Неонатологія, хірургія та перинатальна медицина (May 2022)
A CLINICAL CASE OF OSTEOGENESIS IMPERFECT TYPE III, DETERMINED BY COL1A1 (P.GLY845ARG) GENE MUTATION IN A NEWBORN GIRL
Abstract
Osteogenesis imperfecta (OI) is a disease that is characterized by hereditary connective tissue dysplasia and is clinically manifested as excessive bone fragility and limb deformity. The overall incidence of OI is 1:10,000-20,000 live births. The main autosomal dominant inheritance path, autosomal recessive and X-linked forms have been established, and sporadic cases of the disease, denovo mutations and familial mosaicism have been described. 85% of cases are connected with mutations in the COL1A1 and COL1A2 genes, which leads to quantitative and qualitative changes in the synthesis of type I collagen. Quantitative defects are due to the formation of a null allele, in which the structure of collagen remains unchanging, and its amount is halved. Out of qualitative defects, the most common type of mutation is associated with the replacement of glycine with a larger amino acid. This leads to a disruption in the formation of the triple chain and structural changes in the type I procollagen molecule. The article presents a clinical case of type III osteogenesis imperfecta caused by a mutation in the COL1a1 (p.Gly845Arg) gene in a newborn girl. Antenatally diagnosed with oligohydramnios and shortening of the limbs, after birth phenotypically revealed congenital dwarfism with short limbs, small size of the cartilaginous skull, hypertelorism, depressed nose bridge and micrognathia. X-ray examination revealed fractures of the humerus. The results of the molecular genetic study revealed the c.2533G>A (p.Gly845Arg) mutation of the COL1A1 gene. Molecular genetic examination of family members (mother, father and two sisters of the proband) did not reveal the pathological allele diagnosed in the proband, that is, the birth of a child with a hereditary pathology of the musculoskeletal system occurred as a result of a new mutation.
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