Prenatal diagnosis of rare genetic disorders: fourteen years' experience of a tertiary genetic centre from India.

Background: Rare genetic disorders are increasingly diagnosed due to advancing genetic technology, whilst, treatment for them is challenging. Therefore, their prevention by prenatal diagnosis is a way forward to reduce the overall burden. The present study provides an overview of a cohort of patients who were offered prenatal diagnosis for genetic disorders at a tertiary genetic center in India.

Methods: The study included 1,738 prenatal samples for the period of 2008 to 2022, identified as being at high risk for rare genetic disorders based on family history, previous affected children, and abnormal ultrasound findings. Participants underwent prenatal diagnostic tests, including chorionic villus sampling or amniocentesis, or fetal blood by various molecular techniques and enzyme-based studies. Data regarding patient demographics, types of disorders screened, and diagnostic outcomes were collected and analyzed.

Results: Of the 1738 cases, 467 (26.87%) prenatal samples were identified as being affected by genetic anomalies. The diagnosed conditions included hematological disorders (n = 735/1738, 42.28%), inborn errors in metabolism (n = 513/1738, 29.52%), neurological disorders (n = 310/1738, 17.84%), musculoskeletal disorders (n = 45/1738, 2.59%), and other rare genetic disorders (n = 135/1738, 7.77%). Early diagnosis facilitated timely medical information and provided options for prevention, such as medical termination of pregnancy (MTP) in affected cases after genetic counseling.

Conclusion: Our study demonstrates that prenatal diagnosis for rare genetic disorders is an invaluable step toward reducing the burden of these conditions. The use of advanced genetic techniques, combined with genetic counseling, enables effective prevention strategies. However, challenges such as accessibility, cost, and ethical considerations continue to pose barriers to widespread implementation in India. Increased awareness and government policy support are essential to make these diagnostic services universally available and affordable.