Metabolic Disorders Flashcards
Methylmalonic Acidemia
- Inheritance
- Causes (2 main types)
- Result = ____
- Symptoms (10)
- Treatment (3)
- Autosomal Recessive
- Causes
- Defect in enzymes along the propionic acid pathway
- methylmalonate CoA mutase
- methylmalonate CoA epirimase
- enzymes required to synthesize adenosylcobalamin
- (acquired) vitamin B12 deficiency
- Defect in enzymes along the propionic acid pathway
- Cannot break down:
- Valine
- isoleucine
- threaonine
- methionine
- Odd chain fatty acids
- Symptoms
- feeding problems, hypotonia, lethargy / coma
- Severe anion gap metabolic acidosis
- ketosis
- hyperammonemia
- hypoglycemia
- electrolyte / fluid abnormalities
- hematologic abnormalities
- liver / renal dysfunction
- Developmental delay / ID
- Extrapyramidal movement disorder (due to BG damage)
- Treatment
- Metronidazole
- low protein diet
- supplementation with carnitine and AA mixtures not containing the ones they can’t metabolyze
Biotinidase Deficiency
- Inheritance
- Function of deficient enzyme
- Symptoms (8)
- Lab evaluation (3)
- Inheritance: autosomal recessive
- Symptoms
- Seizures
- hypotonia
- ataxia
- developmental delay
- hearing / visual loss
- spastic paraparesis
- cutaneous abnormalities
- alopecia
- Lab evaulation
- ketaocidosis
- hyperammonemia
- organic aciduria
Arginosuccinate lyase deficiency
- inheritance
- symptoms (7)
- Lab findings (4)
- Inheritance: autosomal recessive
- Symptoms
- Vomiting
- lethargy
- hypotonia
- seizures
- coma
- respiratory failure
- trichorrhexis nodosa: brittle hair with nodules along the shaft
- Lab findings
- elevated serum citrulline
- elevated serum argininosuccinic acid
- Decreased serum artginine
- elevate urine orototic acid
Galactosemia
- Inheritance
- Defective Enzyme
- Symptoms (8)
- Treatment
- Autosomal Recessive
- Galactose-1-phosphate uridyl transferase
- Symptoms
- Infantile onset
- Enlarged liver
- cataracts
- gram-negative sepsis
- Poor weight gain
- ovarian failure
- developmental delay
- speech disorders
- Treatment
- Diet free of galactose
X-linked Adrenal leukodystrophy
- Inheritance
- Defective enzyme and result
- MRI features
- X-linked recessive
- Mutation in ABCD1 (ALD) gene > peroxisomal protein involved in VLCFA degradation >
- inflammatory demyelination (occpital / parietal first, spares arcuate fibers)
Various clinical phenotypes of Adrenal leukodystrophy
- Childhood-onset(7)
- Adolescent onset (2)
- Adult onset (5)
- Adrenomyeloneuropathy (6)
- Addison’s only (1)
- Heterozygous females (3)
- Childhood onset (2.5-10 years)
- Bronze-skinned kid with ADHD-like features, then develops problems with speech and handwriting
- Subsequently develops spacial disordientation, seizures, and spastic quadriparesis
- Adolescent onset (10-21)
- Similar to childhood, but presents later
- Endocrine dysfunction
- Adult onset adrenoleukodystrophy
- rapidly progressive dementia
- psychiatric changes (psychosis, schizoaffective)
- CNS demyelination
- Endocrine dysfunction
- possible myelopathy or neuropathy
- Adrenomyeloneuropathy (early adulthood)
- Rapidly progressive spastic paraparesis
- bowel / bladder incontinence
- sexual dysfunction
- mild dementia
- psychiatric changes
- Sensorimotor, primarily axonal neuropathy
- Addison’s only
- Isolated adrenal dysfunction
- Heterozygous females (develop by age 60)
- Peripheral neuropathy
- fecal incontinence
- pain in legs
Gaucher’s disease
- Epidemiology Note
- Inheritance
- Defective enzyme
- Symptoms
- Type 1 (5)
- Type 2 (7)
- type 3
- Treatment
- Most prevalent genetic disorder among Ashkenazi Jews (account for ⅔ of all cases)
- Inheritance = autosomal recessive
- Defectvie Enzyme: b-glucocerebrosidase
- Symptoms
- Type 1 (most common, doesn’t invade CNS)
- HSM
- Anemia
- Thrombocytopenia
- Skeletal abnormalities (osteopenia / osteonecrosis)
- Pulmonary infiltrates
- Type 2 (onset befor age 2, death by 2-4)
- HSM
- Hydrops fetalis
- Cutaneous changes
- Psychomotor involvement
- Spasticity
- Coreoathetosis
- Occulomotor abnormalities
- Type 3 (onset after 2, slow progression)
- HSM
- Psychomotor retardation
- spasticity
- Occulomotor abnormalities
- Type 1 (most common, doesn’t invade CNS)
- Treatment: enzyme replacement therapy
Krabbe’s Disease
- AKA
- Inheritance
- Defect
- Most common age of onset
- Presentation
- AKA Globoid cell leukodystrophy
- autosomal recessive
- galactosylceramide beta-galactosidase
- onset: typically in infancy
- Presentation, 10 Ups, and 7 downs
- UPS
- temperature
- babinski
- Movements (opisthotonus)
- CSF protein
- Signal in
- Basal Ganglia
- Thalamus
