Hereditary diseases of the skeleton

The human skeleton is a highly organized connective tissue susceptible to severe hereditary diseases. These are genetically caused disorders in which bone and cartilage are affected. Hereditary diseases of the skeleton make up more than half of all congenital diseases and malformations in children. Most of the diseases of the musculoskeletal system are hereditary to some extent.

Hereditary diseases of the skeleton can be divided into chromosomal and gene. Most chromosomal diseases are accompanied by multiple severe malformations of the skeleton( Down syndrome, Edwards syndrome, Shereshevsky-Turner, Klinefelter, Patau).Genetic diseases of the skeleton can manifest from the moment of birth( achondroplasia, diastrophic dysplasia, congenital clubfoot) or somewhat later, when the child is born without visible bone anomalies, and the disease develops gradually, and the first manifestations can be seen in subsequent years of life. In addition, there are a number of diseases that occur even from the moment of birth, but the appearance of the child differs sharply from the pattern characteristic for the disease, developing at a later age( metatropic dysplasia, congenital spondylo-epiphysial dysplasia).

Among hereditary diseases of the musculoskeletal system, a special place is occupied by hereditary systemic diseases of the skeleton. This severe category of hereditary diseases constitutes an extensive group. Hereditary systemic diseases of the skeleton are related to generalized( common) diseases of connective tissue, so that the pathological process may involve bone, tendons, ligaments, eyes, inner ear and internal organs, ie all organs in which connective tissue is present. However, the leading sign of such diseases is still the defeat of bone and cartilage, which is manifested in a violation of the growth and development of the osteoarticular apparatus of the child. Many forms of hereditary systemic diseases of the skeleton are accompanied by disproportionate dwarfism: either limb shortening or shortening of growth due to the primary lesion of the spine is noted. Part of the hereditary systemic diseases of the skeleton may appear already at birth. In this case, they are forms that lead to the death of a child before or soon after birth. However, some forms still are compatible with life( achondroplasia, diastrophic dysplasia, metatropic dysplasia, Kniz dysplasia, congenital spondylo-epiphyseal dysplasia), although lead to severe deformities. A significant part of hereditary systemic diseases of the skeleton manifests itself only in the subsequent years of life, mainly at 3-6 years of age. All hereditary systemic diseases of the skeleton are characterized by a constantly progressive course, as well as a pronounced variety of manifestations. Hereditary systemic diseases of the skeleton can be transmitted by autosomal dominant, autosomal recessive or X-linked inheritance types. Some forms of hereditary systemic diseases of the skeleton with the same manifestations can be transmitted immediately through several types of inheritance. Currently, more than 150 different forms of hereditary systemic diseases of the skeleton have been described. All of them are rare, but extremely serious diseases. Hereditary systemic diseases of the skeleton represent one of the most complex groups of orthopedic diseases. Despite the relative scarcity, they cause significant damage to the family and society, leading the patients to an early and severe disability. In general, hereditary systemic diseases of the skeleton remain poorly understood. Essential causes of this are the rarity of these diseases and a significant variety of their manifestations.

All hereditary diseases of the skeleton can be divided into three groups, depending on the portion of the bone where the formation of the bone begins. The following parts are distinguished in the bone: epiphysis, metaphysis and diaphysis. Diaphysis is the middle part of the bone;epiphysis - the ends of the bone, covered with articular cartilage;metaphysis - a bone site located between the diaphysis and the epiphysis. Correspondingly to the indicated parts of the bone, dysplasia is divided into epiphyseal, diaphyseal and metaphyseal. The most typical representatives of epiphyseal dysplasia are spondylo-epiphyseal dysplasia and multiple epiphyseal dysplasia.