Inborn Errors of Metabolism Flashcards

1
Q

What should come to mind when a previously healthy infant develops poor feeding, hypoglycemia, lethargy, vomiting, tachypnea, apnea, irritability, seizures, coma, apnea?

A

Inborn errors of metabolsim

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is often the crucial clue for answers regarding inborn errors of metabolism?

A

Antecedent events, even if they seem inconsequential (like feeding)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What should you focus on with questions regarding inborn errors of metabolism?

A

Specific differences since many are quite similar

Use a logical approach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

If you are presented with a lethargic or comatose infant, what is appropriate to order?

A

CBC, electrolytes, serum ammonia level, and urine organic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

If you are given values for electrolytes, what should you do?

A

Measure the anion gap…

Serum Sodium - [Chloride + Bicarbonate]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is normal anion gap?

A

8-12 mEq/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What should an elevated anion gap in an infant who is lethargic or comatose make you think of?

A

Elevated ammonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What 2 symptoms do all of the metabolic disorders present with?

A
  1. Vomiting
  2. Lethargy

*So distinguishing the fine differences between them can be a challenge… key phrases and wording distinguish one from the other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does it mean if they emphasize that the infant is afebrile?

A

ID tree is the wrong tree…look for other clues in the question that this isn’t an infection (normal WBC count and platelet count)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Metabolic acidosis, Elevated serum ammonia (NH4)…disorders?

A
  1. Propionic acidemia
  2. Methylamalonic acidemia
  3. Fatty acid oxidation defects
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

ABG normal, Elevated serum ammonia (NH4)…disorders?

A
  1. Urea cycle defect

2. Transient hyperammonemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Metabolic acidosis, Normal serum ammonia (NH4)…disorders?

A
  1. MSUD

2. Some organic acidemias

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

ABG normal, Normal serum ammonia (NH4)…disorders?

A
  1. Aminoacidopathy
  2. Galactosemia
  3. Non-ketotic hyperglycinemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a normal serum ammonia value in a newborn?

A

Below 110 mcmol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

In a kid with galactosemia, why might they have a metabolic acidosis?

A

From sepsis… pure galactosemia has a normal ABG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are 3 examples of organic acidemias?

A
  1. Methylmalonic acidemia
  2. Propionic acidemia
  3. Isovaleric acidemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which organic acidemia has an odor of sweaty feet?

A

Isovaleric acidemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What common problem can present with a metabolic acidosis?

A

Sepsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do organic acidemias typically present?

A

With a “drunk-like” intoxicated picture…but the disease is life threatening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are important lab findings in organic acidemias?

A
  1. Elevated serum ammonia levels (in many, but not all)
  2. Acidosis
  3. High anion gap
  4. Ketonuria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When do organic acidemias often present?

A

First 2 days after the introduction of protein in the diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the most important initial step after diagnosing an organic acidemia?

A

HYDRATION…to maintain good urine output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is indicated after you hydrate your patient you have diagnosed with organic acidemia?

A

Appropriate diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the most important laboratory study for organic acidemia?

A

Urine organic acid levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

When they present you with an infant with a septic appearance with sepsis ruled out, what is likely cause?

A

Metabolic (generally)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What should be done next if they present you with an infant with a septic appearance with sepsis ruled out?

A

Obtain a serum ammonia level

Additional correct choices: Lactic acid level, serum pyruvate, total and free carnitine, acetylcarnitine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Why can granulocytopenia and thrombocytopenia occur with organic acidemias?

A

Because metabolic acidosis can suppress bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

If you have a history consistent with organic acidemia and a low platelet and WBC count, is this normal?

A

Could be…metabolic acidosis (from organic acidemias) can suppress bone marrow leading to granulocytopenia and thrombocytopenia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How does a child with organic acidemias present?

A

Decreased appetite, falling down frequently, delayed developmental milestones, with no overt physical abnormalities or dysmorphology

*Think of someone who is drunk…think of organic acids as very powerful alcoholic drinks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Since brain tumors and organic acidemias can both present with balance problems and vomiting, what can help distinguish?

A

If it is a brain tumor they will hint that the symptoms have been progressively worse… might also mention morning headaches and visual disturbances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How are fatty acid oxidation defects inherited?

A

Autosomal recessive pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Name 4 fatty acid oxidation defects?

