Variants of metabolism Flashcards
(24 cards)
What is the estimated incidence of metabolic disorders?
Approximately 1 in every 2500 births
This represents about 10% of all monogenic conditions in children.
What percentage of morbidity and mortality is attributed to metabolic disorders?
A substantial percentage
Metabolic disorders account for significant health impacts directly related to genetic disease.
What are some common diseases that different alleles of genes encoding enzymes can influence?
- Diabetes
- Heart disease
- Stroke
- Cancer
What is classic phenylketonuria caused by?
Defect in phenylalanine metabolism
This defect is linked to the enzyme phenylalanine hydroxylase.
What is the prevalence of classic galactosemia?
1/35,000 to 1/60,000
What is the mutant gene product for hereditary fructose intolerance?
Fructose 1,6-bisphosphate aldolase
What is the chromosomal location for phenylketonuria?
12q24
What type of inheritance pattern do most metabolic disorders follow?
Autosomal recessive pattern
What common screening test is used for metabolic disorders in newborns?
Testing for elevated levels of metabolites in dried blood
What is a significant challenge in diagnosing metabolic disorders?
Variability in presentations
True or False: Carrier states for most metabolic disorders typically cause morbidity.
False
What is the common presentation of metabolic disorders after birth?
Symptoms can range from sudden onset to insidious changes over time
What are the symptoms observed in the case of Anthony, the 9-month-old boy?
- Irritability
- Vomiting
- Sleepiness
- Hypoglycemia
- Hyperammonemia
What condition was Anthony ultimately diagnosed with?
Reye syndrome
What treatment was initiated for Maria, the 6-month-old girl with MCAD deficiency?
- Intravenous glucose
- Oral carnitine
- Avoidance of fasting
What can vary significantly in individuals with the same metabolic disorder mutation?
Phenotypic variability
What should supportive therapy be initiated for before making a diagnosis?
Metabolic disorders
What implications can a specific diagnosis of a metabolic disorder have for a family?
- Prenatal testing
- Presymptomatic therapy
What is the prevalence of MCAD deficiency?
1/1000 to 1/15,000
What is the main metabolic defect in MCAD deficiency?
Defect in fatty acid oxidation
What is the chromosomal location for cystathionine β-synthase in homocystinuria?
21q2
What type of disorders are classified under ‘Energy Production Defects’?
- Cytochrome c oxidase deficiency
- Pyruvate carboxylase deficiency
- Pyruvate dehydrogenase complex deficiency
What is the rare disorder associated with a defect in ornithine carbamyl transferase?
Ornithine transcarbamylase deficiency
What is the prevalence of Wilson disease?
1/50,000