- Corona radiate
- brainstem
- cerebellum
- Globoid cells
- DOWNS
- DTRs (other than babinski)
- appetite
- sight
- hearing
- Cognition
- Myelin in nerves (demyelination)
- nerve conduction velocities
- UPS
Maple Syrup Urine Disease
- Gene
- Inheritance
- Symptoms
- Treatment
- Subtypes (4)
- one of four genes part of : defect in branched-chain keto acid dehydrogenase complex
- Inheritance: Autosomal Recessive
- Dark urine (made by blood and high levels of branched-chain amino acids and ketoacids)
- Treatment: protein restricted diet
- Subtypes
- Intermidiate (not as bad, some enzymes)
- Thiamine responsive
- Intermittent
- response to catabolic loads (infection, large protein load)
- urine / cerumen only smells during these episodes.
- Dihydrolipoyl dehydrogenase deficient (only in infancy)
Menke’s Disease
- Inheritance
- Gene mutation and effect
- symptoms (6)
- Lab findings
- X-linked recessive
- ATP7A > deffective copper transporter > widespread copper deficiency in brain and organs
- Symptoms
- Brittle hair (pili torti)
- hyperelastic skin
- thin / absent eyebrows
- cerebral vasculopathy and progressive cerebral atropy > subdrual hematomas / hygromas
- Developmental delay
- Seizures
- Lab findings
- low serum cerulopasmin and copper
McArdle’s Disease:
- AKA (2)
- Inheritance
- defective enzyme
- Symptoms (2)
- Diagnosis (3)
- AKA
- myophosphorylase deficiency
- Glycogen storage disease type V
- Inheritance: autosomal recessive
- Decreased phosphorylase activity exclusively in muscles
- Symptoms
- muscle cramps and myoglobinuria following intense exercise
- absent DTR
- Diagnosis
- lactate does not rise after exercise
- Electrographically silent muscle cramps
- muscle biopsy = glycogen crystals and absent myophosphorylase
- Defective enzyme in:
- Von Girke’s
- Pompeii’s disease
- Cori
- McArdles
- Von Girkes: Glucose-6-Phosphatase (“6 letters in ‘Girke’s’ “ )
- Pompeii = Acid Maltase (acid rain at Pompeii)
- Cori: Debranching enzyme (branches of a Cor-tree)
- Mcardles: Skeletal muscle glycogen phosphorylase
GM1 gangliosidosis
- Inheritance
- mutation and enzyme
- Subtypes (3)
- Symptoms (5)
- Autosomal recessive
- GLB1 gene > beta-galactosidase
- Onset
- Infantile:
- 6-18 months
- Death by age 7
- Infantile:
- Type II:
- Intermediate form
- Type III:
- Adult form (mildest)
- Symptoms
- Hypotonia progressing to spasticity
- Seizures
- cognitive and visual impairment
Fabry’s disease
- Inheritance
- Gene
- Onset
- Symptoms (8)
- X-linked recessive
- Defecient in alpha galactosidase A (AGA) > buildup of globotriaosylceramide (fatty substance)
- Childhood / adolescence
- Symptoms
- Severe limb pain worsened by summer, after exertion, or during periods of stress
- Corneal deposits
- Rest are “A’s”
- Angiokeratosis
- Acroparasthesias
- Autonomic failure with Anhydrosis
- Arrhythmia / Hypertorphic heart failure
- Acute renal failure
- Abdominal Pain
Metachromatic leukodystrophy
- Inheritance
- defective enzyme
- symptoms (3)
- Autosomal recessive
- arylsulfatase A
- Symptoms
- behavioral and cognitive disturbances
- seizures
- periopheral neuropathy


Isovaleric Acidemia
- Inheritance
- Deficiency
- Symptoms (3)
- Treatment (3)
- Inheritance = autosomal recessive
- Deficienty enzyme: isovaleryl-CoA dehydrogenase
- Leads to accumulation of isovaleric acid
- Symptoms
- lethargy / vomiting within first days of life
- Ketoacidosis
- urine smells like sweaty feet
- Treatment
- dietary protein restriciton
- levocarnitine
- glycine supplementation
Propionic Acidemia
- Inheritance
- Defective enzyme
- Symptoms
- Autosomal recessive
- Defect in propionyl-CoA carboxylase
- Symptoms
- Lethargy
- hypotonia
- Seizures
- Dehydration
- Hepatomegaly
- neutropenia
- thrombocytopenia / hemorrhages
- basal ganglia infarctions
- Hyperammonemia
- ketoacidosis
Citrulinemia
- Inheritance
- defficient enzyme
- Leads to accumuation of ___
- Symptoms (5)
- Inheritance = autosomal recessive
- Defective enzyme = argininosuccinate synthetase
- Accumulation of Orotic acid
- Accumulation of Ammonia
- Symptoms
- Vomiting / lethargy / hypotonia
- Hepatomegaly
- Ataxia
Sandhoff disease
- Slightly larger category name
- Inheritance
- deficient enzyme
- Presentation (7)
- GM2 gangliosidosis disorder
- autosomal ressive
- deficiency of both hexosaminidase A and B
- Presentation (3-6 months)
- Increased startle response
- neuro/motor regression
- spasticity
- Optic atrophy/ blindness
- cherry red spot in macula
- Macrocephaly
- Hepatosplenomegaly (how you differentiate from tay-sachs)
2.5 y.o. girl with weakness and muscle weakness a year prior.
