We review classification and typical manifestations of the various inborn errors of metabolism. We are joined by Luis Umaña, MD, Assistant Professor of Pediatric Genetics at the University of Texas Southwestern Medical Center.
Dr. Neeta Goli:
Welcome to Newborn News, a podcast where we discuss educational topics for medical professionals who care for newborns. I'm your host, Dr. Neeta Goli, a pediatrician in the UT Southwestern newborn nursery. Welcome back to the podcast. In today's episode, we'll be discussing metabolic disorders which can manifest in the newborn period. We're recording remotely due to the ongoing COVID pandemic. We are joined today by Dr. Luis Umaña, Assistant Professor of Pediatric Genetics and Metabolism at UT Southwestern.
Dr. Luis Umaña:
Hello?
Dr. Neeta Goli:
Hi. Is this Dr. Umaña?
Dr. Luis Umaña:
This is Dr. Umaña.
Dr. Neeta Goli:
Yes. Hi, this is Neeta. Thank you so much for joining us today for this podcast.
Dr. Luis Umaña:
Hello. Thank you for the invitation.
Dr. Neeta Goli:
Okay. So we can go ahead and get started. So when we talk about metabolic disorders, we're really referring to a broad and complex class of disorders which includes defects in the metabolism and storage of carbohydrates, proteins, and lipids. These disorders are not common, occurring in about 1 in 1,500 live births, but if not diagnosed early can lead to significant morbidity and mortality.
Dr. Neeta Goli:
If you've already listened to our newborn metabolic screening episode, you'll remember that phenylketonuria was the first metabolic disorder which spurred the advent of newborn screening in the 1960s. This program has since expanded to include several additional disorders.
Dr. Neeta Goli:
In today's episode, we'll discuss the classification of these metabolic disorders. And in our next episode, Dr. Umaña will join us again to discuss their management. So from my standpoint as a general pediatrician, it can sometimes feel daunting to remember the details of all these disorders and how to tell them apart. So to start off with Dr. Umaña, please can you help us sort through the classifications of the different types of metabolic disorders?
Dr. Luis Umaña:
So I agree with you. The importance of metabolism... Quite a large group of conditions. Most of them are quite infrequent in the population. And many of us, even those who specialize in inborn errors of metabolism, keeping track of them is quite difficult. There have been different ways to try to organize them into groups. Most recently in 2019, a new nosology was proposed and it included over 1,000 well-described inborn errors of metabolism and over 100 that could have a metabolic component, but their description was less clear.
Dr. Luis Umaña:
When I approach a metabolic disorder, there's different questions that I ask myself. The first one is, "Will this be a disorder that is amenable to treatment or not?" Because that really will lead the urgency of your diagnosis. You cannot miss or delay diagnosis of those treatable disorders. If we're going to think it from the clinical standpoint, I think that rather than thinking first on the pathways, it's just grouping them into three groups.
Dr. Luis Umaña:
The first group, what is proposed, is to be called disorders that lead to intoxication. These are disorders in which you accumulate a compound or a chemical substance in your body, which is proximal to a metabolic block. And accumulation of this compound will lead to end organ damage, which could affect the brain, the heart, the kidney, be a multisystemic disorder. In this group is where we would have conditions such as phenylketonuria, homocystinuria, maple syrup urine disease, galactosemia, Wilson disease, porphyrias. In all of those, you are accumulating a toxin and that's what is leading to the symptoms. And then the management is aimed at both getting rid of this offending compound and then limiting the amount or the rate at which your body will either take it or produce it. And this is probably the first group of conditions that people think of when they are asked about importance of metabolism.
Dr. Luis Umaña:
The second group is the disorders of energy metabolism. These are disorders in which for different reasons, there is a lack of energy supplies to the cells. So this will include disorders in which glucose is not made available, especially the case of the glycogen storage diseases, the fatty acid oxidation disorders, or disorders in which there's an impairment in the utilization of glucose. Here is where you would include what is termed as a mitochondrial disorder which really affect how the tricarboxylic acid and the respiratory chain work. So the management of these disorders really is to try to improve that energy utilization or the availability of substrates for energy production.
Dr. Luis Umaña:
And then the third group is what we call the disorders of complex molecules. These are much larger molecules, these accumulated slowly over time, or they become depleted slowly over time. They tend to be more chronic multi-systemic. Very few of them will have an effective treatment just because how widespread the impact of these conditions are. And this is where you're going to see conditions such as the mucopolysaccharidoses and what we call the storage disorders, the peroxisomal disorders such as Zellweger, and another newer group of conditions that we call the disorders of glycosylation which are disorders in which the modification of proteins after they have been synthesized is impaired and then those proteins cannot pursue their options.
