Academic literature on the topic 'Osteogenesis imperfecta Genetic aspects; Genetic disorders; Genetic counselling'

Osteogenesis imperfecta (imperfect osteogenesis in the Russian literature) is the most common hereditary form of bone fragility, it is a genetically and clinically heterogeneous disease with a wide range of clinical severity, often leading to disability from early childhood. It is based on genetic disorders leading to a violation of the structure of bone tissue, which leads to frequent fractures, impaired growth and posture, with the development of characteristic disabling bone deformities and associated problems, including respiratory, neurological, cardiac, renal impairment, hearing loss. Osteogenesis imperfecta occurs in both men and women, the disease is inherited in both autosomal dominant and autosomal recessive types, there are sporadic cases of the disease due to de novomutations, as well as X-linked forms. The term “osteogenesis imperfecta” was coined by W. Vrolick in the 1840s. The first classification of the disease was made in 1979 and has been repeatedly reviewed due to the identification of the molecular cause of the disease and the discovery of new mechanisms for the development of osteogenesis imperfecta. In the early 1980s, mutations in two genes of collagen type I (COL1A1and COL1A2) were first associated with an autosomal dominant inheritance type of osteogenesis imperfecta. Since then, 18 more genes have been identified whose products are involved in the formation and mineralization of bone tissue. The degree of genetic heterogeneity of the disease has not yet been determined, researchers continue to identify new genes involved in its pathogenesis, the number of which has reached 20. In the last decade, it has become known that autosomal recessive, autosomal dominant and X-linked mutations in a wide range of genes, encoding proteins that are involved in the synthesis of type I collagen, its processing, secretion and post-translational modification, as well as in proteins that regulate the differentiation and activity of bone-forming cells, cause imperfect osteogenesis. A large number of causative genes complicated the classical classification of the disease and, due to new advances in the molecular basis of the disease, the classification of the disease is constantly being improved. In this review, we systematized and summarized information on the results of studies in the field of clinical and genetic aspects of osteogenesis imperfecta and reflected the current state of the classification criteria for diagnosing the disease.

A rare disease afflicts less than 200,000 individuals, according to the National Organization for Rare Diseases (NORD) of the United States. Over 6,000 rare disorders affect approximately 1 in 10 Americans. Rare genetic bone disorders remain the major causes of disability in US patients. These rare bone disorders also represent a therapeutic challenge for clinicians, due to lack of understanding of underlying mechanisms. This systematic review explored current literature on therapeutic directions for the following rare genetic bone disorders: fibrous dysplasia, Gorham-Stout syndrome, fibrodysplasia ossificans progressiva, melorheostosis, multiple hereditary exostosis, osteogenesis imperfecta, craniometaphyseal dysplasia, achondroplasia, and hypophosphatasia. The disease mechanisms of Gorham-Stout disease, melorheostosis, and multiple hereditary exostosis are not fully elucidated. Inhibitors of the ACVR1/ALK2 pathway may serve as possible therapeutic intervention for FOP. The use of bisphosphonates and IL-6 inhibitors has been explored to be useful in the treatment of fibrous dysplasia, but more research is warranted. Cell therapy, bisphosphonate polytherapy, and human growth hormone may avert the pathology in osteogenesis imperfecta, but further studies are needed. There are still no current effective treatments for these bone disorders; however, significant promising advances in therapeutic modalities were developed that will limit patient suffering and treat their skeletal disabilities.

The article presents the modern views of clinicians and geneticists on one of the most severe genetic disorders of skeletal and connective tissues - osteogenesis imperfecta. The review provided the literature data that showed the incidence rates, genetic heterogeneity of osteogenesis imperfecta, as well as the role of some proteins involved in the construction of bone tissue, as well as a clinical classification of the main types of the disorder. The authors described a clinical case: a girl with typical clinical and radiological manifestations of the rarest of all types of osteogenesis imperfecta - type II (perinatal-lethal, congenital osteogenesis imperfecta, Vrolik’s syndrome). The child’s diagnosis was verified by a parallel DNA sequence analysis which showed a heterozygous mutation in exon 29 (c.1966G> A) of COL1A1 gene not previously described in the literature. It caused the substitution of glycine for serine at position 656. The role of antenatal diagnostics and the importance of medical genetic counselling of the family before planning the next pregnancy due to the existing risk of re-birth of a sick child is outlined. Due to the fact that majority of the patients with the most prognostically unfavourable type II osteogenesis imperfecta, as a rule, die in utero, the described case of observation of the girl with typical clinical and X-ray signs of the disorder for almost 3 months of postpartum period is extremely rare and highly indicative. The detection of the heterozygous mutation in exon 29 (c.1966G > A) of COL1A1 gene by a parallel DNA sequence analysis which was not previously described in the literature gives an additional significance to the described observation.

AbstractTaurodontism is a dental anomaly defined by enlargement of the pulp chamber of multirooted teeth with apical displacement of the pulp floor and bifurcation of the roots. Taurodontism can be an isolated trait or part of a syndrome. A study was conducted to document the dental and craniofacial aspects of genetic thin bone disorders in South Africa. Sixty-four individuals with Osteogenesis imperfecta (OI), one individual with Pyle disease and one with Torg-Winchester syndrome respectively, were assessed clinically, radiographically and at a molecular level. Ten patients with OI XI and those with Pyle disease and Torg-Winchester syndrome had taurodontism. Taurodontism has been identified in several genetic disorders necessitating cognizance of the possible existence and implications of this characteristic when managing patients in the dental environment. Further studies should be directed toward identifying the incidence, etiology, and molecular pathways leading to taurodontism and its relationship to genetic syndromes.

Bibliography: leaves 457-506.
2 v. (506 leaves) :
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Addresses the problem of giving genetic counselling to parents of a "sporadic" case of severe osteogenesis imperfecta, either of the perinatally lethal or severe deforming variety.
Thesis (M.D.)--University of Adelaide, Dept. of Paediatrics, 1994

Bibliography: leaves 457-506.
2 v. (506 leaves)
Addresses the problem of giving genetic counselling to parents of a "sporadic" case of severe osteogenesis imperfecta, either of the perinatally lethal or severe deforming variety.
Thesis (M.D.) -- University of Adelaide, Dept. of Paediatrics, 1991