normal CK
EMG = neuropathic motor units
exaggerated DTR
atrophy and fasciculations of the tongue
Tay-sachs
hexoseaminidase A
Infant arrives with suspected child abuse due to retinal hemorrhages.
Subsequently found to by dystonic / opisthotonic, and macrocephalic
What MRI findings lead you to call off CPS?
What is the disorder?
what do you warn family of in times of Illness?
MRI findings of Frototemporal atrophy with prominent sylvian fissures (“bat wing” appearance)
Glutaric acidemia type I
encephalopathy, seizures, vomiting, acidosis, hyperammonemima, and ketotic hypoglycemia
“sweaty feet odor”
Think of what three disorders and how to separate them?
Glutaric aciduria type II:
- Hepatomegaly
- typically in
Propionic Acidemia
- elevated propionic acid
- Mention unable to break down “VOMIT”
- Valine
- odd chain fatty acids
- methionine
- Isoleucine
- Threonine
- …also cholesterol
Isovaleric acidemia
- Will be hard to differentiate PA from IA without mentioning propionic acid
What two metabolic conditions do you want to rule out if you see an infant with retinal hemorrhages
Glutaric aciduria type I
Menkes
(dyslexia trip-up)
HARP syndrome versus Hartnup disease
HARP = sometimes due to PANK2 gene
- Hypobetalipoproteinemia
- Acanthosis
- Retinitis pigmentosa
- Psllifsl frhrnrtsyion
Hartnup disease = Aminoacidopathy due to transport of neutral amino acids across kidney / intestine
- H - hypotonia (not always), H - hat needed (due to photosensitvity from biotin deficiency)
- A - ataxia, A - aminoaciduria, A - altered mental status
- R - Rash (due to photosensitivity)
- T - tryptophan = deficient
- N - Nicotinamide is needed
- U - urine and
- P - Poop have elevated neutral amino acids
“smelly baby”
“sweaty feet”
“musty / mousy”
“maple syrup”
Sweaty feet
- Glutaric aciduria type II
- isovalaric acidemia
- propionic acidemia
Musty / mousy
- phenylketonuria
Maple syrup
- MSUD
All mucopolysaccharidoses are due to an inability to do what?
Break down glycosaminoglycans (GAGs) in lysosomes
zebra bodies
Mucopolysaccharidoses
Abetalipoproteinemia
AKA:
inheritance
Deficiency
Symptoms
AKA: Bassen-Kornsweig syndrome
inheritance: Autosomal Recessive
defect: MTP transporter protein (“more toilet paper” for my stetorrhea)
symptoms: B.A.S.S.E.N.
- B-apolipoprotein is deficient
- A - acanthosis (on peripheral smear), Ataxia, Arreflexia, vitamins (A),D,E,K are deficient (due to steatorrhea)
- S - teatorrhea
- S - ensory loss (proprioception / vibratory), (S)pinocerebellar degeneration
- E - ye findings (pigmentary retinopathy)
- N - europathy
Acute-intermittent porpheria, but also has a rash
What do you think of?
Variagate Porphyria
Peroxisomal disorders (3)
Lysosomal disorders (3)
Peroxisomal disorders
- Neonatal Adrenal leukodystrophy
- Infantile refsum disease
- Zellweger disease
Lysosomal disorders
- Mucopolysaccharidoses
- Neuronal Ceroid Lipofuscinoses
- Sphingolipidoses
Adrenal-leukodystrophy
Diagnostic test results (3)
- Increased Very long chain fatty acids
- lamillar cytoplasmic inclusions in brain / adrenal macrophages
- demyelination (leukodystrophy), typically occiput is first
Bronze-skinned child with ADHD and cognitive decline
What Labs (3) would you order to confirm this kid doesn’t have?