Dr. Luis Umaña:
So once we think about these three groups, we need to think, when is it manifesting? Because some disorders will manifest prenatally, some others will manifest in the neonatal period or infancy, and others may appear later in life such as in childhood, adolescence, adulthood, and some disorders might not appear until you are of very advanced age. And so then you have conditions that will have acute manifestations, very common for those disorders of intoxication and energy metabolism, or being chronic or progressive, such as is the case for the complex molecules.
Dr. Luis Umaña:
And there are disorders that we can have both acute and chronic components. One example of this are some organic acidurias in which you can have acute metabolic decompensation with severe acidosis. But in between those acute periods, even when the patient is well-controlled, you can see progressive end organ damage. And many organic aciduria patients might develop cardiomyopathy, or renal insufficiency, or optic nerve atrophy that will happen over time. So that will also help us decide when I'm encountering a patient, where do you fit? Is this an infancy disorder? Or is this a disorder of older ages?
Dr. Luis Umaña:
If I were to think of the most common group of disorders, those that would affect the neonatal period, again, most of those will be disorders of intoxication or energy metabolism. And I would include here the urea cycle disorders, the organic acidemias, the disorders of fatty acid oxidation, the amino acidopathies, and disorders of carbohydrate metabolism. I will also think here of the glycogen storage diseases and the mitochondrial disorders. So most of the big two first groups that we discussed.
Dr. Luis Umaña:
Now when they present, and especially newborns in whom the amount of symptoms that they can exhibit is quite limited. Discerning between one or the other disorder might not be easy and there's significant overlap. Luckily for many of them, the treatments tend to be so similar that you can start treatment until you get all of your confirmatory labs to decide exactly what is the specific condition that you're treating. And so sometimes, the small pearls or clues can give you ideas about what is going on.
Dr. Luis Umaña:
So a good exploration of the newborn, a good exploration of their biochemical patterns even from your routine lab work can give you a lot of information. For example, in the organic acidemias, you could have hyperammonemia and hypoglycemia. But really, it's the degree of that acid-base disturbance which is so significant. While in the urea cycle defect, you still could have hyperammonemia, but this one... It's so much more significant than the acid-base disturbance.
Dr. Luis Umaña:
So you can see on the organic acidemia that patients with pH of 7 or 6.9 and hyperammonemia, so 400 or 600. While in the urea cycle, you will see a patient that has a pH of probably 7.48 or 7.5, more ammonia in the 1000 or 2000 level. So it's a matter of picking up which of the abnormalities is the most preponderant one, what can lead you to a suspicion of why this patient is becoming sick.
Dr. Luis Umaña:
And again, the idea is just to try to identify those disorders that are treatable. We can go and review some of the manifestations of these disorders as it happens often in the different text books. But there are different things to consider and hopefully some of these might be helpful. So let's start with the urea cycle defects.
Dr. Luis Umaña:
These disorders, all of them are due to impairment in the detoxification of excess nitrogen which has been released by amino acids and it is released in the form of ammonia. What happens is that the urea cycle will conjugate this ammonia all the way into the urea. And urea will be excreted then by the kidney. It will also lead to the synthesis of both citrulline and arginine. Arginine really is quite important because for patients with urea cycle defect, it becomes an essential amino acid and will become an important part of the treatment.
Dr. Luis Umaña:
This ammonia that does not get excreted as urea, will lead to rapid neurological deterioration. So these are newborns that on day two or three of life, will present with progressive lethargy, poor feeding, some vomiting, and if we were to go into their system, it's this ammonia permeating into the brain causing accumulation of glutamate. Sometimes you will see some excitotoxicity and you will see hyperreflexia and clonus in many of these babies. And the other thing that will happen is at the level of the CSF, the ammonia will dissociate and it will release hydrogen, which will trigger the respiratory center and mimicking what the brain would feel during an episode of acidosis. So these babies will start breathing quite fast and this tachypnea will lead to respiratory alkalosis.
Dr. Luis Umaña:
As the condition progresses, some patients may go into shock and then they might develop a little degree of metabolic acidosis. But again, it's never as significant as you would see in a primary organic aciduria. Inside the neurons, it will cause... And we already mentioned about excitotoxicity but also will affect the glia. And for them, it will cause impairment in their mitochondrial function. It will impair the functioning of the pumps and these will lead to brain edema, which will end up with herniation which is essentially the main cause of death for people with hyperammonemia.
