Oculocerebrorenal Dystrophy (Lowe Syndrome)

Congenital cataracts a key symptom

Oculocerebrorenal dystrophy (OCRL), known as Lowe syndrome, is an inherited disorder linked to the X (female) chromosome. Most of the individuals affected by it, therefore, are male, since males have only one X chromosome. In order for a female to develop the syndrome, she would have to inherit the genetic defect on both of her X chromosomes. Thus, although OCRL can occur in females, it is a much less common occurrence.

Symptoms
There are three main symptoms which are present in all individuals with OCRL:

• Cataracts in one or both eyes at birth
• Low muscle tone and weakness (hypotonia)
• Kidney dysfunction - the kidneys may functions normally at birth, but abnormal function is present often by 1 year old.

In addition, individuals may have symptoms such as:

• Mental retardation - About 10% of individuals with OCRL have IQs near low normal (70), about 33% have very low IQs, with most individuals having moderate low IQs (40-54). This does not change over time.
• Seizures - occur in about 50% of individuals with OCRL, usually in young children with the syndrome
• Behavior problems
• Glaucoma - 50-60% of individuals have glaucoma, often in both eyes
• Bone weakness - Many individuals with OCRL have bone fractures, especially in the leg bones when learning to walk. About one-third of individuals have more than one fracture.
• Undescended testicles in boys.

Diagnosis
Oculocerebrorenal dystrophy is usually diagnosed at birth or in early infancy based on physical symptoms, in particular cataracts in the eyes and muscle weakness. Lab tests can check how the kidneys are functioning.

Treatment
Medical care focuses on managing the kidney problems that develop. The eye cataracts are surgically removed as soon as possible, even before the infant is one month old, so that the visual parts of the brain can develop normally. Physical, occupational, and speech therapies can help individuals reach their individual potentials for development.

Genetic counseling
Since oculocerebrorenal dystrophy is an X-linked disorder, this means that if a child has the disorder, his mother is a carrier. Female carriers can be detected through eye examination, since most have some type of eye abnormality characteristic of OCRL. Each male child of a female who carries the disorder will have a 50% chance of developing OCRL, and each female child will have a 50% chance of being a carrier.

Information for this article was taken from:
Wasserstein, M. (2003). Oculocerebrorenal dystrophy (Lowe syndrome). eMedicine, accessed at http://www.emedicine.com/ped/topic1329.htm