(rule out Adrenalleukodystrophy)
MRI: occipitut-first demyelination
Labs: Increased VLCFA
Histology: Lamellar cytoplasmic inclusions in brain / adrenal macrophages
Young man comes in with schizophrenia-like episodes, but also dementia and spasticity.
What do you test for?
Serum VLCFA (for adult-cerebral form of Adrenaleukodystrophy)
Aromatic L-amino-Decarboxylase Deficiency
AKA
Onset
symptoms (5)
Diagnostic test
AKA: AADC deficiency
Onset: first fiew months
Symptoms: AA(AA)DC
- (A)utonomic dysfunction (hypothermia, problems with sweating
- (A)taxia, (A)thetosis
- (A)xial HypOtonoia but limb HypERtonia
- (D)ystonia / torticollis
- C(SEE) - Ptosis, oculogyric crisis
Diagnosis
- CSF neurotransmitters
Disorders involving inreased Very long chain aminoa cids (VLCFA)
“Raz the weak, sickly dog”
R - efsum disease (infantile only), Rhizomelic chondroplasia punctata)
A - Adrenal leukodystrophy
Z - Zellweger syndrome
Dopamine beta-hydroxylase deficiency
Inheritance
Symptoms (3)
Treatment (1)
what disease does this treatment NOT work for and why?
Can’t convert Dopamine to Norepenepherine
Inheritance: AR
Symptoms (remember beta-HYdroxylase)
- HypOthermia
- HypOglycemia
- HypOtension
Treatment:
- L-DOPS (DL-Threo-dihydroxyphenylserine)
- Doesn’t work on AADC deficiency because you need AADC to convert it to Norepi

Alexander’s Disease
George in ‘seinfield’ is played by Jason Alexander
- Defect in GFAP
- Autosomal Dominant
- Megalencephaly
- Seizures
- Spastic Quadriparesis
- Manifests in Infancy (he looks kinda like a baby)
- Death in a few years (how long Seinfeld should have lasted)
- MRI shows Frontal balding (like Jason Alexander)
Classic refsum disease
Inheritance
Defective enzyme
Accumulated Protein
Symptoms (9)
treatment
Inheritance: autosomal recessive
enzyme: phytanoyl-CoA hydroxylase > increased phytanic acid
Symptoms, remember “REFSUM”
- Rough skin (ichthiosis), Retinitis pigmentosa
- Ears (deafness, Eyes (night-blindness)
- Falls and Fytanic acid elevation
- Smell (anosmia)
- Unsteady gait (ataxia)
- Myelin is lost (demyelinating neuropathy with onion-bulbs)
Treat with restriction of phytanic acid
Infantile Refsum disease
Inheritance
Features in common with classic Refsum (4)
Features different than classic Refsum (2)
Inheritance - autosomal recessive
Features in common with classic Refsum
- demyelinating neuropathy (like classic refsum)
- Retinitis pigmentosa (like classic refsum)
- Deafness (like classic refsum)
- Elevated Phytanic acid
Features that are different
- Steatorrhea
- elevated VLCFA
Down-syndrome feature which is also associated with Severe metabolic disorder
Brushfield spots (also seen in Zellweger syndrome)
Zellweger syndrome
inheritance
symptoms
Inheritance = autosomal recessive
Symptoms
- Characteristic appearance
- prominent forehead
- prominent epicanthal folds
- Cataracts
- Brushfield spots (seen in down syndrome)
- Neuronal migration defects (PMG, heterotopia, pachygyria)
- demyelinating neuropathy
- HSM
- Renal cysts
Labs
- Increased VLCFA

Metabolic disorders which target the U-fibers on MRI
Alexanders
Canavans
Canavan disease
::flailing arms:: “U didn’t see the spartan CaNAAvan, carrying Big, wet Sponges”
- Defect of aspartoacylase,
- Macrocephaly (big), but with spongy degeneration (mri shows involvement of U-fibers)
- Seizures
- Spasticity and opisthotonus (flailing)
- Optic atrophy
- elevated N-acetyl-L-aspartic acid (NAA) in:
- Serum
- Urine
- MR-spectroscopy
Carbohydrate-Dependent Glycoprotein syndromes
- When should you consider this disease?
