Metabolic Flashcards
Metabolic Conditions (21 cards)
What is homocystinuria often characterized by?
Physical appearance similar to Marfan syndrome, long slender extremities, scoliosis, dislocated ocular lenses
Both disorders share these physical traits, but they have distinct differences in lens subluxation.
How do the lens subluxations differ between Marfan syndrome and homocystinuria?
Marfan syndrome has upward subluxation; homocystinuria has downward subluxation
What additional symptoms are common in individuals with homocystinuria compared to Marfan syndrome?
Intellectual disability, psychiatric illness, thinning of lightly pigmented skin, malar flushing, livedo reticularis, coarse light hair
What risk is increased in patients with homocystinuria due to weakened collagen structure?
Vascular thrombosis
What complications can arise from vascular thrombi in homocystinuria?
Stroke, myocardial infarction, pulmonary embolus
What causes the intellectual disability in homocystinuria?
Vascular thrombi that reach the central nervous system
What cardiovascular issues are not associated with homocystinuria?
Aortic root dilatation and mitral valve prolapse
What genetic inheritance pattern does homocystinuria follow?
Autosomal recessive
What enzyme deficiency leads to homocystinuria?
Cystathionine ß-synthase
What happens to homocysteine in the blood of patients with homocystinuria?
Accumulation of homocysteine
How is excess homocysteine managed in the body?
It is reconverted into methionine
What might newborn metabolic screening tests identify in relation to homocystinuria?
Elevated blood levels of methionine
What percentage of patients with homocystinuria respond to pyridoxine treatment?
About 50%
What is the typical dosage range for pyridoxine in treating homocystinuria?
100-1,000 mg/day
Why is close monitoring of dietary intake of protein important in homocystinuria patients?
Especially those who do not respond to pyridoxine
What are the symptoms of Angelman syndrome?
Seizures, intellectual disability, microcephaly, ataxia, hand-flapping behaviors, puppet-like gait
What are the characteristic findings of Williams syndrome?
Periorbital fullness, down-turned lower lip, friendly personality, stellate pattern of iris, strabismus, supravalvular aortic stenosis, intellectual disability, risk for hypercalcemia
What common features are associated with Noonan syndrome?
Short stature, congenital heart defects, pectus excavatum, webbed neck, hypertelorism
What are the common features of DiGeorge syndrome?
Cleft palate, velopharyngeal incompetence, anomalies of auricle, thymus agenesis/hypoplasia, parathyroid gland hypoplasia, cardiac abnormalities
What are the most common cardiac abnormalities in DiGeorge syndrome?
Tetralogy of Fallot, interrupted aortic arch, ventricular septal defect, truncus arteriosus
What behavioral problems are associated with DiGeorge syndrome?
Short stature and behavioral problems