A
  1. Medium chain acyl-CoA dehydrogenase deficiency
  2. Long chain acyl-CoA dehydrogenase deficiency
  3. Very long chain acyl-CoA dehydrogenase deficiency
  4. Glutaric aciduria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How do infants with a defect in fatty acid metabolism present?

A

Hypoglycemia and hepatomegaly

*Fatty acid oxidation defects may or may not present with hepatomegaly…it may be part of the presentation on boards however

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What preceding signs should you watch for with fatty acid oxidation defect?

A

Preceding benign illness during which oral intake was decreased (this could occur in a toddler)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

When do many of the signs of fatty acid oxidation defects present?

A

With fasting (why you have to watch for illness with associated oral intake)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

True or false: In between episodes of fasting, a child with a defect in fatty acid metabolism is fine?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is seen in urine and serum with defects in fatty acid metabolism?

A

Absence of reducing substances and ketones in urine

Normal serum amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How is definitive diagnosis of a defect in fatty acid metabolism made?

A

Via plasma acylcarnitine profile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

How do urea cycle defects present?

A

With hyperammonemia in the absence of acidosis and ketosis. Also look for a symptom-free period, followed by hypotonia and coma.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What acid-base issues can be present with urea cycle defects?

A

Respiratory alkalosis as well as lactic acidosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What causes symptoms consistent with encephalopathy (vomiting, lethargy, coma) in urea cycle defects?

A

Hyperammonemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is treatment for urea cycle defects?

A

Reduce serum ammonia (NH4) by reducing protein intake and increasing glucose intake by IV… dialysis might be needed on a PRN, usually acute, basis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What does a neonate with hyperammonemia, acidosis, and ketosis have?

A

Organic aciduria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What does a neonate with no acidosis and ketosis, but hyperammonemia have?

A

Urea cycle defects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Infant with hypoglycemia, seizures, hepatomgealy, failure to thrive…most helpful measure to determine etiology?

A

Most important measurements to determine the etiology of hypoglycemia in infants is urine measurement of ketones and reducing substances

*Don’t fall for cortisol and growth hormone (if macrosomic) or insulin level measurement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

When do infants with galatosemia present?

A

After their first meal containing lactose (breast milk or formula)…infants with galactosemia will appear normal at birth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

After consuming lactose, how do babies with galactosemia present?

A

Non-specific findings…poor feeding and failure to thrive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Which states test for galactosemia?

A

All of them…but symptoms may develop before the newborn screen results are recieved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What should be done for a newborn with symptoms of galactosemia or a positive screen for galactosemia?

A

Changed immediately to a soy-based formula and repeat NBS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Name more specific findings of galactosemia

A
  1. Abdominal distension with hepatomegaly
  2. Hypoglycemia
  3. Non-glucose reducing substances in the urine
  4. Lethargy and hypotonia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What should you think with a history of prolonged jaundice and/or infection with gram negative organisms including E. Coli?

A

Galactosemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What is galactosemia due to?

A

Deficiency of galactose-1-phosphate uridyltransferase (GALT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

How is definitive diagnosis of galactosemia made?

A

Measuring GALT in RBCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is treatment of galactosemia?

A

Soy formula…galactose-free diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Failure to treat galactosemia can result in what?

A

Cataracts, intellectual disability, and/or liver disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

True or False: Cataracts due to galactosemia are reversible with diet change?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Since several glycogen storage diseases presents with hepatosplenomegaly, what buzz word should make you think galactosemia?

A

Positive reducing substances in urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What are 3 other diseases that should be in your differential diagnosis for galactosemia?

A
  1. Lactose intolerance
  2. Maple Syrup Urine Disease
  3. Urea Cycle Defects
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

How is lactose intolerance different from galactosemia?

A

Presents later in childhood…much more benign

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

How is maple syrup urine disease different from galactosemia?

A

MSUD presents with hypoglycemia, but also presents with acidosis, increased tone, odor of maple syrup in the urine, seizures

61
Q

How are urea cycle defects different from galactosemia?

A

In addition to lethargy and poor feeding, urea cycle defects present with coma and hyperammonemia

62
Q

How can infants of diabetic mothers present?

A

Hypoglycemia, jitteriness, seizures….Because of exposure to higher than normal serum glucose in utero, these babies have their insulin production going strong… once born and decreased glucose, but still high insulin…hypoglycemic…checking serum glucose is crucial

63
Q

What can be the cause of tremors, apnea, cyanosis, lethargy, and tachypnea in infants?