- defect
- Symptoms
(type 1)
- Consider in a patient with seizure or developmental delay with coagulopathy
- Defect in phosphomannomutase (sounds like a spell in harry potter that would cause this)
- Reverse the spell with ATKINS
- Ataxia, Abnormal fat distribution (lipodystrophy above buttocks and suprapubic region)
- Transferrin = deficient carbohydrate, Tone is low
- Koagulopathy
- Inverted
- Nipples (and Nystagmus)
- Seizures, Stroke-like episodes, Strabismus
- “if you have fat above the bum, think CDG-1”
Cerebral folate deficiency
Symptoms
Treatment
Remeber (3, 4, 5, 6, 7)
- “at 3 years she lost her vision”
- “but symptoms started at 4 months with”
- (5 symptoms)
- Seizures
- Microcephaly
- Spastic paraplegia
- Cerebellar ataxia
- Dyskinesia
- “They found elevated 5-methyltetrohydrofolate in her CSF”
- By age 6, she couldn’t hear us”
- Treatment = folinic (7 letters) acid (leukovorin)
Glut-1
Onset
Symptoms
treatment
AKA DeVivo disease
Onset at four months (“quatro”)
Symptoms
- Low CSF glucose, but normal lactate
- abnormal eye movements resembling opsoclonus
- Microcephaly
- Apnea
Treatment: Ketogenic diet
“De Vivo, low-gluco, opso, micro, treat with keto, pronto (because of apnea)!”
Galactosemia
Inheritance
Defective enzyme
Onset
symptoms (6)
- AR
- Multiple enzymes, but MC (classic) is Galactose-1-phosphate uridyl transferase
- onset: hypotonic neonate
- other symptoms
- hepatomegaly
- jaundice
- Diarrhea
- Vomitng
- Cataracts
- E-coli sepsis
GLUT-1
AKA: “devino disease”
“Devino at quatro. Low gluco, opso, micro, treat with Keto, pronto!”
- Presents at 4 months (“quatro”)
- Decreased CSF glucose and serum / csf glucose ratio (low gluco)
- Microcephaly (Micro)
- abnormal eye movemements resembling opsoclonus
- Apnea (why its “pronto”)
- Treat with ketogenic diet
lowes syndrome
AKA
Gene / chromosome
features by category:
A (5)
B (7)
C (2)
D (1)
- AKA occulocerebrorenal cyndrome
- Inheritance: X-linked recessive
- Mutation in OCRL1 (xq26)
- Symptoms
- Occulo
- bilataeral caeracts
- glaucoma
- +/- buphthalmos (bulging eyes)
- Corneal cheloids
- blindness
- Cerebro
- seizures
- developmental regression
- myotonia
- neuropathy with decreased DTR
- obsessive-compulsive-like behavior
- MRI
- periventricular cysts
- Increased signal at periventricular region
- Renal
- RTA
- Renal fanconi syndrome
- Bone
- can also develop ricketts
- Occulo
Palazeus Merzbacher disease (classic form)
Inheritance
Mutation / chromosome
Symptoms
- X-linked recessive
- Proteolipid protein (PLP1) on Xq21-22
- Symptoms: “‘Pleaz keep your eyes open for roving tigers, got it?’ (everyone nods)”
- Optic atrophy
- Roving eye movements
- “tigroid” appearance on MRI (hypomyelinating appearnce on MRI)
- tremor / head nodding

Palazeus-Merzbacher (Connatal form)
Inheritance
How it is different from classic form
Most are AR, but some still x-linked
Presents Earlier and progresses faster (die within first decade)
Tauri’s Disease
Inheritance
Symptoms (3)
Autosomal recessive
- Symptoms similar to McArdle’s disease (exercise-induced cramps and myoglobinuria) EXCEPT:
- NO second wind phenomenonon
- Typically more severe than McArdles (not always)
Forearm ischemia test:
Normal results and what disease does this NOT exclude?
Low Lactate
Low Ammonia
- Normal results
- Rise in lactate
- Rise in Ammonia
- Carnitine Palmitoyltransferase deficiency
- Low lactate
- McArdles
- Tauri’s
- Low Ammonia
- Myoadenylate deaminase defiency
8 months old with lethargy, vomiting, and cardiopulmonary arrest and hypoketotic hypoglycemia:
What disorder do you suspect?
what kind of disorder is it?
Biggest concern
Treatment
Medium-chain Acyl-CoA dehydrogenase Deficiency (MCAD)
autosomal recessive
most commmon disorder of Fatty acid oxidation
Hypoketotic hypoglycemia (this can be fatal!)
Treatment
Low fat diet
Carnitine
Newborn with hyOthermia and hypERbilirubinemia returns at 3 months with concerns of NAT, found to have exaggerated startle response and seizures.
What exam finding would stop you from calling CPS?
What is the mechanism?
inheritance
other features
Menke’s Kinky Hair disease
Disorder of Copper transport
Features: neonate presenting with hypothermia and hyperbili, then at 2-3 months develops seizures, hypotonia, poor feeding, and stimulation induced myoclonus.