Dr. Luis Umaña:
So our treatment really is to lower the production of ammonia and to shunt it away from the system in an alternate pathway, different from the urea cycle. An important tidbit of information for them is that since the urea is not being synthesized, the BUN of these patients will be abnormally low, even when they are in a crisis of hypoperfusion. So a very low BUN with high ammonia and some degree of alkalosis should make you think that this is a urea cycle defect. And again, many of the things you will not get fast but that BUN, that ammonia. Those will come fast to you.
Dr. Luis Umaña:
The next group of conditions that I would like to bring up are the organic aciduria. These will also present in the neonatal period and the manifestations will be almost identical. These babies will become tachypneic. These babies will have rapid neurological deterioration with vomiting and poor feeding. All of them are associated with the catabolism of branched chain amino acids, which are leucine, isoleucine and valine. And these three will actually end up going through the tricarboxylic acid cycle.
Dr. Luis Umaña:
So they will behave also in some way as an energy deficiency disorder. But what will happen is that these patients will accumulate this organic acid, which can come at different steps during the catabolism of these three amino acids. And the manifestation will cause a very significant metabolic acidosis, will increase anion gap, and the accumulation of ketoacids. And that's what can give to some of these conditions, those particular smells that you read in the books. I would say in my experience, sometimes you can feel it, not always. So the absence of smell should not rule out an organic acidemia.
Dr. Luis Umaña:
Also, because they affect the tricarboxylic acid, they can lead to secondary inactivation of the urea cycle. So that's where they might have a degree of hyperammonemia, but still it's never as severe as in a primary urea cycle defect. The most common disorders in this group are propionic and methylmalonic acidemia mostly undistinguishable when they present to you only as you obtain follow-up labs, which mostly is organic acids in the urine that will let you know that the patient is between either propionic or methylmalonic acid.
Dr. Luis Umaña:
The next disorder is isovaleric acidemia. This one again, same presentation, but it's one that sometimes you can have one of those smells sometimes reported as cabbage or rotten cheese. It depends on really who is smelling it. And then maple syrup urine disease. This one is the most proximal of all, the effect is quite severe. These patients will present with less acidosis, but they present accumulation of ketones that will give the particular smell to the urine. But I would say that more than the urine, this has smell, which is kind of like brown sugar, is better identified in ear wax of the babies. And it's easier to collect ear wax than urine.
Dr. Luis Umaña:
Then again, I would not base my diagnosis just if I can or can't smell it. Another important tidbit of information here is the presence of amounts of ketones. Babies are quite inefficient at making ketones compared with the amount that they use. So significant ketonuria in a baby that looks sick should make us think of the organic acidurias.
Dr. Luis Umaña:
We can go next to some of the disorders that would be associated with hypoglycemia. In this group, we will have especially conditions that are associated with energy metabolism. But one of the conditions that is associated with toxicity, which is galactosemia, can also present with hypoglycemia. The biggest group and probably the one that we see more patients associated with hypoglycemia are the fatty acid oxidation defects. And through newborn screening, we've been seeing that they are much more frequent than we thought.
Dr. Luis Umaña:
Among those, medium-chain acyl-CoA dehydrogenase deficiency or MCAD seems to be the most common and one disorder for which newborn screening has proven to be quite an important tool. Before newborn screening, it was told that 25% of the children would die or have significant neurological injury from a hypoglycemic episode. After the institution of newborn screening, that has come close to zero. In our experience in our clinic, none of our patients has had a metabolic crisis since the newborn screening associated with this specific disorder.
Dr. Luis Umaña:
The manifestations for most of these fatty acid oxidation disorders will present after the baby has been fasting for a few hours. Sometimes in the most severe disorders, it could be seen shortly after birth, especially if the baby has not been breastfed or formula fed in the first few hours, because the stress of birthing can trigger fatty acid oxidation disorder. The manifestations will be significant and rapid hypoglycemia, which often is almost on the undetectable range. We have seen patients that come with glucoses of two, or four, or eight, or even zero. And it will be associated at the same time with significant liver dysfunction and in some disorders, cardiomyopathy and arrhythmia.
