Next Generation Sequencing (NGS)

According to statistics, about 7 in 100 people have a chance of genetic disorders that can be passed on to their children. Some people suffer from the disorders or are carriers of the disorders, so their babies are born unhealthy and cannot be cured, which may be costly. The common inherited disorders in Thailand include thalassemia, Duchenne muscular dystrophies, spinal muscular atrophy, and haemophilia, etc.

As a result of cooperation between the public and private sectors including a research team from the Medical Genome Center at Ramathibodi Hospital under the support by the Thailand Centre of Excellence for Life Sciences (TCELS), Leader Medical Genetics and Genomics company (LMGG), the Thai Reproductive Genetic Company (TRG), N-Health and Samitivej Hospital, we are able to identify 600 genetic disorders which can be passed from a father or mother to their child for the first time in Thailand. The Next Generation Sequencing or NGS is an advanced technology used to decode the genes before a family makes the decision to conceive. With the latest technology and a team of dedicated NGS experts, carrier testing can be conducted to check for hereditary conditions which may cause disability and organ damage in a baby. This technology can be used to test for approximately 600 genetic disorders which can be passed from a father or mother to their child. Below is a list of 12 commonly inherited disorders:

• Thalassemia
• Phenylketonuria
• Duchenne and Becker muscular dystrophies
• Galactosemia
• Spinal muscular atrophy
• Glycogen storage disease type II, or Pompe’s disease
• Haemophilia
• Wilson’s disease
• Fragile X syndrome
• Polycystic kidney disease
• Congenital hearing loss
• Congenital adrenal hyperplasia

This technology can be used for 2 cases. Firstly, this technique is used for couples wanting to have a child but who are over the age of 35, have genetic disorders, are carriers of disorders, have a family history of genetic disorders, or had their first child with genetic disorders and now plan to have their second one. Secondly, this technique is used for couples who are experiencing infertility problems. In these cases, genetic disease free embryos can be selected for implantation, so as to ensure that the baby is healthy.

The technique involves doctors examining DNA extracted from the blood or cheek cells of the couple, their relatives, the embryo and the amniotic fluid so as to check for abnormalities. The testing takes about 3-6 months to complete and can be performed at 3 phases:

1. Pre-conception carrier screening for 12 common genetic disorders in Asian people and up to 600 genetic disorders in total.
2. Pre-implantation genetic diagnosis to examine IVF embryos for genetic abnormalities and avoid genetic abnormalities inherited from parents who suffer from the disorders or are carriers of the disorders.
3. Pregnancy screening to check for chromosomal abnormalities causing intellectual and physical disabilities through testing of the mother’s blood or amniotic fluid analysis.

In the past, newborns could only be screened for thalassemia and no other conditions causing disabilities could be detected. Otherwise, when a first child was born with disorders, the parents would be examined to determine whether they were carriers of the disorders, resulting in reluctance for these couples to have a 2^nd child. However, if parents know that they are carriers of certain disorders or are at risk of having children with genetic disorders, they can avoid passing on genetic abnormalities through IVF technology and pre-implantation genetic diagnosis.

This research is 95% accurate in solving genetic abnormalities passed on from a father or mother to their child. It is another medical achievement that will bring happiness and health in the family by preventing genetic disorders in children. The genetic code can be compared to a book of life that can tell our future.