Can see Stroke / subdural hemorrhages, Retinal hemorrhages, and rib fractures (can mimic child abuse)
Cherubic face with kinky hair
“wormean bones”
(X-linked recessive)
MELAS
full name
Features
Mitochondrial encephalopathy with lactic acidosis and stroke-like-episodes
Symptoms:
- “Me Lass Lucy GIVES it Out for $10 at Carnivals. She’ll run you Ragged”
- Lucy = defect of Leucine tRNA gene
- GTC
- Intolerance for exercise
- Vomiting
- Elevated Lactate
- Short stature and Sensorineuronal hearing loss
- Occipital distribution for stroke-like episodes (don’t follow vascular distribution)
- Treatment
- Coenzyme Q10
- Carnitine
- _Ragged-_Red Fibers

Baby presents with alternating episodes of diarrhea and pseudoobstruction. also with weakness, ptosis, and ophtamolplegia
What other test could you order to confirm disease and what would it’s finding be?
Mitochondrial Neurogastrointestinal encephalomyopathy
EMG (sensorineuronal neuropathy)
Multiple Sulfatase deficiency
Inheritance
what is the defect?
What are the symptoms?
- Sulfatase Modifying Factor -1 gene (SUMF1)
- Autosomal recessive
- Symptoms: “hunter in the streets, Metachromatic leukodystrophy In the sheets”
- Skeletal symptoms similar to Hunters but with Ichthyiosis
- Neuronal symptoms similar to metachromatic leukodystrophy
MERRF
Full name
Features
Myoclonic epilepsy with ragged red fibers
Features: “MERRF lystened to her dad in the movie ‘Interstellar’ when she was small, and saved a LOAD of Nervous Men
- Mutation in Lysine tRNA
- short stature
- Lipomas
- Optic
- Atrophy
- Deafness
- Neuropathy
- Myopathy
Neimann Pick disease, type C
Inheritance
disorder of ____
Mutation (2) and chromosome (2)
Neonatal presntation
childhood presentation (and age)
- Autosomal recessive
- disorder of Transport of Cholesterol (Type-_C_)
- muations
- NPC1 (18q)
- NPC2 (14q)
- Neonatal presentation
- hepatomegaly
- jaundice
- hypotonia
- Later (3-8 years) = 6 C’s, 4 D’s
- Clumsiness progressing to Ataxia
- Cataplexy
- Choreoathetosis
- “sea”-blue histiocytes and foamy cells
- “see” vertical supranuclear ophthalmoplegia
- “sei”-zures
- Dystonia
- Dysphagia
- Dysarthria
- Dementia
Mutation in Pyridoxine dependency, and how it leads to seizures
Autosmal recessive mutation in ALDH7A1 leads to deficiency in antiquin
Leads to an accumulation of P6C which causes Pyridoxyl-5-phosphate to precipitate out
This leads to inability to convert Glutamate (excitatory) to GABA (inhibitory)
Sialidosis
Inheritance
disease type
defective enzyme
symptoms (main form)
other presentation
common feature between the two
- Autosomal recessive
- Lysosomal storage disorder
- Alpha-neurominidase (sialidase)
- main presentation: progressive myoclonic epilepsy
- Other presentation is similar to Hurler’s but with HSM
- Common feature: cherry red spot on macula
Tangier disease
Inheritance
Mutation
symptoms (5)
lab findings (3)
Autosmal recessive mutation in ATP-binding casset protein 1 gene (ABCA-1) (9q)
Symptoms:
- Large, orange tonsils
- lymphadenopathy
- splenomegaly
- Distal upper extremity Sensory neuropathy leading to Atrophy of hand muscles
Lab findings
- LOW cholesterol
- LOW LDL
- VERY LOW HDL
Wilson’s disease
Inheritance and mutation
result of mutation
Presentation (if < 10 years)
presentation (if >10 years)
Diagnostic tests (4)
Treatment
- Autosomal recessive mutation in ATP7B (13q) (adenosine triphosphatase)
- Leads to inability to transport copper from hepatocytes into Bile
- Symptoms (<10)
- Liver disease
- Symptoms (>10)
- Wing-beating tremor
- Kayser-Fleischer ring
- Sunflower cataracts
- Risus sardonicus (also seen in Tetanus)
- Labs
- LOW serum ceruloplasmin
- LOW serum Copper
- HIGH 24 hour urinary copper excretion
- MRI = “giant panda face)
- Decreased T2 signal in superior calliculi
- increased T2 signal in meidla substantia nigra and tegmentum
- Treatment = “TRI-DAZ” chelation
- TRIethylene Tetramine Dihydrochloride
- D. Penicillimine
- Ammonium Tetrahiomolybate
- Zinc
Differences between Menke’s kinky hair disease and Wilson’s disease
Menke's = _alpha_ subunit of ATP-ase \> problem with **_A_**bsorption Wilsons = _Beta_ subunit of ATP-ase \> problem with **_B_**ile
Wolman disease
Inheritance
defective Enzyme
Onset
symptoms
- Autosmal recessive
- Disorder of acid-lipase >> xanthomatous changes to many organs
- Onset in Infancy, memnonic = “WOAH Man, Just Calm Down”
- Weight loss
- hypOtonia
- Acid-Lipase and Adrenal Insufficiency
- Hepatosplenomegaly
- Malabsorption
- Jaundice
- Calcified adrenal glands
-
Diarrhea and Developmental Delay
9.