A

Hypoglycemia

64
Q

Besides hypoglycemia, what 3 things are infants of diabetic mothers at risk for?

A
  1. Hypocalcemia
  2. Hyperbilirubinemia
  3. Polycythemia
65
Q

Icteric 4 day old newborn with lethargy and hepatomegaly. LP is positive for gram negative organisms…what is the best additional study to obtain?

A

Galactose-1-phosphate activity in RBCs (erythrocytes)

Don’t fall for idea of sepsis and positive gram stain of CSF and jump to culture of CSF…hepatomegaly is the give-away

66
Q

What is hepatomegaly and risk for gram-negative sepsis hallmark of?

A

Galactosemia

67
Q

How is galactosemia diagnosed?

A

By measuring galactose-1-phosphate activity in erythrocytes

68
Q

Presented with an infant with a sepsis-like picture, hepatomegaly, and positive culture for gram-negative organisms?

A

Galactosemia lurking in the erythrocyte

69
Q

What is the treatment for galactosemia?

A

Antibiotics and diet restriction

70
Q

What is an associated finding of galactosemia in the urine?

A

Reducing substances in the urine

71
Q

Afebrile infant presenting with generalized seizures. They are hypoglycemic and it is fixed with injection of glucagon?

A

Hyperinsulinism

72
Q

What size (length, weight, head circumference) are babies with hyperinsulinism?

A

Height, weight, and head circumference will all be in the upper limits of normal…typically in the 95th percentile for all parameters

73
Q

Macrosomia, microcephaly, macroglossia, visceromegaly, omphalocele?

A

Beckwith-Wiedemann Syndrome

Don’t confuse with hyperinsulinism…this has macrosomia too, but macrocephaly instead of microcephaly

74
Q

What presents with hypoglycemia and ketonuria?

A

Adrenal insufficiency

  • If they note absence of ketones in urine, they are ruling out adrenal insufficiency for you
  • Don’t confuse with hyperinsulinism..this also has hypoglycemia, but no ketones in urine
75
Q

Hypoglycemia, vomiting, failure to thrive, hepatomegaly, non-glucose reducing substances in the urine?

A

Galactosemia

76
Q

What is hypoglycemia due to in Beckwith-Wiedemann syndrome?

A

Islet cell hyperplasia

77
Q

Full term infant who is hypoglycemic. Serum insulin levels are elevated. Despite glucose IV, still hypoglycemia. What next? Which medication most appropriate?

A

Diazoxide: Decreases insulin secretion and stimulates cortisol release…this is DOC in refractory hypoglycemia in infants

Don’t pick glucagon (this is refractory hypoglycemia)
Don’t pick CCB (even though Ca is needed to squeeze out insulin from pancreas, this rarely helps with refractory hypoglycemia)

78
Q

Features of Glycogen Storage Disease Type I (Von Gierke Disease)?

A
  1. Hypoglycemia
  2. Distended abdomen
  3. Doll-like or cherubic face
  4. Poor growth
  5. Large liver
  6. Seizures (secondary to hypoglycemia)
  7. Elevated triglycerides and cholesterol
79
Q

What are 3 lab findings with Glycogen Storage Disease Type I?

A
  1. Hypoglycemia
  2. Lactic acidosis with fasting (elevated lactic acid)
  3. Elevated uric acid levels
80
Q

What is a common feature in the history of Von Gierke Disease?

A

Consanguinity

81
Q

What is Glycogen Storage Disease Type I caused by?

A

A deficiency of hepatic glucose-6-phosphatase

This is the final step in the liver to produce glucose

82
Q

When do glycogen storage diseases often present?

A

When an infant begins sleeping through the night…aka, “prolonged fasting”

83
Q

What is the treatment for Glycogen Storage Disease Type I?

A
  1. Frequent snacks and meals
  2. Sometimes continuous tube feedings
  3. Sometimes infusion of glucose continuously, especially at night until age of 2 (after 2, cornstarch is often used, since it releases glucose slowly)
84
Q

What are some diversions for wrong treatment or inappropriate initial treatment of Glycogen Storage Disease Type I?

A
  • It is only the continuous feeding of glucose that is helpful
    1. Feeding of formula high in fructose or galactose
    2. Glucagon injections
    3. Liver transplant (might be appropriate down the road in the event of liver failure, but not the appropriate initial treatment of choice)
85
Q

What disease results from a deficiency in lysosomal breakdown of glycogen?

