Legg-Calvé-Perthes Disease, ..., (Legg-Calvé-Perthes disease) - Gen COL2A1.  

The Legg-Calve-Perthes disease is a bone alteration affects hips. Usually only one hip is involved, but in about 10% of cases both hips are affected. Legg-Calvé-Perthes begins in childhood, usually between 4 and 8 years of age and affects more often children than girls.

In this disease, the femoral head is broken. As a result, the femoral head is not round and does not move easily in the hip socket, causing hip pain, lameness, and limited movement of the leg. Over time, the bone begins to heal by bone remodeling. This cycle of rupture and healing can be repeated several times. Many people with Legg-Calvé-Perthes go on to develop painful osteoarthritis in the hips at an early age.

This disease is due to mutations in the COL2A1 gene, located on the long arm of chromosome 12 (12q13.11). This gene encodes a component of collagen type II, called the pro-alpha1 (II) chain. This type of collagen is found primarily in the vitreous and cartilage. Most cartilage is later converted to bone. Collagen type II is essential for normal bone development and other connective tissues that form the support frame body. Collagen type II is also part of the vitreous, the inner ear, and the nucleus pulposus.

Mutations in the COL2A1 gene can cause bone abnormalities characteristics Calve Legg-Perthes. These mutations change the individual amino acids in pro-alpha1 (II) collagen type II chain. While still altered protein is incorporated into collagen fibers, the fibers may be less stable than normal. It is believed that the breakdown of bone characteristic of Legg-Calve disease-Perthes is due to impaired blood flow in the femoral head, causing osteonecrosis. However, it is unclear how the alteration of collagen II is involved in this process or why the hips are particularly affected.

When the disease is due to mutations in the COL2A1 gene is inherited in an autosomal dominant pattern, which means that a copy of the COL2A1 gene altered in each cell is sufficient for the disease to be expressed. However, most cases of illness associated with the COL2A1 gene are due to new mutations in the gene and occur in people with no history of disease in your family. These are known as sporadic cases.

Tests in IVAMI: in IVAMI perform detection of mutations associated with Legg-Calve disease-Perthes, by complete PCR amplification of exons COL2A1 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).