High Yield biochem level 1

what is this? association?

confusion, ataxia, nystagmus, alcoholism

Wernicke encephalopathy → thiamine (B1) deficiency

what is this? association?

confabulation: when people forget certain periods of time and fill in the gaps with details that did not actually happen

Korsakoff syndrome → thiamine (B1) deficiency

what anatomical structures of the brain are affected by thiamine deficiency due to Wernicke-Korsakoff syndrome?

medial dorsal nucleus of thalamus and mammillary bodies

what is this? association?

pt presents with dermatitis (casal necklace), diarrhea, and dementia

Pellagra → niacin (B3) deficiency

what is this?

lack the transporters in the PCT and cannot reabsorb tryptophan

Hartnup disease → leads to niacin (B3) deficiency (tryptophan needed to make niacin)

niacin (B3) is needed for what?

NAD+ and NADP+

what role does folate play in embryogenesis?

closure of neural tube → can cause neural tube defects in baby if deficient

lab difference for folate (B9) vs cobalamin B12 deficiency

folate: increased homocysteine

B12: increased homocysteine and methylmalonic acid

where is folate absorbed in the gut?

jejunum

where is cobalamin (B12) absorbed in the gut?

terminal ileum

what is this?

collagen production affected, bleeding in joint spaces, easy bleeding, corkscrew hairs, “tea and toast” diet

scurvy → vitamin C deficiency

what is this?

night blindness, dry skin, and bitot spots (pictured)

vitamin A (retinol) deficiency

what vitamin and cancer go together and how?

acute promyelocytic leukemia (APML) → can be treated with all-trans retinoic acid

what vitamin is needed to make NAD+ and NADP+?

niacin (B3)

what is this? enzyme deficiency?

you see fructose in the urine (other than this its generally asymptomatic)

fructokinase deficiency → fructosuria

what is this? enzyme deficiency?

if a child presents with hypoglycemia, jaundice, and vomiting after eating fruit or something sweet

aldolase B deficiency → hereditary fructose intolerance

note: treat with diet mod (stay away from fructose, sucrose, etc.)

with hereditary fructose inheritance, what do we see in the cells? what enzyme deficiency?

increase of fructose-1-phosphate in cells

aldolase B deficiency

what is this?

pt presents with cataracts in eyes, inability to track objects, and lack of a social smile

galactokinase deficiency

what is this? enzyme deficiency?

infant who is breast feeding and then presents with cataracts, enlarged liver, jaundice, and failure to thrive

galactose-1-phosphate uridyltransferase deficiency → classic galactosemia

underlying condition?

breast feeding baby with E coli sepsis

galactosemia → increased galactose basically feeds the E coli and contributes to its growth in the baby

note: treatment is diet mod

What is this? enzyme deficiency?

present with gout, fasting hypoglycemia, increased glycogen in kidneys and liver

labs show: elevated urate levels, elevated triglycerides, and elevated blood lactate levels

Von Gierke disease; glucose-6-phosphatase deficiency (G6P NOT G6PD)

what is this? enzyme deficiency?

pt has heart issues young (cardiomyopathy and can’t tolerate exercise) and generalized hypotonia of the muscles and difficulty breathing

Pompe disease → alpha-1,4- glucosidase deficiency

what is this? enzyme deficiency?

normal blood lactate levels, mild hypoglycemia

Cori disease → debranching enzymes deficiency

what is this? enzyme deficiency?

elevated creatinine kinase, muscle cramping and myoglobinuria during physical activity; can also see exhaustion after exercise and then get a second wind

McArdle disease → glycogen phosphorylase of skeletal muscle deficiency

what is this? enzyme deficiency?

recurrent viral, bacterial, and fungal infections; low B and T cells, low immunoglobulins (IgG, IgM, etc)

SCID (severe combined immunodeficiency) → deficiency of adenosine deaminase

what is this? enzyme deficiency?

intellectual disability and self mutilation

Lesch-Nyhan syndrome

HGPRT deficiency

what is this? pathophys?

soft tissue tumors, osteosarcoma, adrenocortical carcinomas, and leukemias

Li-Fraumeni syndrome → P53 gene mutation

what is this? enzyme deficiency?

corneal clouding, gingival hyperplasia, and coarse facial features

I-cell disease

what is this?

night blindness and scaly dry skin

vitamin A deficiency (eyes and skin affected)

what is this?

confusion, ophthalmoplegia, nystagmus, and gait ataxia

Wernicke → thiamine (B1) deficiency

how to treat Wernicke Korsakoff?

replace/give thiamine then glucose

what is this?

