Biochem Flashcards
Lactic acidosis
Galactosemias
Avoid legumes
GALT/Gal-1-P Deficiency
Only symptom is cataracts
GALK Deficiency
Dietary lactose and galactose restriction
GALE Deficiency
Galactosemias
GALT/Gal-1-P Deficiency
GALK deficiency
GALE deficiency
Liver dysfunction Renal dysfunction Hypoglycemia Cataracts Dairy intolerance Lactic acidosis Hyperuricemia
General features of Galactosemias
Glycogen storage diseases
Von-Gierke Disease
Pompe Disease
McArdle Disease
Cornstarch between meals
Nighttime glucose infusions
Von-Gierke disease (GSD type 1)
Cardiomegaly, hypotonia, cardiomyopathy, respiratory distress, recurrent respiratory infections, enlarged tongue
Pompe - infantile type
Sucrose supplementation before exercise
Vitamin B6 supplementation
High protein/fat diet
McArdle Disease (GSD V)
Myoglobinuria, myopathy, skeletal muscle weakness, exercise intolerance, rhabdomyolysis
McArdle disease (GSD V)
Hypoglycemia, hyperlipidemia, Hyperuricemia, lactic acidosis, liver dysfunction/hepatomegaly, DD, seizures, GI problems, growth retardation, renal problems/kidney stones
Von gierke (GSD 1)
X-Linked LSDs
Fabry
Danon disease
Hunter syndrome (MPS II)
Neurodegeneration Vision problems Seizures Personality and behavioral changes Echolalia Clumsiness Poor growth Poor circulation to lower extremities Decreased body mass Breath holding spells Bruxism Neuro degeneration leading to death between 6 yrs and teenage years
Batten disease (LSD)
Hypertrophic cardiomyopathy Wolff Parkinson White conduction abnormality Skeletal muscle myopathy Visual/retinal pigment disturbances ID (usually absent in females)
Danon disease (LSD - X-linked dominant) gene - LAMP2
Pain and tingling in limbs, pain crises, angiokeratomas, anhidrosis/hypohidrosis, corneal whorl, left ventricular hypertophy, GI problems, renal insufficiency (protein urea), depression secondary to chronic pain
Fabry disease (X-linked)
Corneal whorls
Fabry
Erlenmeyer flask deformity
Gaucher disease
Splenomegaly, thrombocytopenia, pulmonary hypertension, bone crises, Erlenmeyer flask deformity, no cns involvement
Gaucher type 1
Bulbar and pyramidal signs, ID, convulsions, hypertonic, apnea, no bone disease/crises, hepatosplenomegaly, thrombocytopenia, pulmonary hypertension, dermatological abnormalities
Gaucher type 2 (most severe)
Lifespan: 2-4 years
Progressive myoclonus epilepsy, oculomotor apraxia, hepatosplenomegaly, thrombocytopenia,
Pulmonary hypertension, bone crises, Erlenmeyer flask deformities, chronic neuropathies
Gaucher type 3
What type of gaucher is ERT not effective for?
