Juvenile primary osteoporosis (Juvenile primary osteoporosis) - Gen LRP5.

Juvenile primary Osteoporosis is a skeletal disorder characterized by osteoporosis that begins in childhood. Osteoporosis is caused by a decrease in bone mineral density, making bones fragile and prone to breakage. Often, those affected have multiple fractures in the long bones of the arms and legs, especially in the metaphysis. Multiple fractures can cause bone pain and lead to movement problems.

Juvenile primary osteoporosis is due to mutations in LRP5 gene, located on the long arm of chromosome 11 (11q13.4). This gene encodes a protein located in the outer membrane of many cell types, known as a co-receptor, since it works with another protein frizzled receptor - 4 (produced from FZD4 gene), to transmit chemical signals outside cell to cell nucleus. Frizzled protein - 4 and the LRP5 protein involved in the Wnt signaling pathway, important for the proliferation, adhesion, migration and many other cellular activities. The LRP5 protein, plays an important role in the development and maintenance of various tissues, in the establishment of blood supply to the retina , and inner ear and in the regulation of bone mineral density.

They have identified at least 5 mutations in the LRP5 gene in people with juvenile primary osteoporosis. Mutations in the gene give rise to a protein that can not transmit signals along the pathway. The resulting reduction in signaling affects proper bone development, causing a decrease in bone mineral density and osteoporosis at an early age. Many people will not have a mutation in the LRP5 gene. It is likely that mutations in other genes that have not been identified are involved in this disease.

Juvenile primary osteoporosis is inherited in an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient to cause the alteration. In most cases, an affected person has a parent with the disease.

Tests in IVAMI: in IVAMI perform detection of mutations associated with juvenile primary osteoporosis, by complete PCR amplification of the exons of the LRP5 gene, and subsequent sequencing.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).