an abnormally large amount of proteins in the urine (tubular proteinuria). Other common signs of the disorder include excess calcium in the urine (hypercalciuria), calcium deposits in the kidneys (nephrocalcinosis), and kidney stones (nephrolithiasis). Kidney stones can cause abdominal pain and blood in the urine (hematuria). In most affected males, progressive kidney problems lead to end-stage renal disease (ESRD) in early to mid-adulthood. ESRD is a life-threatening failure of kidney function that occurs when the kidneys are no longer able to filter fluids and waste products from the body effectively.

Some people with Dent disease develop rickets, a bone disorder that results when the levels of vitamin D and certain minerals (including calcium) in the blood become too low. Rickets can be associated with weakening and softening of the bones, bone pain, bowed legs, and difficulty walking.

Researchers have described two forms of Dent disease, which are distinguished by their genetic cause and pattern of signs and symptoms. Both forms of Dent disease (type 1 and type 2) are characterized by the features described above, but Dent disease 2 can also be associated with abnormalities unrelated to kidney function. These additional signs and symptoms include mild intellectual disability, weak muscle tone (hypotonia), and clouding of the lens of the eyes (cataract) that is described as subclinical because it does not impair vision. Some researchers consider Dent disease 2 to be a mild variant of a similar disorder called Lowe syndrome.