PRENATAL SUSPICION OF SKELETAL DYSPLASIA WITH POSTNATAL MOLECULAR CONFIRMATION OF OSTEOGENESIS IMPERFECTA ASSOCIATED WITH A COL1A2 VARIANT: A CASE REPORT

Resumo

Skeletal dysplasias comprise a heterogeneous group of genetic disorders characterized by abnormalities in bone and cartilage development, with wide clinical variability in terms of severity and prognosis. Advances in obstetric ultrasonography have enabled the prenatal suspicion of these conditions during pregnancy. Among these disorders, osteogenesis imperfecta stands out as a hereditary connective tissue disease frequently associated with mutations in the genes responsible for type I collagen synthesis, particularly COL1A1 and COL1A2. This study reports a case of prenatal suspicion of non-lethal skeletal dysplasia with postnatal molecular confirmation of osteogenesis imperfecta associated with the COL1A2 gene. The patient was a primigravida without significant comorbidities who received regular prenatal care. Obstetric ultrasonographic examinations performed from the second trimester revealed marked shortening of the long bones in a micromelic pattern, bowing of the limbs, suspected intrauterine fractures, and reduced mineralization of the cranial vault. Bilateral clubfoot and fetal growth restriction were also observed, while thoracic proportions remained preserved, suggesting the absence of ultrasonographic criteria for lethality. Delivery was performed by cesarean section due to breech presentation. The newborn required resuscitation at birth and was subsequently admitted to the Neonatal Intensive Care Unit. Physical examination revealed limb shortening and dysmorphic facial features, maintaining the clinical suspicion of skeletal dysplasia. Diagnostic investigation was complemented by a next-generation sequencing panel for skeletal dysplasias, which identified a pathogenic heterozygous variant in the COL1A2 gene, confirming the diagnosis of osteogenesis imperfecta. This case highlights the importance of detailed prenatal ultrasonographic evaluation for the early recognition of skeletal dysplasias and underscores the role of molecular testing in establishing the etiological diagnosis and guiding perinatal care planning.