A

Glycogen Storage Disease Type II (Pompe Disease)

86
Q

Infant who is one month of age or younger, normal at birth. Becomes floppy, fails to thrive, develops a large liver with macroglossia, cardiomegaly, hypotonia with muscles that are “hard” on examination?

A

Glycogen Storage Disease Type II (Pompe Disease)

87
Q

What causes death in Pompe Disease?

A

Respiratory failure

88
Q

Memory aid for Glycogen Storage Disease Type II?

A

Instead of Pompe Disease, change it to Pope disease…one feature is cardiomegaly (Pope has a big heart). He isn’t afraid to speak out when necessary, so he has a large tongue (macroglossia)

89
Q

True or False: Hypoglycemia and acidosis are often seen in Pompe Disease?

A

False… hypoglycemia and acidosis aren’t part of Pompe Disease

90
Q

Newborn presenting after being fed protein-containing formula for the first time. Become lethargic and eventually comatose.

A

Nonketotic hyperglycinemia

91
Q

If an infant survives nonketonic hyperglycinemia, what will they often have?

A

Spastic Cerebral Palsy

92
Q

Infant with tachypnea, shallow breathing pattern, profound lethargy, hypertonicity, burnt smell to urine

A

Maple Syrup Urine Disease

93
Q

When is the classic onset of Maple Syrup Urine Disease?

A

First week of life

94
Q

Which amino acids have elevated plasma levels in Maple Syrup Urine Disease?

A
VIAL (picture maple syrup in a vial)
Valine
Isoleucine
Alloisoleucine (never found in normal infants)
Leucine
95
Q

What causes Maple Syrup Urine Disease?

A

Inability to break down the branched chain amino acids (Valine, isoleucine, alloisoleucine, leucine)

96
Q

What is the problem in homocustinuria?

A

Error in methionine metabolism where a cystathionine synthase deficiency results in elevated blood methionine levels and elevated urine homocystine levels

97
Q

Dislocated lenses, skeletal abnormalities, cognitive deficits, unpleasant odor, lighter-colored skin, hair, and eyes than other family members?

A

Homocystinuria

98
Q

How is homocystinuria diagnosed?

A

By confirming homocysteine in the urine

99
Q

What drug can a patient with homocystinuria who has residual enzyme activity respond to?

A

Pyridoxine

100
Q

What is the correct treatment for homocystinuria?

A

Diet high in cysteine and low in methionine

101
Q

What are common features of Marfan Syndrome and Homocystinuria and how do you tell them apart?

A

Both can have dislocated lenses, skeletal abnormalities, tall, thin, pectus excavatum

Marfan: Anterior lens displacement, no cognitive deficits
Homocystinuria: Posterior lens displacement, possible cognitive deficits

102
Q

What causes phenylketonuria (PKU)?

A

Deficiency of enzyme that converts phenylalanine to tyrosine…leads to the accumulation of phenylalanine

103
Q

Why isn’t symptomatic PKU seen in the real world?

A

Due to mandatory newborn screening (it can still be on boards)

104
Q

Blond hair, blue eyes. Asymptomatic for a few months. Then severe vomiting, irritability, eczema, musty/mousy odor of urine.

A

PKU

105
Q

What are 3 later signs of untreated PKU?

A
  1. Microcephaly
  2. Congenital heart disease
  3. Low birthweight
106
Q

What does PKU ultimately lead to?

A

Profound intellectual disability and other neurological impairments

107
Q

If an infant has a positive PKU screen, do they have PKU?

A

Not necessarily… the positive screen only indicates elevated phenylalanine levels

108
Q

What can elevated phenylalanine levels (and a positive PKU screen) be caused by besides PKU?

A
  1. Delayed enzyme maturation
  2. Hyperphenylalaninemia
  3. Biopterin deficiency
109
Q

Why is it important for any Mom with PKU to be treated before conception (if contemplating pregnancy)?

A

Increased risk for miscarriage, SGA, microcephaly, cardiac defects, and intellectual disability

110
Q

Why does a newborn screening have to be done at 48-72 hours?

A

PKU screening is only valid after a “protein” feeding

111
Q

How is PKU treated?

A

With a low phenylalanine formula (Lofenalac)

112
Q

What can be seen in overtreatment of PKU?

