Mitochondrial Fission Factor Gene Mutation: A Dilemma for Prenatal Diagnosis

Mitochondrial fission factor (MFF) gene mutations are rare mitochondrial fission disorders, resulting in autosomal recessive neurological disorders. We here report a rare case of MFF gene mutation running in a family which ultimately turned out to be a variant of unknown significance. A 29-year-old multigravida visited at 18-week gestation for prenatal genetic testing as her previous baby had cerebral palsy and global developmental delay. The exome sequencing of the affected baby revealed defective mitochondrial and peroxisomal fission 2 (AR-617086). On Sanger sequencing, the mother was homozygous and the father heterozygous for the same variant. In the current pregnancy, amniocentesis was done and the fetus was also homozygous for a similar mutation. The couple continued the pregnancy and delivered a healthy baby who had normal milestones at 11 months of age. As far as prenatal diagnostic testing is considered, our case is a real-world scenario, where patient expectations befuddle appropriate decision-making.