Disorders of Carbohydrate Absorption, Transmembrane Transport and Metabolism

TY - CHAP

T1 - Disorders of Carbohydrate Absorption, Transmembrane Transport and Metabolism

AU - Derks, Terry

AU - Lubout, Charlotte

AU - Woidy, Mathias

AU - Santer, Rene

PY - 2022/1

Y1 - 2022/1

N2 - Carbohydrates are an important source of energy in thehuman organism. Within the body, glucose is the mostabundant monosaccharide that can be stored as glycogen,a branched polymer with a protein core (glycogenin),mainly in liver and muscle. Inborn errors of metabolismmay affect the uptake, distribution and reabsorption of monosaccharides in different organs, a process that ismeticulously regulated by a system of transporter proteins.Congenital disorders may impair the intestinaldigestion of disaccharides and the conversion of monosaccharides(fructose, galactose) into glucose. They canfurther affect glycogen synthesis, glycogen breakdown(glycogenolysis), glucose metabolism to acetyl-CoA(glycolysis) and de novo synthesis of glucose(gluconeogenesis).Glucose absorption and transport disorders presentwith a very variable clinical picture depending on whichof the organ- and substrate-specific transporters isaffected. Likewise, disorders of galactose and fructosemetabolism affect different organs due to the accumulationof toxic intermediates. After the introduction of thesemonosaccharides with the diet, impaired liver function isfrequently among the first signs.Glycogen storage diseases can be divided into thosemainly presenting with hepatic manifestations (hepatomegaly,fasting intolerance, hypoglycaemia) and thosewith muscular presentations (exertion intolerance, rhabdomyolysis).Some show a combination of these symptoms,cardiomyopathy may be an additional feature andfurther accompanying signs, for example, haemolyticanaemia, may be observed depending on tissue distributionof the affected protein.Management of most carbohydrate disorders requiressymptomatic measures, supportive care and a multidisciplinaryapproach. In some conditions, dietetic treatment ispossible which may have its basis in an exclusion of certaindi- or monosaccharides. Outcome, however, is highlyvariable and mainly depends on the underlying type ofdisorder. Causal treatment is not available for most diseasesand for some patients, organ transplantation (liver,kidney, heart) is an option. Experimental treatments mayinclude enzyme replacement therapy (available, e.g., forlysosomal α-glucosidase deficiency, GSD-IIa) and genetherapy.

AB - Carbohydrates are an important source of energy in thehuman organism. Within the body, glucose is the mostabundant monosaccharide that can be stored as glycogen,a branched polymer with a protein core (glycogenin),mainly in liver and muscle. Inborn errors of metabolismmay affect the uptake, distribution and reabsorption of monosaccharides in different organs, a process that ismeticulously regulated by a system of transporter proteins.Congenital disorders may impair the intestinaldigestion of disaccharides and the conversion of monosaccharides(fructose, galactose) into glucose. They canfurther affect glycogen synthesis, glycogen breakdown(glycogenolysis), glucose metabolism to acetyl-CoA(glycolysis) and de novo synthesis of glucose(gluconeogenesis).Glucose absorption and transport disorders presentwith a very variable clinical picture depending on whichof the organ- and substrate-specific transporters isaffected. Likewise, disorders of galactose and fructosemetabolism affect different organs due to the accumulationof toxic intermediates. After the introduction of thesemonosaccharides with the diet, impaired liver function isfrequently among the first signs.Glycogen storage diseases can be divided into thosemainly presenting with hepatic manifestations (hepatomegaly,fasting intolerance, hypoglycaemia) and thosewith muscular presentations (exertion intolerance, rhabdomyolysis).Some show a combination of these symptoms,cardiomyopathy may be an additional feature andfurther accompanying signs, for example, haemolyticanaemia, may be observed depending on tissue distributionof the affected protein.Management of most carbohydrate disorders requiressymptomatic measures, supportive care and a multidisciplinaryapproach. In some conditions, dietetic treatment ispossible which may have its basis in an exclusion of certaindi- or monosaccharides. Outcome, however, is highlyvariable and mainly depends on the underlying type ofdisorder. Causal treatment is not available for most diseasesand for some patients, organ transplantation (liver,kidney, heart) is an option. Experimental treatments mayinclude enzyme replacement therapy (available, e.g., forlysosomal α-glucosidase deficiency, GSD-IIa) and genetherapy.

M3 - Kapitel

SN - 978-3-030-67726-8

SP - 649

EP - 700

BT - Physician’s Guide to the Diagnosis, Treatment, and Follow-Up of Inherited Metabolic Diseases

A2 - Blau, Nenad

A2 - Vici, Carlo Dionisi

A2 - Ferreira, Carlos R.

A2 - Vianey-Saban, Christine

A2 - van Karnebeek, Clara D. M.

PB - Springer Nature Switzerland

ER -