Inborn Errors of Metabolism: Metabolic Pathways

00:02 In this lecture we're going to discuss, Inborn Errors of Metabolism in Children.

00:06 This is a very complicated field.

00:08 There are experts who specialize in this alone.

00:11 We're gonna try and shed some light in the complexity of this and give some examples of errors of metabolism, and hopefully make it a little bit easier to understand.

00:22 So here is glucose, this is the essential building block with which we use to create all the energy we need to run our bodies.

00:32 As you recall from biochemistry, glucose will be stored in the liver as glycogen store, in glycogen.

00:40 Patients can have problems with storage of glycogen.

00:44 This family of metabolic disorders are glycogen storage diseases.

00:47 We'll talk about those.

00:49 Glucose is broken down into pyruvate through glycolysis and of course in the other direction we have gluconeogenesis.

00:58 It is important to understand that that breakdown can very rarely have some problems.

01:04 But that?s pretty rare because you can imagine that if you're having a problem with glycolysis it's pretty hard to get by.

01:11 Glucose also is sent over to something called the pentose phosphate shunt.

01:16 The pentose phosphate shunt is responsible for making NADPH and there is a disorder, G6PD, which can cause problem with creating NADPH.

01:28 Because that diseases symptoms are almost entirely limited to red blood cells, I wanno talk about G6PD during the hemo lectures which you'll see later.

01:39 Pyruvate is sent through the Krebs cycle to create ATP, the energy for which most of our protein processes occur.

01:47 Don?t forget, that?s also how we can feed into the fatty acid metabolism pathway and we'll talk about some diseases of fatty acid metabolism as well.

01:58 Also, during fatty acid metabolism that?s how we make ketones.

02:04 Patients may have problems making ketones and we'll talk about some conditions there as well.

02:10 The pyruvate is typically also sent over to start with amino acid metabolism.

02:16 Both metabolizing but even more perhaps handling amino acids can be a problem with patient with amino acid disorders.

02:26 Some patients who have certain amino acids, that they have a hard time digesting or managing in an effective way.

02:33 And don?t forget, amino acids may be disposed off and in particular the nitrogen in amino acids is disposed off through the urea cycle.

02:43 And patients can absolutely have urea cycle defects and we'll talk about some of those as well.

02:49 So this is the overview for metabolic pathways, and we're gonna focus on some common deficiencies in these pathways.