Spinal Muscular Atrophy in Children & the role of IVF and Preimplantation Genetic Diagnosis (PGD)

What is Spinal Muscular Atrophy

Spinal Muscular Atrophy (SMA) is a severe genetic disorder affecting children, characterized by progressive muscle weakness and atrophy. It affects the motor neurons in the spinal cord, leading to muscle weakness and atrophy and occurs due to mutations in the SMN1 gene, responsible for producing a protein essential for motor neuron function. As motor neurons deteriorate, muscles weaken, impairing movement, swallowing, and breathing. SMA can manifest in different forms, with the most severe affecting infants and young children, often leading to early death due to respiratory failure. It is classified into types based on severity, with Type 1 being the most severe, often leading to death before two years of age, while milder forms can allow for longer life. Early diagnosis and treatment is key and can help manage symptoms and improve quality of life. Advances in reproductive technologies like In Vitro Fertilization (IVF) combined with Preimplantation Genetic Diagnosis (PGD) offer hope to families at risk of having a child with this disorder.

IVF and PGD: A Breakthrough in Preventing SMA

To understand how these can help treat SMA it is important to know what exactly they are. In vitro fertilization (IVF) is a technique where an egg and sperm are combined outside the body, creating embryos that can be tested for genetic conditions before implantation. Preimplantation Genetic Diagnosis (PGD), on the other hand, is a specialised procedure used alongside IVF to screen embryos for specific genetic disorders, such as SMA, before they are transferred to the mother's uterus. This allows parents to choose embryos that are free of genetic mutations, thereby preventing the transmission of SMA to the child.

IVF and PGD for SMA: A structured process

A stringent process is followed in case of IVF and PGD for SMA. First is IVF which begins with ovarian stimulation. In this the mother undergoes hormone therapy to produce multiple eggs which are then retrieved and fertilised with sperm in the laboratory. Once fertilisation occurs, the embryos are cultured for a few days until they reach a stage where they can be biopsied for genetic testing.

Next PGD starts. PGD is performed by analysing a single cell from each embryo, searching specifically for the genetic mutation that causes SMA. A child will be infected with SMA only if genes from both parents carry the defective SM1 gene. In that case it is typically not chosen for implantation. Only embryos without the SMA mutation are selected and transferred to the mother’s uterus for potential pregnancy.

So, what are the benefits of this? To put it in brief, this process is very effective as it can significantly reduce the risk of having a child with SMA, especially in families where one or both parents are carriers of the gene mutation. In fact carrier testing is often recommended for couples who have a family history of SMA or those in which one or both partners are known to be carriers of the gene.

IVF and PGD is a godsend for afflicted couples who can avoid the emotional and financial costs of raising a child with SMA, as well as the devastating impact of the disease on the child’s health and quality of life.

Ethical and Emotional Considerations

However, in addition to the substantial medical benefits offered by IVF and PGD it is equally true that they also raise some moral and ethical questions. For instance, some parents may have to make difficult decisions regarding embryo selection, especially when embryos carry other genetic traits or conditions. There are also concerns about the potential for genetic screening to be used for non-medical purposes, such as selecting for specific traits. However, for families at risk of SMA, PGD is definitely advisable as it provides an opportunity to ensure that their child will not inherit the condition.

Making a difference

There is no doubt that IVF combined with PGD has revolutionised the way families can prevent genetic diseases like Spinal Muscular Atrophy. It is a medical breakthrough that significantly affects lives. By allowing parents to screen embryos for genetic disorders before pregnancy, these technologies offer a way to reduce the burden of inheriting SMA and ensure healthier outcomes for children. Although the process can be emotionally challenging, it is also a beacon of hope for a future free from the devastating effects of SMA.