Photosensitivity in HARTNUP disease is due to what?
Niacin deficiency
potential Trap:
ABCD1 mutation
-Versus-
ABCA1 mutation
ABCD1 mutation - adrenal leukodystrophy (xlr)
ABCA1 mutation - Tangier Disease (ar)
Diseases with Cherry Red Macula (mnemonic)
Farber Salivates Getting cherry-_picked_, half-off sales at S__acks fifth avenue and Neiman marcus
Farber’s disease
Sialidosis
GM1 gangliosidoses
Neiman-Pick
sandhoff (half-off)
Tay-Sachs
Neiman-Pick type A
How often should asymptomatic patients with x-linked adrenal leukodystrophy get imaged?
Yearly until age 3
then every 6 momths between age 3-12 years
then back to yearly
What is this
Trichrome Gomori Stain
Ragged red fibers

Kearns-Sayres Syndrome
Inheritance
onset
symptoms (2 big + 3 more)
- Mitochondrial
- Onset typically before 20
- Symptoms
- Chronic progressive external opthalmoplegia
- Pigmentary retinopathy
- Cerebellar ataxia
- proximal muscle weakness
- deafness
Leigh’s disease
AKA
Arguably same disorder as _____
Inheritance
Features
Treatment (2)
AKA: acute necrotiing encephalomyelopathy
Arguably same disorder as: Pyruvate dehydrogenase deficiency
Inheritance: Mitochondrial disorder, but multiple causes (mitochondrial, autosom. rec., X-linked)
Features: Princess LEIGH-A
- Lactic acidosis, Lack of milestones (developmental delay)
- Epilepsy / Extraocular movement abnormalities
- Increased T2 signal in putamen
- Gag/Vomit
- Hyperventilation / Hypotonia
- Ataxia_,_ Apnea
Treatment:
- Ketogenic diet
- Supplement Leucine and Lycine
NARP synrome and related disease
- *N**eurogenic muscle weakness
- *A**taxia
- *R**etinitis Pigmentosa
Mitochondria mutation showing heteroplasmy
- 70-90% NARP
- 100% leigh syndrome
Homocystinuria
inheritance / genes
symptoms
Mutliple genes, but all AR (MC = cystathionine B-synthase)
Symptoms
- Marfinoid features
- Ectopia Lentis
- Codfish vertebrae
- Levido reticularis
- MR
- Seizures
- malar flush
- thromboembolism
- myopia
Labs
- Increased homocysteine in urine
- increased homocystine and methionine in blood
Neiman Pick type A
aka
inheritance
Features
prognosis
- AKA infantile neuropathic variant
- persistent neonatal jaundice
- Pulmonary infiltrates
- lymphadenopathy
- cherry-red spot
- foamy macrophages
- Rapid neurologc decline
Neiman Pick type B
Symptoms (5)
Hypersplenism leading to decreased platelets
HSM
ILD
HLD
often survive into adulthood
Pompe’s disease
Inheritance
Defective enzyme
Symptoms
- Infantile
- Juvenile
- adult
Test
Pompe’s disease
- Inheritance (autosomal recessive) defect in alpha 1,4-glucosidase or acid maltase
Symptoms (Infantile) - onset 1-2 months
- Weakness
- “plumpe’s disease”
- Macroglossia
- hepatomegaly
- cardiomegaly
- Death from respiratory collapse
Symptoms (juvenile)
- Diaphragmatic / other respiratory muscle weakness
- Lower limb weakness
Symptoms (adult)
- generalized weakness
- especially muscles of respiration
test = PAS acid schiff (+)
Von Girke’s disease
inheritance
defective enzyme
symptoms (3)
- Autosomal recessive
- Deficient glucose-6-phosphatase >> no gluconeogenesis and no free glucose from glycogenolysis
- Symptoms
- Severe fasting hypoglycemia
- high liver glycogen
- Developmentla delay from repeated hypoglycemia
Cori’s Disease
Inheritance
defective enzyme
Symptoms
- autosomal recessive
- debranching enzyme (lots of unbranched glycogen molecules)
- Symptoms
- similar to Von-Girke’s but milder in presentation
Pyruvate dehydrogenase deficiency
- Inheritance (3)
- Difficient enzyme
- Symptoms
- Treatment
- Autosomal recessive, x-linked, and Mitochondiral
- …look at the name
- Symptoms
- Lactic acidosis with normal pyruvate / lactate ratio
- neurodevelopmental problems
- early death
- Treatment
- Ketogenic diet
