Metabolic
Terms
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- Traditional neonatal galactosemia presentation
- vomiting, lethargy, depression, jaundice, HS megaly. Gram - sepsis
- Presentation of glycogen storage disease.
- hepatomegaly, late infancy presentation when child sleeps through the night. hypoglycemia.
- Peroxisome disorders
- very long fatty acid metabolism error. two types, peroxisome broken (Zellweger), and enzyme broken (adrenoleukodystrophy). all are ar except ALD which is xr. Congenital bone disfigurement
- AD familial hypercholesterolemia
- High cholesterol, xanthomas, CAD. elevated choleseterol in 1st yr of life. Initiate meds once elevated. Xanthomas by teens, 20s
- Homocystinuria
-
similar to Marfans (tall thin, pectus, blonde, scoliosis, flat feet, dislocated lens), scoliosis, thromboembolus is major complication.
Pyridoxine improves 1/2 of patients. Often don't present until age 3 when lens dislocation occurs - high ammonia and ketoacidosis suggests what
- organic acidemia. Dx by serum amino acids and urine organic acids. associated with thrombocytopenia, neutropenia, hypoglycemia. methylmalonic, propionic
- hi ammonia and respiratory alkalosis suggests
- urea cycle defect. dx by serum amino acids
- porphyrias
- AD defects in porphyrin creation. porphyrins are Fe binding molecules like heme. photosensativity and abdominal pain are the most common sx. Stool porphyrin levels.
- mucopolysaccharidosis
- late infancy. coarse face, organomegaly. urine mucopolysaccharide concentration.
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Chorionic Villus Sampling timing
Amnio timing -
CVS 10 wks
Amnio 14-16wks - Tay - Sachs
- ar, lysosomal enzyme deficiency. Hexosaminidiase A6-9 mo normal, then hypotonia, delays, exagerated startle
- maternal PKU uncontrolled
- spontaneous abortion. MR, microcephaly, congen heart, low birthweight.
- Glycogen storage disease type I
- von Gierke d. glucose-6-phosphatase deficiency. So liver cannot produce glucose by glycolysis or gluconeogenesis. Glucose derived from GI tract alone. gives 2hr stores. Doll's face. hepatomegaly from liver trying so hard. Hypoglycemia. NG drip glucose at night until 2yrs then give raw corn starch at night
- nonglucose reducing substances
- galactosemia or fructose intolerance
- hypoglycemia, no reducing substtances or ketones
- gluconeogensis error, like glycogen storage disease.
- PKU masquarader
- tetrahydrobiopterin deficiency. cofactor to PKU. these infants fail to improve on PKU diet. need tetrahydrobiopterin, dopamine, serotonin supp in addition to PKU diet.
- 24hrs of life, hypotonia, hypoglycemia, hi ammonia,
- urea cycle defect
- urea cycle disorders, genetics and sx.
- ar except OTC which is X linked. sudden and profound hypotonia on day 2 of life. hi ammonia.
- Urea cycle defect labs
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hi ammonia
respiratory alkalosis
lactic acidosis
no ketonuria - Organic acid defect labs
-
hi ammonia
hi lactic acid
ketonuria - Wolman disease
- lipoprotein metabolism error. first few wks of life. vominting, diarrhea, malabsorption, FTT, HS megaly. adrenals large and calcified.
- Beckwith Wiedemann sx
- macrosomia, macroglossia, vsceromegaly, glabellar nevus simplex, large umbilical hernia or omphalocele
- type of hypoglycemia in Beckwidth
- pancreatic islet cell hyperplasia causing hyperinsulinemia.
- differentiate Beckwidth from IDM
- no macroglossia, umbilical hernia or omphalocele in IDM. both have islet cell hyperplasia.
- Treatment for neonatal hyperinsulinemia causing hypoglycemia
- Diazoxide
- Signs s of fatty acid ox defect
- hypoglycemia, tachypnea, met acidosis with anion gap , normal CBC. Occurs when babies sleep through the night and need fat.
- fatty acid ox labs
- carnitine complexes with long fats to get into mitochondira. Because not broken down, they build up as acylcarnitines and are excreted in urine. No ketones formed (ketones are end result of fatty acid ox. absence of ketones, elevated acylcarnitines in blood and urine.
- reducing substances
- elevated in glycogen storage disease. almost always presents by 4 months.
- MSUD
- branched cahin amino acid degredation error. Normal at birth. develops coma, vomiting, and rigidity (hypertonic) after about a week. Looks like sepsis. hypoglycemic. Needs removal of branched chainaa by PD.
- ammonia suggests what
- ammonia is from the degredation product of amino acids. Amino acid processing disorder (anion gap acidosis), urea cycle defect (no acidosis). occurs after first protein feed. transient hi ammonia (40-50) in preterm infants is normal.
- Canavan Disease
- ar N-acytlaspartic acid builds up in white matter. large amounts in urine. White matter dies. Ashkenazi. normal birth. 3-6 mo old macrocephaly, severe hypotonia, head lag. delayed milestones.
- fatty acid oxidation errors
- fasting hypoglycemia with no ketonuria. Can present with first illness 2-3yrs or at 3 month when sleeping through the night.
- carnitine deficiency
- often carnitine is deficient secondarily. In primary. cardiomyopathy ensues as young child
- familial hypercholesterolemia
- co-dominant. heterozygotes partially affected. hi cholesterol, normal triglycerides. xanthomas on achilles and hand by teen.
- familial combined hyperlipidemia
- routine hi cholesterol and TG. common
- Lipid storage disorders (Lysosomal storage)
- Tay-Sachs, Sandhoff, Niemann Pick, gaucher, Fabry, metachromatic leukodystrophy.krabbe,
- Tay-Sacchs
- 1/25 carrier freq in Ashkenazi, ar, heosaminidase A, loss of motor skills, startle reaction, cherry red spot. 5 mo.
- Sandhoff D
- hexosaminidase B, Same as Tay-Sacchs but with HSmegaly.
- Gaucher Disease
- most common lysosomal storage disorder in Ashkenazi. Bone, Heme, HSmegaly. easy bruising, bone pain, HSmegaly, fatigue from anemia. bone marrow will dx.
- Niemann-Pick
- fatal disorder infantcy, lysosomal storage. FTT, HSmegaly, progressiveneurodegen. loss of milestones
- glycogen storage disease
-
liver glycogen: type I (von Gierke) doll face (cherrubic)
muscle glycogen: Pompe (floppy baby, myopathy), McArdle (muscle cramps, late childhood), - Galactosemia
- lactose is galactose and glucose. E. coli sepsis, and all the usuall neonatal sepsis picture. ar. lifelong galactose elimination.
- Hereditary fructose intolerance
- ar. healthy until fructose or sucrose (fructose-glucose) is ingested. Reducing substance in urine, same as galactosemia
- mucopolysaccharidoses
-
glucosaminolycans not broken down in lysosome. Hurler: normal birth, dx 6m-2y HSmeg, skeletal deform, corase face, large tongue
Hunter: severe, same as Hurler without corneal cloud, mild .
Sanfillipo: hyperactive, MR - Gout
- hyperuricemia, arthritis. primary gout is middle aged men. secondary gout is in kids (rapid tissue breakdown or turnover)
- Lesch-Nyhan
- Self-mutilation mouth, fingers, dystonia. xr, hyperuricemia, MR, CP, choreoathetosis, spasm. nl birth, hypotonic, vomiting. consider in dx of CP when birth hx is normal.
- ketotic hypoglycemia
- most comomoon childhood hypoglycemia. 18m-5y, remits by 9y. prompted by illness or long fast. ketonuria, normal insulin level