Type 2
Irritability, fevers, stiffening of limbs, seizures, feeding difficulties/vomiting, mental and motor delay, muscle weakness, spasticity, deafness, optic atrophy and blindness, paralysis
Krabbe - death by age 2 :(
DD, ID, regression, hepatosplenomegaly, skeletal anomalies, short stature, cardiac anomalies, corneal clouding, hearing loss
Hurler-scheie (MPS I)
DD, ID, regression, skeletal anomalies, short stature, cardiac anomalies, clear corneas, hearing loss
Hunter syndrome (MPS II - X-linked)
Milder skeletal phenotype, coarse facies, progressive sleep and behavior problems, no cardiac anomalies, clear corneas
San-Filippo Syndrome (MPS III)
Severe skeletal phenotype (short trunked dwarfism), normal intellect, chest deformities, cardiac anomalies, bone malformation, macrocephaly
Mosquito syndrome (MPS IV)
Skeletal anomalies, short stature, cardiac anomalies, corneal clouding, normal intellect
Maroteaux-Lamy (MPS VI)
DD, regression, cardiac anomalies, hepatosplenomegaly, recurrent ENT problems
Sly syndrome (MPS VII)
Mildest type of Niemann Pick
Type B
Hepatosplenomegaly Failure to thrive Progressive nervous system deterioration Profound brain damage Development stops at 1 year and regresses Pulmonary insufficiency Recurrent lung infections Cherry red spot Death by 3 years
Niemann pick type A
Form of Niemann Pick where cognitive function may be spared
Type B
Hepatosplenomegaly Dystonia Dysphasia Progressive neurological deterioration Cerebellum ataxia Dysarthria Vertical supranuclear gaze palsy Psychosis Progressive HL
Niemann pick type C
Hyperammonemia
Urea cycle disorders
Severe acidosis
Organic acidemias
Lethargy and seizures
MSUD
Jaundice, hypoglycemia, liver failure
Galactosemias
Hypoglycemia, weakness, cardiac
FAOD
Hypoglycemia, circulatory collapse
CAH
Transient Hyperammonemia is associated with _
Asphyxia (low APGARs)
Rapid and shallow breathing
Hyperammonemia
Deep breathing
Acidosis
Propionic, methylmalonic, isovaleric
Organic acidemias
Primary lactic acidosis
Mito (ETC) defects
Pyruvate dehydrogenase deficiency
Hyperpnea - rapid breathing
Urea cycle defects
Kussmaul - deep breathing
Organic acidemias
Respiratory depression
MSUD
Hiccuping and apnea
Nonketotic hyperglycinemia
Hypoglycemia in newborns differential
Normal CAH FAOD Galactosemias Propionic acidemia Gluconeogenic defects
Hepatomegaly in newborn
Galactosemias
Tyrosinemia (usually later)
FAOD
LSD (usually later)
Seizures in newborn
Nonketotic hyperglycinemia Urea cycle defects (Hyperammonemia) Organic acidemias (Hyperammonemia, hypoglycemia) Gluconeogenic defects (hypoglycemia) LSDs (usually later)
Amino acids disorders
Urea cycle, organic acidemias, MSUD, nonketotic hyperglycinemia
Carbohydrate disorders
Galactosemias, gluconeogenic defects, electron transport chain defects
Female heterozygote may be protein intolerant
OTC
Vomiting, hyperpnea, lethargy
Organic acidemias
Vitamin B12 enzyme
Methylmalonic acidemia
Elevated C3 acylcarnitine
Methylmalonic acidemia
Sweaty feet
Isovaleric acidemia
Riboflavin (vitamin B2)
Isovaleric acidemia
Elevated C5 acylcarnitine
Isovaleric acidemia
Branched chain ketoacid dehydrogenase
MSUD
Elevated leucine in NBS
MSUD
Lethargy, hypotonia, respiratory depression, seizures.
Progresses to vomiting, ketoacidosis
MSUD
Liver failure, E. Coli sepsis
Galactosemia
Jaundice, hepatomegaly, vomiting
Galactosemia
Improve on IV fluids and then get worse when fed
Galactosemia
Fasting hypoglycemia, liver disease, myopathy
FAOD
C8 acylcarnitine
MCAD
C14:1 acylcarnitine
VLCAD
Long chain defects can cause
Progressive liver/muscle disease
Prenatal virilization in females
CAH and antley bixler
Salt wasting
21-OH deficiency
Defects in what also cause elevated phenylalanine?
tetrahydrobiopterin (BH4 needed in other reactions and does not respond to PKU diet alone)
Teratogen that causes microcephaly and heart malformations
Maternal PKU
What does Galactose-I-phosphate do?