fissures at corner of mouth and red tongue

riboflavin (B2) deficiency

what is this?

peripheral neuropathy after being treated for a disease that causes fever, night sweats, and hemoptysis

pyridoxine (B6) deficiency → isoniazid treatment for TB can lead to B6 deficiency

what is this?

cystic fibrosis pt with bleeding issue; high PT and PTT

vitamin K deficiency (can also be seen with a baby that is born at home)

what is this?

pt with a lack of taste/smell and perioral/perianal rash

Zinc deficiency

what is this?

vomiting after breastfeeding, cataracts, reducing substances in urine

galactosemia

what is this?

watery diarrhea, positive hydrogen breath test, decreased stool pH, and increased stool osmolality

lactose intolerance

what is this? deficiency?

musty body odor and intellectual disability

phenylketonuria → deficiency of phenylalanine hydroxylase

what is this? deficiency?

hepatosplenomegaly and cherry red macula

Niemann-pick disease → sphenogomylinase deficiency

what is this?

cherry red macula and no hepatosplenomegaly

Tay-Sachs disease

what is this? deficiency?

bone pain, hepatosplenomegaly, and pancytopenia

Gaucher disease → glucose cerebrosidase deficiency

what is this?

fatty stools, night blindness, and lipid laden enterocytes

abetalipoproteinemia

what is this?

high triglycerides and creamy layer in blood

hyperchylomicronemia

what is this?

accelerated atherosclerosis, family history of early MI, mutation of LDL receptors in the liver

familial hypercholesterolemia

what is this?

recurrent infections, infertility, apex of the heart on the right

primary ciliary dyskinesia (Kartagener)

what is this? pathophys?

recurrent fractures, blue sclera, and teeth and hearing issues

osteogenesis imperfecta → type I collagen defect

what is this? pathophys?

pt with short limbs but normal sized head

achondroplasia → gain of function of FGFR3

what is this?

pt with brittle kinky hair and low copper

Menkes disease

what is this? pathophys?

pt with stretchy skin, easy bruising, and hyperextensible joints

Ehlers Danlos syndrome → collagen mutation

what is this? pathophys? midsystolic click?

tall long arms and legs, upward lens dislocation, midsystolic click

Marfan syndrome → fibrillin gene mutation and mitral valve prolapse

what is this?

tearing chest pain, cystic medial necrosis of the aorta, associated with Marfan syndrome

aortic dissection

what is this?

downward lens dislocation, recurrent DVT, and intellectual disability

homocystinuria

what is this? mutation and channel affected?

recurrent infections, poor growth, fatty stools, nasal polyps, pseudomonas infections

Cystic fibrosis → CFTR mutation and abnormal chloride channels

what is this?

delayed passage of meconium withing 1st 48 hours and bilious vomiting

meconium ileus (can have underlying CF)

what is this?

epigastric pain radiating to the back, complication of CF

pancreatitis

what is this? explain how to get this

obese child, loves to eat, temper tantrums, almond shaped eyes

Prader Willi syndrome → paternal deletion of chromosome 15 or uniparental disomy of maternal chromosome 15

what is this? explain how to get this

little happy girl with inappropriate laughter

Angelman syndrome → maternal deletion of chromosome 15 or uniparental disomy of paternal chromosome 15

what is this?

bony outgrowths of the face, hyperpigmented spots on skin (cafe au lait spots), precocious puberty

McCune Albright syndrome

what is this?

boy with muscle weakness, uses arms to help stand up, bilateral calf enlargements, high CK

Duchenne/ Becker muscular dystrophy

Duchenne worse than becker

what is this?

S3, decreased EF, eccentric hypertrophy, globally enlarged heart

dilated cardiomyopathy

what is this?

delayed release of handshake or difficulty releasing doorknobs, etc., balding, testicular atrophy

myotonic dystrophy

what is this? pathophys?

boy with big face, big jaw, big ears, and big testes

Fragile X syndrome → trinucleotide repeat of CGG (GG for giant gonads)

what is this?

slanted palpebral fissures, single palmar crease, epicanthal folds, and duodenal atresia

down syndrome (trisomy 21)

what is this?

cutis aplasia (absence of epidermis over skull), holoprosencephaly, omphalocele

Patau syndrome (trisomy 13)

what is this?

closed fist with overlapping fingers and micrognathia (small jaw)

Edwards syndrome (trisomy 18)

what do we see with the organs of a pt with Turner syndrome?

coarctation of aorta and horseshoe kidney

What is this? deficiency?

