Abstract:

Objective: To investigate the carrier status of monogenic genetic diseases in couples of childbearing age in Gansu, and to carry out genetic counseling and prenatal diagnosis for high-risk families. Methods: A total of 887 couples of childbearing age who were recruited in Gansu Province Maternity and Child Care Hospital from January 2021 to December 2023 were included. Expanded carrier screening (ESC) for 100 single-gene recessive genetic diseases were detected by the target region capture-NGS detection technology. When the mothers of the three families were pregnant, 15 mL of amniotic fluid was drawn at 18-21 weeks of pregnancy for prenatal genetic diagnosis. Results: Among 887 couples of childbearing age, 31 high-risk couples were detected, of which 25 couples were at high risk of autosomal recessive genetic disease and 6 couples were at high risk of X-linked recessive genetic disease. Of the 1 774 persons (887 couples), 678 cases were carriers of autosomal recessive genetic diseases. The prevalence of GJB2 gene was the highest in high-risk couples, followed by PAH gene and CFTR gene. Among the 31 positive couples, 3 couples underwent prenatal diagnosis during pregnancy. One case was a fetus with cystic fibrosis, and the couple′s family chose to terminate the pregnancy. One case was a carrier and one case wild type, their neonatal phenotypes were normal. Conclusions: ECS for couples of childbearing age is helpful to implement the accurate prenatal diagnosis and fertility guidance, which is of great significance in reducing birth defects.

Key words: Expanded carrier screening, Monogenic genetic diseases, Genetic counseling, Prenatal diagnosis, High-throughput nucleotide sequencing