Dr. Luis Umaña:
All of these disorders respond quite well to the administration of IV glucose at a physiologic glucose infusion rate. So these babies in the NICU they just receive glucose infusion rates of 6 to 8. And they'll respond in a couple of days. All of the symptoms completely improved. And they often don't need high glucose infusion rates. And as long as you keep the baby fed often, the metabolic pathway is not engaged in most cases and the manifestations resolve.
Dr. Luis Umaña:
One thing is that in many of these disorders, the production of ketones is impaired. This is a little bit more significant when you see it in older kids, but still in babies you could see that there's very low production of ketones if you were to measure them during an episode of hypoglycemia. And then again, the main goal is to keep these babies fed in a routine avoiding prolonged fasting and then their prognosis improves quite markedly.
Dr. Luis Umaña:
The next group of conditions in this same group will be the glycogen storage disorders. And I'll break them up because the hypoglycemia in these patients is much earlier than in the patients with fatty acid oxidation disorders. So it happens after one or two hours after a regular fast in an older kid, but can happen after one hour or so in a newborn. And there can be a degree of acidosis, especially because these patients will develop ketones or they might go into a period of lactic acidosis just trying to engage all their alternative pathways to generate glucose. In newborns, hepatomegaly that is characteristic for these disorders might not be noticeable, but in older children it will be.
Dr. Luis Umaña:
Another condition in many of these children is that they can become resistant to hypoglycemia. So we often see babies or children aged three or four that have developmental delay and hepatomegaly and hypotonia. And then when we started examining them or the gastroenterologist perform a biopsy, we'll find accumulation of glycogen in the liver. And then if you do studies on them, you see that, especially at night, they might be becoming hypoglycemic, but they don't present any symptoms. Their brain has just become used to it in the sense that they don't respond with sweats or nightmares or chills, but still their neurons are suffering and that explains why they had developmental delays.
Dr. Luis Umaña:
Again, they respond quite well to glucose at a physiologic infusion rate. So they don't need massive amounts of glucose. They do not respond to glucagon, as the main effect of this hormone is to release glucose from glycogen. In these patients, glucagon actually could worsen some of the symptoms such as lactic acidosis. And the management again is just frequent feeding and sometimes depending on the age, we have to add different compounds to allow for a more continuous release of glucose and avoid either storage of glycogen... So we try to avoid hyperglycemia as well as hypoglycemia, which we mentioned before. We need to halt the metabolic instability and neurological injury.
Dr. Luis Umaña:
Then I would say galactosemia is the other one that pops up quite often in the differential for everyone. This one can present with hypoglycemia, liver dysfunction, but often jaundice is one of the bigger markers. We all have been trained in the use of urine reducing substances to pick up galactosemia. It's an okay test, it's not great, it's not sensitive, it's not specific. So it can be positive for many reasons and it could be even negative in some patients with galactosemia.
Dr. Luis Umaña:
So this is one for which luckily the newborn screening results could be available soon enough that we could intervene. For some of the other disorders, the newborn screening might come and help us specify the diagnosis, but still we would have to be working in the dark for a little bit longer. For galactosemia, usually the results can be at an appropriate time and that will allow us to prevent more serious manifestations.
Dr. Neeta Goli:
And you mentioned that the children with galactosemia would present with jaundice. Would you expect that to be direct or indirect typically?
Dr. Luis Umaña:
It's often both, it’s mixed. It’s both conjugated and unconjugated and it can change as the liver dysfunction progresses. The predominance is for conjugated (direct) hyperbilirubinemia.
Dr. Neeta Goli:
Okay.
Dr. Luis Umaña:
And again, it's not a good marker, it's not like everyone with jaundice will be... I would say that it's a little bit more of the conjugated one that increases, but using the urine reducing substances could give you an index of suspicion, but I would not put my eggs in the basket just because of it. Galactosemia tends to be quite difficult to suspect in the newborn period and that's why I rely a lot on the newborn screening to pick it up.
Dr. Luis Umaña:
I would say also that disorders in which the hypoglycemia tends to be resistant to management where you need to have high glucose infusion rate, should make you think more of an endocrine disturbance than a primary inborn error of metabolism. And that's an important question that we often have to discuss with our colleagues in the NICU or in the nursery, because even though many of these endocrine disorders have a genetic base, management might be different.
Dr. Neeta Goli:
What kind of endocrine disorders are you discussing specifically?