baby presenting with seizure, weak cry, difficulty feeding, vomiting, and elevated levels of propionic and odd-chain fatty acids, decreased MMA

propionic acidemia → deficiency of propionyl-CaO carboxylase

what is this? what do we suspect with ABG?

pt presents with confusion, weakness, vertigo, and headache after exposure to a house fire; hypoxemia that is not responsive to oxygen

cyanide poisoning (always suspect if house fire) → issue with cytochrome C oxidase → metabolic acidosis with an anion-gap

what is this? how to treat?

child presents with lethargy, seizures, has ketoaciduria, and a deficiency of alpha-keto acid dehydrogenase

maple syrup urine disease → dietary restriction of leucine, isoleucine, and valine

what is this? what do we see?

child presents with failure to thrive, poor feeding, lethargy, jaundice, enlarged liver, and positive urine-reducing substances

classic galactosemia → increased galactose-1-phosphate

if we have folate deficiency, a defect in what mechanism characterizes this diagnosis? what about coabalmin/B12 deficiency?

both: transfer of methyl groups/ methylation defect

what is this?

pt presents with hyperammonemia, elevated orotic acid levels, vomiting, poor growth, and cognitive impairment

ornithine transcarbamoylase deficiency

what is this? defect?

pt presents with large tongue, enlarged liver, heart murmur, crackles in lungs, hypotonia

Pompe disease → alpha-1,4-glucosidaase deficiency

if a pt has megaloblastic anemia (neutrophils with 6-7 nuclear lobes on peripheral smear) → either B12 or B9 deficiency. why then do es the pt have impaired erythrocyte maturation?

impaired conversion of deoxyuridylate to deoxythymidylate (B9 and 12 are cofactors needed for this conversion)

what is this?

pt with downward lens dislocation, scoliosis, tall stature, and developmental/learning difficulties

homocystinuria→ see increased homocysteine levels in urine

note: Marfan and homocystinuria present similarly, but if they are saying the pt has developmental delay or asking about urine substances, then think homo not marfan

how do elevated glucose levels affect the retina?

1. accumulation of sorbitol within the nerves

2. nonenzymatic glycation of proteins

what is this? what is the defect? deficiency?

pt with coarse facial features, corneal clouding, enlarged liver

I-cell disease → defect in protein tagging at the golgi apparatus → deficiency in N-acetylglucosaminyl-1-phosphotransferase

familial hypercholesterolemia is characterized by either ___ or ____

abnormal LDL cholesterol receptors or abnormal apolipoprotein B-100

what are the diseases that are associated with trinucleotide repeats? what trinucleotide repeat goes with each?

Huntington’s disease → CAG

Fragile X syndrome → CGG

Friedreich’s ataxia → GAA

Myotonic dystrophy (Type 1) → CTG

what is this?

pt with aggression, psychosis, chorea, and dementia

Huntington’s disease → CAG

what disease?

increased dopamine and decreased ACh, GABA, and caudate

Huntington’s disease → CAG

what is the mnemonic for Huntington’s disease?

Can’t Aim Great when you HUNT 4 an animal

CAG

HUNTington’s disease

chromosome 4

AN-ticipation

in subsequent generations the next generation will develop the disease earlier than the generation before. what is this and what disease does it go with?

genetic anticipation → huntington’s disease

what is this?

pt presents with long face, long ears, intellectual disability, and macroorchidism (large testes)

Fragile X syndrome → CGG (congenitally giant gonads)

what is this?

ataxia or staggering gait, hammertoes, pes cavus, and scoliosis

Friedreich’s ataxia → GAA

with Friedreich’s ataxia, what is the most common cause of death?

hypertrophic cardiomyopathy

what is this?

mitochondrial dysfunction due to iron accumulation → mitochondria then cannot produce energy for the cells → CNS and PNS dysfunction

Friedreich’s ataxia → defect in frataxin gene

what is this?

distal extremity weakness, cataracts, testicular atrophy, and gammaglobulinemia

myotonic dystrophy → CTG

What is this?

pt can’t release grip when opening door, can’t release grip with handshake, or when turining a screwdriver

Myotonic dystrophy → CTG

what is the mnemonic for myotonic dystrophy?

CTG = cant terminate grip (bc this is what you see) and also CTG for cataracts, testicular atrophy, and (hypo)gammaglobulinemia

what are the trinucleotide repeat diseases and inheritance patterns?

Huntington’s → CAG → autosomal dominant

Fragile X → CGG → X-linked dominant

Friedreich’s ataxia → GAA → autosomal recessive

Myotonic dystrophy → CTG → autosomal dominant