In the United States, newborn screening has expanded well beyond a small initial panel and now includes a broad range of inherited and metabolic disorders.
Newborn screening in the United States is carried out using a heel-prick blood test, often referred to as the newborn blood spot screening test, within the first few days of life. While the exact panel varies by state, all states screen for a core group of serious conditions, and many screen for additional inherited disorders.[1]
Depending on the state, newborn screening may include metabolic, endocrine, and genetic conditions such as:
• Phenylketonuria (PKU)
• Congenital hypothyroidism
• Sickle cell disease (SCD)
• Cystic fibrosis (CF)
• Medium-chain acyl-CoA dehydrogenase deficiency (MCADD)
• Maple syrup urine disease (MSUD)
• Homocystinuria
• Glutaric acidemia type 1 (GA1)
• Isovaleric acidemia (IVA)[2]
This broader approach allows many serious conditions to be identified early, often before symptoms appear, so treatment can begin as quickly as possible.
This week we will be learning more about Maple Syrup Urine Disease (MSUD) and Isovaleric Acidaemia (IVA). Both MSUD and IVA are genetic conditions. This means if both parents are a carrier of the gene each baby they have together will have a 25% chance of being born with the condition, 50% chance of being a carrier for the condition, and a 25% chance of being unaffected – thankfully both of these conditions are incredibly rare.
MSUD and IVA are also both metabolic conditions. A metabolic disease is a condition where the body is unable to break down the food we eat to turn it into fuel. Enzymes are responsible for breaking down specific substances; in metabolic conditions this process is not effective of breaking down certain substances. This can result in a build-up of toxins which can be incredibly harmful to the body as the body has no way to eliminate these toxins.
Over the course of the week we will be looking at Maple Syrup Urine Disease and Isovaleric Acidaemia in more detail in order to raise awareness of both of these rare conditions.
[1] https://newbornscreening.hrsa.gov/newborn-screening-process [2] https://newbornscreening.hrsa.gov/conditions
