Should clinicians recommend carrier screening to all couples planning for a family?
Rare genetic diseases affect more than 300 million people worldwide 1 . According to Genetic and Rare Diseases Information Centre (GARD), more than 7000 known rare diseases are recorded to date 2 . The sheer number of rare disorders means that, collectively, approximately 1 in 17 individuals are affected by them globally. So far, 450 rare disorders have been documented in India, and at least 80% of rare diseases have an identified genetic origin and disproportionately impact children 3 . Hence, with a population of around 1.37 billion and an annual fertility rate of 2.2 children per women, there is a high prevalence of genetic disorders in India.
As per the report from ministry of health, the incidence of genetic origin rare diseases is higher in India due to the practice of consanguineous marriages in many communities, which is directly linked to 56 million people suffering from single-gene disorders. Few studies reported the birth defect prevalence in India as 64.4 (per 1000 live births) 4 , and that 1 out of 20 children admitted to hospital has a genetic disorder that ultimately accounts for about 1 out of 10 childhood deaths 5 . In addition, a WHO report revealed congenital malformations and genetic disorders are the third most common cause of mortality in newborns in urban areas of India 6 . In spite of the high incidence of genetic disorders, the preventive steps in India are only in their infancy. The country also continues to struggle to provide adequate maternal care with only about a quarter of women in the country receive full antenatal care, and 90% receiving some kind of care.
Alternatively, there is no approved treatment for about 95% of rare genetic diseases and less than 1 in 10 patients receive disease-specific treatment. In cases, where treatment is available, it is estimated that the annual cost of treatment for some rare genetic diseases in India may vary from Rs. 20 lakhs to 1.7 crores for a child weighing 10kg. On the other hand, prevention with the help of several diagnostic tests costs around Rs. 10 – 40000 which is extremely cost-effective and simple. Thus, it is important that carrier screening and counselling ideally should be performed before pregnancy because it enables couples to learn about their reproductive risk and consider the most complete range of reproductive options.
Genetic counselling for optimizing outcomes
There is evidence that prevention programs such as genetic counselling and testing before planning baby or at least during the first trimester of pregnancy have been effective in reducing the number of morbidity and mortality rates due to genetic disorders. However, genetic testing’s appropriate usage and understanding the limitations and challenges of available testing approaches are crucial to the successful use of genetics in improving health and quality of life. Therefore, it is crucial that individuals receive timely genetic information about their pregnancy in an understandable fashion that is accurate, and reliable of clinical use.
Genetic counselling helps to identify families at possible risk of a genetic disorder, gather and analyze family history and inheritance patterns, provide information about genetic testing, and guide the couples with the opportunity to consider the most reproductive options. Genetic counsellors answer medical questions, provide education, resources, interpret and explain complex, incidental or uncertain genomic nformation and help people adapt and prepare for any risks or conditions. In addition, genetic counsellors are trained in psychological counselling, as well as genetics, so they can also help couples deal with the emotional side of how genetic conditions can affect a family and provide them with management options.
Integrating test results in clinical practice
Advances in genomic medicine and technological platforms have made possible for low cost, pan‐ethnic expanded genetic testing panels capable of assessing hundreds of mutations that enable obstetric care providers to offer screening for several recessive genetic diseases. It is estimated that the genetic basis of more than 1600 diseases have been identified so far while even more are being investigated. Expanded carrier screening through NGS involving molecular analyses is reported to yield high sensitivity and is considered as the strong predictor of genetic disease occurrence. Hence, given the high burden of the disease and carrier rate in India, population screening to identify mutation carriers with subsequent counselling for at-risk families is highly essential to decrease the disease burden.
As expanded carrier screening technology generate complex genetic data, genetic counsellors play a key role in enabling non-genetic health professionals to learn, understand and integrate genomic data into their practice. They contribute genetic knowledge together with an expert understanding of how to communicate genetic information effectively.
At truGeny, our certified genetic counsellors will help translate genetic information into clinical practice while navigating the psychological, ethical and legal pitfalls. To ensure access to quality genetic services for all individuals, truGeny offers genetic counselling services via tele-genetic sessions with a vision to improve patient’s access to health care in areas with geographical barriers, reducing the cost burden and saving time.
- Wakap, S. N., Lambert, D. M., Olry, A., Rodwell, C., Gueydan, C., Lanneau, V., … & Rath, A. (2019). Estimating cumulative point prevalence of rare diseases: analysis of the Orphanet database. European Journal of Human Genetics, 1-9.
- GARD. FAQs About rare diseases: National center for advancing translational sciences. 2017
- Ministry of health and family welfare
- Christianson, A., Howson, C. P., & Modell, B. (2005). March of Dimes: global report on birth defects, the hidden toll of dying and disabled children. March of Dimes: global report on birth defects, the hidden toll of dying and disabled children.
- VBabu, R., & Ghosh, K. (2005). Chromosomal variants and genetic diseases. Indian Journal of Human Genetics, 11(2), 59-60.
- World Health Organization. (2004). Identifying Regional Priorities in the Area of Human Genetics in SEAR: report of an intercountry consultation, Bangkok, Thailand, 23-25 September 2003 (No. SEA-RES-121). WHO Regional Office for South-East Asia.