[Phenotype-genotype analysis and detection of gene variant in six families with osteogenesis imperfecta]

To analyze the clinical phenotype of six pedigrees affected with osteogenesis imperfecta and their genetic basis.

Peripheral blood or abortic tissues of the six pedigrees were collected for the extraction of genomic DNA. Next generation sequencing (NGS) was carried out to detect pathological variants in the genome. Sanger sequencing was used for validating suspected variant among the six pedigrees and 100 healthy controls.

In pedigree 1, the proband and his daughter both carried a heterozygous c.1976G>C variant of COL1A1. The probands in pedigrees 2 to 6 respectively carried heterozygous variants of c.2224G>A of COL1A2, c.2533G>A of COL1A1, c.2845G>A of COL1A2, c.2532_2540del of COL1A1, and c.1847G>A of COL1A2. The same variants were not detected in their parents and the 100 healthy controls.

Variants of COL1A1/2 gene probably underlie the pathogenesis for osteogenesis imperfecta in these pedigrees. Discovery of the nevol variants has enriched the spectrum of COL1A1/2 gene variants and facilitated genetic counseling and prenatal diagnosis for the affected pedigrees.