LOWE SYNDROME

ALTERNATE NAMES

LS; Cerebro-oculo-renal Syndrome; Cerebro-oculo-renal Dystrophy; Lowe Oculocerbrorenal Syndrome; Lowe’s Disease; Oculocerebrorenal Dystrophy; OCRL; Oculocerebrorenal Syndrome; OCR; Oculo-cerebrorenal Syndrome of Lowe; Phosphatidylinositol-4,5 Bisphospate-5-Phosphatase Deficiency

DESCRIPTION

Lowe Syndrome (LS) is a rare genetic condition caused by a mutation in the OCRL 1 gene resulting in physical and mental impairments beginning at birth. Because of this defective gene, an essential enzyme called PIP2-5 phosphatase is not produced. This enzyme is essential to normal metabolic processes that take place in a small part of the cell called the Golgi apparatus. Because of the enzyme deficiency, cell functions that are regulated by the Golgi are abnormal, leading to various developmental defects including bilateral cataracts and impairments of the nervous system and kidneys.

This disorder occurs most often in males, but can also occur in females. There are three main findings, which are present in all people with LS: cataracts in one eye or both eyes at birth (glaucoma is present in about 50 percent of cases, though usually not at birth); low muscle tone and weakness (hypotonia) at birth; and Fanconi syndrome, which is a type of kidney dysfunction. People with Fanconi syndrome generally have normal kidney function shortly after birth, but abnormal function occurs by 1 year of age.

The kidneys play an important role in maintaining chemical balance in the body. In people with renal Fanconi syndrome, the kidneys are unable to reabsorb important nutrients into the bloodstream. When there is an imbalance of salts, minerals, water and other substances in the body, this imbalance can lead to impaired growth, bowed leg bones (hypophosphatemic rickets), and progressively worsening and life-threatening renal failure (end-stage renal disease).

In addition to kidney dysfunction, children with LS have other impairments such as intellectual disability, seizures, behavior problems, glaucoma, bone weakness (neonatal hypotonia), and, in male children, undescended testicles. Neonatal hypotonia can contribute to feeding difficulties, problems with breathing, and delayed development of motor skills (i.e. sitting, standing, and walking). Motor and mental developmental delays are generally present in infancy. Temper tantrums and aggressiveness are frequent during adolescence.

DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND ICD-9-CM CODING

Molecular genetic testing is needed to confirm the diagnosis of LS. A small skin sample called a fibroblast is taken and sent to a biomedical genetics laboratory for testing. Blood testing to determine the DNA mutation of the gene is another method used to diagnose LS.

ICD-9: 270.8

ONSET AND PROGRESSION

People with LS have delayed development and intellectual ability ranges from normal to severely impaired. Renal dysfunction, hypotonia, increased susceptibility to infectious disease; respiratory illness, seizures, and sudden death (usually while sleeping) are the most frequent causes of death during the first years of life in children with LS.

TREATMENT

Currently there is no cure for LS. Treatment includes cataract extraction, glaucoma control, and correction of renal disease. Physical, occupational, and vision therapies, and orientation and mobility services to improve adaptive functioning. School age children require individualized and flexible instructional curricula.

Suggested MER for Evaluation:

• Clinical examination that describes diagnostic features of the impairment and laboratory studies are needed to confirm the diagnosis.

• Developmental assessment or psychological testing to address allegations of mental impairment may be warranted.

Suggested Listings for Evaluation:

DETERMINATION

 LISTING 

REMARKS

Meets Listing

110.08B

LS involves multiple body systems. A description of clinical and laboratory findings will be needed to adjudicate these cases

Medical Equals