Converts galactose (in milk) to glucose (blood sugar)
Feeding intolerant, vomiting, liver failure (jaundice liver enlargement, blood clotting abnormalities), predisposition to infections
Galactosemia
Resolves when milk is removed from the diet
Galactosemia
Duarte variant
N314D - common variant sometimes picked up by galactosemia screening (low activity, 5% population frequency, does not require treatment)
False positives in summer
NBS that tests for enzyme levels of galactosemias (GalPUT, GALT)
Hypoglycemia, coma, “SIDS”
MCAD
A985G
Common MCAD mutation (>90% of Caucasian MCAD mutations)
Hexanoylglycine
MCAD - Acylglycine analysis
Most frequent condition in NBS
Hypothyroidism (1/3000)
Lethargy, sleepiness, poor feeding and growth, hoarse cry, DD
Hypothyroidism (treated with oral thyroid hormone replacement)
Start T4 replacement as soon as possible
Hypothyroidism NBS
Poor feeding, lethargy, virilization of females, salt wasting
Congenital Adrenal Hyperplasia (CAH)
Cortisol and Florinef (mineralocorticoid) + NaCl = treatment
CAH
Methionine increased on PAA
homocystinuria
Citrulline increased on PAA
Urea cycle disorders
Leucine increased on PAA
MSUD
Fasting or feeding specimens for PAA?
Fasting preferred
C3 on Acylcarnitine
Propionylcarnitine (propionic or methylmalonic acidemia)
B12 defects
Methylmalonic aciduria and homocystinuria
Skeletal dysplasia, joint stiffness, organomegaly, intellectual deterioration, excretion of “glycosaminoglycans” in urine
General features of MPS
Glycosaminoglycans
Mucopolysaccharides (other name)
Acute acidosis in neonatal period
Methylmalonyl-CoA mutase deficiency or Propionic acidemia
Defect in methionine metabolism
Homocystinuria
Folate defect
Homocystinuria - associated with thrombosis and neural tube defects
Multiple carboxylase deficiency
Biotin defects
_ granules in liver cells
Glycogen
_ cells in bone marrow
“Gaucher”
Categories of Lysosomal Storage Diseases
Glycolipidoses, Mucopolysaccharidoses, Oligosaccharidoses
Glycolipidoses
Gangliosides, cerebrosides, etc.
Gaucher, Niemann-Pick, Tay-Sachs, Krabbe, Fabry, etc.
MPS
Glycosaminoglycans
Oligosaccharidoses
Glycoproteins
Similar to MPS
Sphingolipids
Think LSDs
Glycogen accumulation in tissues
Liver, Heart, Skeletal muscle (Glycogen Storage Diseases)
Fasting hypoglycemia
Glycogen Storage Diseases
Muscle weakness, pain on exercise
Glycogen Storage Diseases
Enlarged spleen, anemia, low platelet count (thrombocytopenia), Interstitial lung disease, Bony involvement (pathologic fractures)
Gaucher Disease - “Erlenmeyer Flask” on X-ray
Low platelet count
thrombocytopenia
N370S
Common AJ mutation in Gaucher type I
L444P
Common Swedish mutation in Type 3 Gaucher
Neuronopathic type of Gaucher
Type 3, slowly progressive neurologic disease
Distubance of upward gaze
Common mutation in Swedish population
Sphingomyelinase deficiency
Causes Types A and B of Niemann Pick
Cholesterol trafficking defect
Niemann-Pick type C
Hepatosplenomegaly, hypotonia, neurologic deterioration, poor growth
Niemann-Pick Disease
Palsy of upward gaze
Type C Niemann-Pick
Dysostosis multiplex on X-ray
MPS (and other LSD’s)
Hepatosplenomegaly, corneal clouding, bony involvement - dysostosis multiplex, +/- progressive neurologic impairment, obstructive/restrictive pulmonary disease, cardiac valve dysfunction, hearing loss
MPS in general
Defects in glycogen breakdown lead to
fasting hypoglycemia
“fast twitch” muscles use
glucose as preferred energy source
Defects in glycogen breakdown lead to energy deficit
Weakness, pain, cramping, muscle breakdown after exercise
Hepatosplenomegaly, FTT, progressive cirrhosis, liver failure, myopathy/cardiomyopathy
GSD IV
Spectrum of severity for GSDs
GSD1 is most severe, GSD VI is least severe
Leukodystrophy
Brain white matter changes on MRI
CK or CPK
Muscle enzyme, elevation indication of muscle breakdown