# Genetic Anomalies in Pediatric Orthopedics: A Case Study of a New Rare Sporadic Mutation of Osteogenesis Imperfecta

## TL;DR

A rare new mutation in the COL1A2 gene was found in a young boy with severe bone disease, leading to early treatment.

## Contribution

Identification of a novel, rare COL1A2 mutation in a sporadic case of OI type III.

## Key findings

- Exome sequencing confirmed a new COL1A2 gene variant in a three-year-old with OI type III.
- Prenatal ultrasound detected skeletal abnormalities, confirmed at birth and later genetically.
- Pamidronate treatment was initiated at seven months to manage the condition.

## Abstract

Osteogenesis imperfecta (OI) arises from a collagen type 1 defect due to several gene mutations, particularly COL1A1 and COL1A2. Its inheritance pattern is typically autosomal dominant, which is more common, or autosomal recessive, although sporadic cases also occur. Prenatal ultrasound can detect severe types, but genetic testing is necessary for confirmation, often at birth or in early childhood. We present a rare case of sporadic OI type III involving a three-year-old boy. Prenatal ultrasound initially revealed limb deformities and skeletal dysplasia, with subsequent confirmation at birth through bone deformities and multiple fractures. Exome sequencing confirmed the diagnosis at 15 months, revealing a new, rare variant in the COL1A2 gene. Pamidronate treatment began at seven months.