Abstract
<jats:p>Introduction.Mitochondrial diseases (MDs) are clinically heterogeneous disorders caused by mutations across a wide spectrum of genes encoded by the nuclear or mitochondrial genome, and have complex inheritance patterns, including X-linked or autosomal inheritance for mutations in nDNA genes, and maternal inheritance for mtDNA mutations. Mitochondrial complex I (MCI) is the largest and most complicated component of the respiratory chain. The NDUFV1 gene encodes an essential core subunit of the electron-input (N) module of mitochondrial complex I within the oxidative phosphorylation (OXPHOS) system. Methods.Recruitment of the family took place at the Corporate Fund «University Medical Center»(UMC). Blood from the pregnant woman and her partner was collected into a blood collection tube. Chorionic villus sampling (CVS) was performed according to the standard operating procedure (SOP). DNA was isolated using commercially available kits. Variantverification was performed by Sanger sequencing. Sequencing data analyzed using Data Collection Software. Results.A Kazakhstani family with a history of mitochondrial complex I deficiency (MCID), nuclear type 4, autosomal recessive inheritance pattern (OMIM: 618225) was recruited on the basis of the UMC. The parents were verified by Sanger sequencing and are obligateheterozygous carriers of genetic variants in the NDUFV1 gene at the following points: mother –NM_007103.4: c.289C>T (p.Leu97Phe), father –NM_007103.4: c.357G>C (p.Glu119Asp). Prenatal testing detected both heterozygous mutations in points NM_007103.4: c.262C>T (p.Arg88Cys) and NM_007103.4 c.357G>C (p.Glu119Asp) in the fetus. It was recommended to observe by a pediatrician with no specific treatment. Also, medical and genetic counseling of the couple when planning the next pregnancy was recommended. Conclusion.NDUFV1-related MCID can lead to a broad spectrum of clinical outcomes and complications and may progress rapidly. Therefore, early recognition is essential to ensure timely diagnosis and appropriate management. Our findings highlight the importanceof early prenatal genetic testing for NDUFV1-associated MCID, which can facilitate early detection and support informed decision-making during pregnancy. Key words:mitochondrial diseases,prenatal genetic testing,NDUFV1,mitochondrial complex I deficiency.</jats:p>