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Congenital Hypothyroidism and Phenylketonuria

Hi everyone! I hope summer has been well. In today's post, I'm going to be talking about two of the main diseases that can be detected by newborn screenings! Keep reading for more information!

Newborn Screenings

In case you don't remember or you are new to my blog, I'll quickly summarize. A newborn screening examination tests for numerous diseases that must be diagnosed within the first few weeks of birth to avoid life threatening or life altering consequences, such as intellectual disability or even death. Some of those disorders can only be diagnosed through the screening, which demonstrates its importance in potentially saving a baby's life. For more information on what newborn screenings are and what I'm advocating for, you can read my previous blog post here. Remember that the diseases tested for by newborn screenings tend to differ by region based on the prevalence of certain disorders. For the rest of this post, I'll be talking about two of the most common diseases that are diagnosed with newborn screenings: congenital hypothyroidism and phenylketonuria (PKU). They are screened for in all 50 states of the U.S.

Congenital Hypothyroidism

This is a disorder in which the baby is born with too little thyroid hormone. That could be due to a dysfunctioning, undeveloped, or completely missing thyroid gland. There are two active thyroid hormones that should be secreted by the thyroid gland: triiodothyronine (T3) and thyroxine (T4). Those hormones regulate brain growth, body weight, energy levels, internal temperature, body growth, and metabolism. If there is not enough thyroid hormone being secreted, those factors could be affected drastically.

A study by the National Center for Biotechnology Information (NCBI) explains that the disease "must be diagnosed promptly because delay in treatment can lead to irreversible neurological deficits." The late diagnosis of congenital hypothyroidism can lead to mental developmental problems and poor growth. In other words, a baby can become intellectually disabled and have lifelong stunted growth if they are not diagnosed soon after birth. This unfortunately happens too often due to the lack of awareness about newborn screenings in many countries around the world. The importance of newborn screenings are now increasing since cases of congenital hypothyroidism have almost doubled in the past twenty years.

Phenylketonuria (PKU)

PKU is an inherited disease in which the body increases the levels of a protein known as phenylalanine in the blood and is no longer able to metabolize the protein. If PKU is left untreated, phenylalanine levels in the body will build up to harmful levels, which will cause intellectual disability and other serious health issues.

PKU symptoms will not show up in children until they are a few months old, as opposed to symptoms of congenital hypothyroidism, which start to appear within days of birth. Some of the symptoms of PKU are seizures, delayed development, behavioral problems, and psychiatric disorders. Phenylketonuria is typically detected during newborn screenings, and treatment is begun promptly after diagnosis. If it is not diagnosed from newborn screenings, it most likely will not be found until symptoms appear, and by that time, it will be too late to reverse the damage that has already been done. That time period without treatment would have already caused permanent brain damage, and waiting too long, would, as I mentioned earlier, lead to permanent intellectual disability.

Summary and Taking Action

Congenital hypothyroidism and phenylketonuria are two major disorders that are tested for during newborn screenings, and they are screened in almost every location due to their prevalence and importance. Both disorders can lead to intellectual disability if not diagnosed or treated on time.

So what am I doing about this, and what can you do to help? The first step is to raise awareness. While the newborn screening program is well known around the U.S, a very small portion of the global population is aware of its benefits and importance. You can help by telling people about newborn screenings and sharing my blog to get the word out. I also plan to start a fundraiser sometime soon, so I'll give out updates on that.

That's all for this month! If you're interested in learning more or would like to check out where I got my information, here are my works cited and references for this post.

As always, don't forget to share to friends and family, and please subscribe if you haven't already. Thank you for reading, and I'll see you next month.

Signing off,



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