- supplementation of Lysine and leucine
Phenylketonuria
- Inheritance
- deficient enzyme
- Symptoms (2)
- Treatement (2)
- Autosomal recessive
- reduced activity of phenylalanine hydroxylase
- > tyrosine becomes essential
- > phenylalanine accumulates and is converted into phenylketone, excreted in urine, hence the name
- Symptoms
- Developmental delay
- seizures
- Treatment
- Low pHe diet
- protein supplementation
Hunters / Hurlers
Inheritance
Enzymes
Symptoms (4 each)
Hunters
- Inheritance = x-inked recessive
- Deficient enzyme: iduronate sulfatase
- Symptoms
- (mild versus hurlers)
- Gargolysm
- HSM
- Developmental delay
Hurlers
- Inheritance: autosomal recessive
- deficient enzyme: B-L-iduronidase
- Symptoms
- Gargolysm
- HSM
- Developmental delay
- Corneal Clouding
Lesh-Nyhan Disease
Inheritance
AKA
Symptoms (5)
- X-linked recessive
- hypoxanthine guanine phosphoribsyltransferase defiicnecy (Xq26)
- Normal at birth
- Hypertonia (often mis-diagnosed as CP)
- delayed milestones
- aggressive behavior
- self-mutilation (biting of fingers, lips, and cheeks)
How would you treat this patient?

Wilson’s disease = TRI-DAZ chelation
- Triethylene tetramine Dihydrochloride
- D. Penicillamine
- Ammonium tetrathiomolybdate
- zinc
- Chelation
Gold standard for diagnosis Wilson’s disease
Hepatic copper concentration (>250 mcg/gram
Patient presents with loss of central vision, optic nerve atrophy first affecting one eye, then spreading to the other. He is subsequently found to have an inherited condition.
What findings would you see on fundoscopy?
How would you treat it?
Fundoscopy:
- vascular tortuosity of retinal vessels
- hyperemia of optic disc
- Peripapillary telangiectasias
Treatment:
- idebenone
(Working list)
Baby presenting with “opisthotonus” what items are on differential?
Maple syrup urine disease
Glutaric acidura type I
Canavan’s disease
neonatal seizure patient with lense dislocation
what is the disorder?
what is the defective enzyme?
what is causing the lense dislocation?
- what is the disorder?
Sulfatite oxidase deficiency - what is the defective enzyme?
molybdenum cofactor deficiency - what is causing the lense dislocation?
caused by bildup of s-sulfacysteine
Mucopolysaccharidoses:
- Inheritance
- Diseases with Mental Retardation (4)
- disease with normal intelligence (4)
- All are automal recessive except Hunters (x-linked)
- Diseases with MR
- Hurler
- Hunter
- Sanfilippo
- Sly
- Diseases with normal intelligence
- Scheie
- Hurler-Scheie
- Morquio
- Maroteaux-Lamy
Mucopolysaccharidoses:
- Defective enzymes (4 most common)
- Common histologic buzzword
- Neurosurgical complication they are at risk for and why
- Defective enzymes (most common)
- alpha-L-iduronidase (hurler, sheie, and hurler-scheie)
- iduronate slfatase (hunter)
- Galactose-6-sulfatase (morquio
- Hyaluronidase (sly)
- Common histologic buzzword
- Zebra bodies (intralysosomal inclusion bodies)
- At risk for obstructive hydrocephalus or cervical cord compression due to skeletal deformities
AADC deficiency
What does the name stand for?
What is the core issue?
Age of onset?
Symptoms + how to confirm diagnosis
Aromatic-L-Amino Acid Decarboxylase deficiency
Core issue = Can’t produe Dopamine and Serotonin
Mnemonic for Symptoms and diagnosis= AAAADDCC
Ataxia
Athetosis
Axial hypOtonia (but limb hypERtonia)
Autonomic Dysfunction
Dystonia/torticollis
C(see) ptosis and occulogyric crisis
increased CSF neurotransmitters
(working list)
Diseases presenting with ichthiosis (3)
Sjogren Larson syndrome
multiple sulfatase deficiency
refsum disorder
11 month old with opisthotonis has this on histology
What is this?
What is the diagnosis
what is the defficient enzyme

Globoid cell (Krabbe)
Defect of galactosylceramidase