00:01 In this presentation, we're going to talk about Inborn Errors of Metabolism. 00:06 And this is just going to be an overview because there are many. 00:10 So what are Inborn Errors of Metabolism. 00:14 This is a congenital condition, and it's the absence or abnormality of an enzyme, or that enzymes cofactor. 00:24 So what does that mean for our patient? We have many substances in our bodies, and many that we take in like protein, for example. 00:34 And you need enzymes or the cofactor of those enzymes to break those substances down so that our body can use them. 00:43 When these substances are not able to be broken down, because there's a deficiency of an enzyme or the cofactor, what happens is we get an accumulation of metabolites or an accumulation of those substances in the body. 00:58 And that can have really extreme consequences. 01:03 Now, sometimes, if the enzyme is missing or abnormal, we'll actually have a deficiency of the metabolites. 01:10 We don't have the substances in the body that we need for our metabolism and for general functioning. 01:18 So what causes an inborn error of metabolism? These are mostly autosomal recessive. 01:25 So this means if you remember from your genetics, that the offspring is going to inherit two copies of the gene, one from each parent. 01:33 And the genes usually come from non sex chromosomes. 01:36 And those copies must both have the condition that's going to cause the inborn error. 01:44 So there are many types of inborn errors of metabolism. 01:48 And I want to stress that you do not need to know each inborn error. 01:54 There's some broad categories of these inborn errors. 01:57 You'll see organic acidemia or amino acid disorders. 02:03 And these cause specific diseases. These also have categories. 02:08 So you might have a lysosomal storage disease. 02:12 A disease like phenylketonuria, where you have too many ketones in your body. 02:18 There's peroxisomal disorders, mitochondrial diseases, where your mitochondria just are not working correctly. 02:28 Glycogen storage diseases. 02:31 And we know if you have trouble storing glycogen that you're going to have trouble with your metabolism. 02:37 Urea cycle disorders. 02:40 So there are many different types. 02:43 So, inborn errors of metabolism can either be a single enzyme deficiency and that's the most common thing that happens or you might have abnormalities in more than one enzyme. 02:54 And when you have abnormalities in more than one, you're usually going to affect several metabolic steps. 03:02 So what does this mean for our patients? When you have a single enzyme deficiency, which is the most common, you might have an accumulation of metabolites. 03:12 An example of this would be Alkaptonuria. 03:16 And this results in an accumulation of homogentisic acid. 03:22 You might have a deficiency of metabolites as what happens in the MCAD disease, and that is going to result in an inability for the body to make keto acids. 03:35 Additionally, if you have abnormalities in more than one enzyme, as in the case of vitamin B 12 transport and synthesis, you might have an accumulation of methylmalonic acid and homocysteine. 03:49 So this affects multiple steps in the metabolism. 03:53 So how often does this happen? It turns out that the individual inborn error rates is actually pretty rare. 04:00 It's low, it's less than 100,000 live births. 04:04 But when you combine this with the fact that there are many, many different types of inborn errors of metabolism, it actually becomes a little more common. 04:13 So one in 800 to 2500 live births, depending on where you are, may have an inborn error of metabolism. 04:24 So what are patients going to look like if they have inborn errors? Well, when your metabolism is affected, it's going to include findings in almost every body system. 04:35 Primarily what we're going to notice first our problems with the neurologic system and with the gastrointestinal system. 04:43 So you might see things and especially chronic symptoms like failure to thrive and growth delay. 04:50 Maybe these patients aren't getting their developmental milestones. 04:53 They have a developmental delay, or they might even lose developmental milestones. 04:59 Infants that were able to sit up and smile at you now no longer have the ability to sit on their own. 05:05 So that's what is meant by regression of milestones. 05:09 They might experience cardiomyopathy, they might have hepatomegaly. 05:13 So their liver is really big. 05:14 You can feel it way down below their ribs. 05:17 They might have spastic diplegia, meaning that they have difficulty walking. 05:23 More acute symptoms are going to be symptoms that are consistent with shock. 05:28 So you might have dehydration. 05:30 They might be hypoglycemic, making them shaky. 05:33 They might be in a prolonged fasting state, because they just haven't been able to eat because they're nauseous, and they're vomiting. 05:41 And they are under extreme amounts of stress. 05:46 So that can progress into a metabolic emergency. 05:51 If your patient is continually vomiting, they're becoming lethargic. Maybe even falling into a coma. 05:58 Experiencing seizures, or rapid deep breathing. 06:02 That is all metabolic emergency. 06:05 Additionally, they might be breaking down their own muscles, which is rhabdomyolysis. 06:10 Might be experiencing hypothermia. 06:13 Hypothermia is often associated with more minor illness and then hyperthermia or high temperatures might follow that. 06:22 If you have a patient that has any of these symptoms that can't be explained by an illness or other condition, we have to consider the possibility of an inborn error of metabolism. 06:35 Inborn errors can really occur in any age group. 06:38 But the most severe forms are usually going to be found as a neonate.
The lecture Inborn Errors: Overview (Nursing) by Amy Howells, PhD, CPNP-AC/PC is from the course Inborn Errors of Metabolism – Pediatric Nursing.
Which pediatric client does the nurse suspect is experiencing a metabolic emergency due to an inborn error?
Which symptoms are consistent with an acute presentation of inborn errors of metabolism? Select all that apply.
Which is true about inborn errors?
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