Genetic Metabolic Disorders Flashcards
PKU
(disorder of AA met)
- Phenylketonuria
- Deficiency of phenylalanine hydroxylase
- Phe not metabolized into tyrosine
PKU MNT
- restrict Phe
- supp Tyr
- monitor blood Phe levels
- 3 day food/formula record prior to blood tests
Maternal PKU
(disorder of AA met)
- fetus exposed to higher amounts of Phe
Maternal PKU MNT
MNT is complex (need essential AA for dev., but too much = suboptimal brain dev)
- Monitor blood Phe
- limit Phe while providing adequate nutrients
- medical food with Phe removed
Maple syrup urine disease
(disorder of AA met)
AKA branched-chain ketoaciduria
- branched chain alpha ketoaciduria hydroxidase complex (BCAKD)
- inability to metabolize BCAAs especially leucine
leu, ile, val
Maple syrup urine disease MNT
- Monitor BCAA levels and growth
- special formula supplemented with infant formula or breast milk
- gradually reintroduce BCAAs when Leu decreased
Proprionic acidemia
(Disorder of organic acid met)
- defect of proprionyl-CoA carboxylase
- end up with a buildup of proprionic acid in the blood
Proprionic acidemia MNT
pharmacologic doses of biotin
Methylmalonic acidemia
(disorder of organic acid met)
- defect of methylmalonyl-CoA mutase apoenzyme
- end up with build-up of methylmalonic acid
Methylmalonic acidemia MNT
pharamcologic doses of B12 > to help the enzyme function optimally
Ketone utilization disorders
(disorder of organic acid met)
- disorders of isoleucine and ketone body metabolism
Ketone utilization disorders MNT
- restrict dietary protein
- supplement with L-carnitine
- Avoid fasting
L-carnitine > helps remove fatty acids metabolites in the blood and promotes their excretion
Ornithine transcarbamylase (OTC) deficiency
(disorders of urea cycle met)
Citrullinemia
(disorders of urea cycle met)
Arginosuccinic aciduria
(disorders of urea cycle met)
Carbamyl-phosphate synthetase deficiency
(disorders of urea cycle met)
MNT for Disorders of urea cycle metabolism
- Restrict PRO and only use BV PRO
- Infant PRO- 1-1.5g/kg/d
- Child- 1-2g/kg/d
- Supp- L- arginine unless arginase def
- Arginine helps excrete excess nitrogen
Galactosemia
(disorder of CHO met)
- inability to convert galactose to glucose
- build-up of galactose in the bood
Galactosemia MNT
- avoid lactose-containing products and certain fruits and vegetables
- soy infant formula
Examples of galactose containing F&V
Dates papayas bell peppers persimmons tomatoes watermelon
Glycogen storage disease
(Disorder of CHO met)
- inability to metabolize glycogen to glucose
- Hypoglycemia
Glycogen storage disease MNT
- High complex CHO diet (also equal distribution throughout the day)
- cornstarch administration and iron supplementation (cornstarch can inhibit iron absorption)
Medium-chain acyl CoA dehydrogenase deficiency (MCAD)
(disorders of fatty acid oxidation)
- lack of enzymes to break down MCFAs
- Happens when fasting or ill
- Hypoglycemia
- Absence of urinary ketones
Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCAD)
(disorders of fatty acid oxidation)
- lack of enzyme to break down LCFAs
- Happens when fasting or ill
- Hypoglycemia
- Absence of urinary ketones
MNT for disorders of fatty acid oxidation
- avoid fasting
- use three meals plus snacks (especially before bed)
- use high CHO, low fat diet
- supplement with L-carnitine (helps with fatty acid oxidation; removes toxic metabolites from bloodstream through urine)