Dr. Luis Umaña:
One of the common ones that we see is hyperinsulinism. You could have hyperinsulinism both from genetic causes affecting some of the receptors at the level of the pancreatic islet. But at the same time in some patients, you could have a hyperinsulinism that can be triggered by immaturity. Many newborns can have a degree of hyperinsulinism and you'll see that often you're pumping a lot of glucose just to keep that glucose stable. Interestingly, sometimes that sends you in a spiral because the more glucose you... Like the more stimulated that islet will be, then the more insulin it will produce. And it's a difficult cycle to get out of because if you lower the GIR, the patient will become hypoglycemic and symptomatic. So sometimes, you'll have to do it quite slowly and might take you days or even weeks to correct sometimes. Other disorders you can see some adrenal insufficiencies. Some babies could have it just for prematurity or for the need for steroids for longer periods of time. Hypopituitarism can also present with significant hypoglycemia that could also be resistant to glucose infusion just because again, the hormones are not there to lead to the incorporation of glucose into the cells.
Dr. Neeta Goli:
Okay.
Dr. Luis Umaña:
Going back to some of these disorders we didn't think when we discussed inborn errors of metabolism, the next group are the amino acidopathies. The amino acidopathies behave somewhat different than the disorders that we discussed, in the fact that their manifestations can be more chronic, such as in the case of phenylketonuria or homocystinuria. These babies will not become sick in the nursery or the NICU and they will not show any significant symptoms that you could identify or nothing that will make you suspect that there's anything going on with these babies. We identify them through the newborn screening. And then they would need chronic management through their life to prevent this accumulation of phenylalanine or homocysteine to have those toxic effect.
Dr. Luis Umaña:
One amino acidopathy that could present with an acute or chronic manifestation is tyrosinemia type I. This is one in which... It's not the amino acid itself that is toxic, but it's actually a downstream metabolite that is called succinylacetone. And that can lead to liver dysfunction, can lead to renal dysfunction, and in untreated patients will lead also to a very early hepatic adenocarcinoma. So patients need to start treatment before the age of six months to limit this risk. Patients that have not been treated by the age two have probably a 95 to 100 percent risk of developing adenocarcinoma liver dysfunction. Patients who are treated very early in life will become the same as the general population.
Dr. Luis Umaña:
So this is one that could still be found in the NICU. Again, this is one that we could begin to suspect, or we suspect with the newborn screening because it's designed to measure the levels of tyrosine and that can help us to intervene very early on into this condition. So most of them, I think about most of the common bigger groups that we think when we think of inborn errors of metabolism.
Dr. Luis Umaña:
The next group are the mitochondrial disorders, this is the only one that we often get inquired about and that we often get worried about for babies who are sick in any setting, could it be NICU, many patients are in the ICU, some patients in the regular floor, some patients might call on the clinic with very specific symptoms. They often have more systemic involvement. Lactic acidosis is considered the hallmark of most of these conditions, but I have seen it absent in many cases, and it will depend on which of the specific mitochondrial pathways is affected.
Dr. Luis Umaña:
These patients can have developmental delays, myopathy, some might have mild levels of liver dysfunction or renal dysfunction. So every organ that uses a lot of energy, might show you some symptoms. Sometimes, it will be organ-specific. So in many conditions, you will only have neurological symptoms, or myopathic symptoms, or cardiac symptoms. Some will be much more extensive. And really, there's no specific markers that can allow us to detect, "Oh, is this A, or B, or C mitochondrial condition." And often we would like to do molecular analysis, which takes such a significant amount of time. And the treatments for this condition are the same as the diagnosis tend to be more symptomatic for each pathway. Prognosis is more variable.
Dr. Luis Umaña:
And again, I think that there are the bigger groups that I would consider a list in the fact that this may be the most treatable disorders. Again, we could then discuss about the complex molecule disorders, especially with the storage disorders. These are more chronic. So these are children that will present with symptoms that accumulate slowly over time. Some of them might have dysmorphism, which for most metabolic disorders is not common, but for these specific accumulation disorders... Especially visceromegaly or changes in their facial appearance over time can be seen and slow neurological deterioration. And that slow, I would put an asterisk because as low as some patients might deteriorate in a period of one year. Some patients might take many years. Some patients already have symptoms by the time they are born. But you could see that there's a progression as they live more and more. But they often don't have acute metabolic crisis compared with the other two groups of disorders, the accumulation of toxic compounds or the energy deficient disorders.
