Genetic analysis and prenatal diagnosis of a Chinese pedigree affected with microphthalmia/coloboma and skeletal dysplasia syndrome due to variant of MAB21L2 gene

Objective: To explore the genetic basis for a Chinese pedigree affected with microphthalmia.

Methods: Clinical data of the proband was collected. Whole exome sequencing (WES) was carried out to screen potential pathogenic variants in the proband. Candidate variant was verified by Sanger sequencing of the proband and his family members. Pathogenicity of the variant was predicted by searching the PubMed database and bioinformatic analysis. Sanger sequencing of amniotic fluid sample was carried out for prenatal diagnosis.

Results: The proband and his father were found to harbor a heterozygous c.151C>G (p.R51G) variant of the MAB21L2 gene. The same variant was not found in his mother and grandparents. Based on the guidelines of American College of Medical Genetics, the c.151C>G (p.R51G) variant was predicted as likely pathogenic.

Conclusions: The c.151C>G (p.R51G) variant of the MAB21L2 gene probably underlay the microphthalmia in the proband. Above finding has facilitated prenatal diagnosis for this pedigree.