Dr. Luis Umaña:
I should say that we must have inborn errors of metabolism in our differential, but not let them being in our differential cloud us from more common conditions. Some of the most common causes of metabolic of lactic acidosis really is hypoperfusion either from sepsis, from prematurity, from cardiac disease. And these can also lead in some cases, for example, to what we call secondary mitochondrial injury in which those mitochondria that were damaged with hypoxia will release some of their compounds into the bloodstream and you could see them, high lactic acid or some of the compounds that overtime will recover. And we see that with much more frequency than primary mitochondrial disorders.
Dr. Luis Umaña:
So more or less, that will be in a nutshell, if I were trying to compile some of the most common disorders. But again, it's not an easy task to do one, it will take a lot of expertise and trying to pick up clues in different places. I would say the most important thing is to try to identify these babies, try to treat them. I would say most of them actually respond to what we call induction of anabolism, which we can achieve by giving them IV glucose and getting proper labs, both from your routine labs just as blood gases, comprehensive metabolic panel that would include your liver and renal function as those can give you a lot of information, I would say. Ammonia and lactic acid, those are two, I would say quicker labs, you need to know how to draw them and send them properly to your lab because otherwise you can get false elevations that could just derail your assessment of these babies.
Dr. Neeta Goli:
And for our listeners, can you just quickly tell us in terms of the collection for those two, just so they know what to expect.
Dr. Luis Umaña:
So often for both of those, for ammonia and lactic acid, we advise against the use of a tourniquet because that can increase the levels of both of them just by either hemolysis or there's more ischemia that can be left during the period of the tourniquet. Also, we recommend to put those labs in ice and be taken STAT to the lab. That will prevent, especially the blood cells, to continue their metabolism, which again would release them into the bloodstream and increase them because once the blood is out of your system, there is not a liver that will process those two chemicals. So they could start accumulating in blood that has been standing.
Dr. Luis Umaña:
And that is often my recommendation for both of those. So free-flowing vein preferably, arterial sticks are acceptable. You can do it from an arterial stick and put on ice and taking the STAT to the lab. Many times, some of us when we were training, we would go ourselves to the lab rather than rely on the tube systems. But in bigger hospitals, the tubes might be faster.
Dr. Luis Umaña:
Sometimes, ICUs have their own processing labs very close and I will rely on those. Sending patients to do it in an outside outpatient lab, I often don't rely on it as much because there's less reliability on the handling of that samples than what would happen in the hospital. But if you have a suspicion you can always do it.
Dr. Neeta Goli:
Okay. That was very helpful, I think in giving us the presenting signs and manifestation of each of these classes and a nice way to organize them all in our heads. Again, like you said, in a nutshell, there's a lot more we could go into, but that was really helpful. Dr. Umaña, was there anything else that you wanted to discuss about the classification of newborn metabolic disorders?
Dr. Luis Umaña:
I think again, just reinforcing, finding out what is your leading symptom, is it hyperammonemia? Is it hypoglycemia? Is it the acid-base disturbance? Or is it lactic acidosis? Can help you go into any of these groups. The newborn screening is a very important tool for you. So check those screens, they might have some answers for you. At the same time, they might help you rule out things. For many of these disorders, you would not expect to have normal newborn screens. So if they are normal, maybe you can start looking elsewhere. And again, we in Genetics are always open and more than happy to help you guys whenever there's any question or any concern. And as I said, there's over 1000 disorders, not even us know all of them. And sometimes, finding the specific answer might not be fast. But the treatable ones are the ones that we try and we are better at identifying sooner.
Dr. Neeta Goli:
Okay. Thank you. So this concludes part one on the classification of newborn metabolic disorders. Please join us for the next episode for part two when Dr. Umaña will return to discuss the evaluation and management of these disorders. To end today's episode, do you have any advice for our listeners while they're taking care of newborns?
Dr. Luis Umaña:
Always rely in your own exam but only when you've been told, but go and look at the baby, examine the baby. Keep inborn errors of metabolism in your differential, but at the same, don't let it cloud all of your other points on the differential. I often say every question should have a simple answer and the more difficult the question, the simpler the answer should be.
Dr. Neeta Goli:
I like that. Okay, thank you so much for joining us today, Dr. Umaña.
Dr. Luis Umaña:
You're welcome and thank you for having me.
Dr. Neeta Goli:
Thanks for listening to Newborn News. We hope you join us next time. If you like what you hear, make sure to subscribe and leave us a review. If you have questions, comments, feedback, or suggestions for future episodes, please email me at NewbornNews@utsouthwestern.edu. As a reminder, this content is educational and is not meant to be used as medical advice. Views or opinions expressed in this podcast are those of myself and my guests and do not necessarily reflect the views of the university.