A

Increased lethargy, rash, diarrhea. Caused by low phenylalanine levels…because phenylalanine isn’t synthesized in the body, overzealous treatment, especially in rapidly growing infants, can result in phenylalanine deficiency

113
Q

Which amino acid becomes essential in PKU?

A

Tyrosine…adequate intake must be ensured

114
Q

What disorders all present with coarse facies?

A

Mucopolysaccharidoses

115
Q

What are 3 differences between the mucopolysaccharidoses that can help you distinguish between them?

A
  1. Presence/Absence of corneal clouding
  2. Intellectual disability
  3. Modes of inheritance
116
Q

When does Hurler Syndrome present?

A

Before age 2

117
Q

Progressive facial coarsening, hirsutism, hepatosplenomegaly, thick skulls, corneal clouding, severe intellectual disability (along with other neurological deficits)

A

Hurler Syndrome (MPS Type I)

118
Q

What is the significant lab finding in Hurler Syndrome?

A

Reduced alpha-L-iduronidase activity in WBCs

119
Q

Coarse facial features, organomegaly, joint contractures, skin that appears pebbly (especially over the upper back)

A

Hunter Syndrome (MPS Type II)

120
Q

What is the significant lab finding for Hunter Syndrome (MPS Type II)?

A

Reduced iduronate sulfatase enzyme activity in WBCs

121
Q

What are the similarities and differences between Hunter and Hurler syndrome?

A

Same: Hepatosplenomegaly, progressive deafness

Hunter: Short and have skeletal abnormalities, X-linked recessive
Hurler: Corneal clouding

122
Q

Memory aid for Hunter Syndrome?

A

Picture a hunter with a bow and arrow (X-linked)…tips of arrows have giant X’s. Short stature and skeletal abnormalities help then get around while hunting without being seen. No corneal clouding because you have to see in order to hunt.

123
Q

Memory aid for similarities between Hunter and Hurler Syndrome?

A

H pattern…Hunter and Hurler are associated with Hepatosplenomegaly and Hearing deficits

124
Q

What is infantile Gaucher disease due to?

A

Decreased beta glucosidase activity

125
Q

Child in the 1st or 2nd year of life with progressive hepatosplenomegaly and CNS deterioration?

A

Infantile Gaucher disease

126
Q

Splenomegaly with chronic problems including thrombocytopenia or pancytopenia?

A

Chronic juvenile Gaucher Disease (this form isn’t as severe and there usually isn’t any CNS involvement)

127
Q

What child should Gaucher disease be considered in?

A

Any child presenting with hepatosplenomegaly, bone pain, and easy bruisability. Also short stature.

128
Q

What are the symptoms due to in Gaucher disease?

A

Thrombocytopenia (large part)

129
Q

What can be seen on XR in Gaucher disease?

A

Osteosclerosis and lytic lesions

130
Q

Memory aid for Gaucher disease?

A

Picture a Gaucho cowboy falling off of his horse resulting in bone pain, nose bleeds, and lots of bruises

131
Q

How does Tay Sachs Disease present?

A

With progressive neurologic degeneration of the first year of life, with death occurring by age 4 or 5

132
Q

What causes Tay Sachs Disease?

A

Deficiency of activity in the hexosaminidase A enzyme (this is a lysosomal enzyme)

133
Q

How is Tay Sachs Disease inherited?

A

Autosomal recessive

134
Q

Normal development through first 9 months. Then non specific signs like lethargy and hypotonia. Also get exaggerated startle reflex, cherry red spot on the retina, and macrocephaly.

A

Tay Sachs Disease

135
Q

What is the progression of Tay Sachs Disease?

A

Continued deterioration, including blindness and seizures. Death occurs by age 5.

136
Q

Which ethnic groups does Tay Sachs Disease occur in?

A

Ashkenazi Jews, French Canadians

Screening is recommended even when only one parent is at risk based on ethnicity

137
Q

Cherry red spot on the retina, CNS deterioration, hepatosplenomegaly…

A

Niemann-Pick Disease

138
Q

Memory aid for Niemann-Pick?

A

Pick Axe attacking the liver and spleen causing inflammation

139
Q

What are 2 ways you can do prenatal screening for many conditions?

A

Amniocentesis or CVS sampling

140
Q

When should prenatal screening for specific non-NBS conditions take place?

A

Family history of deaths due to metabolic disorders, ethic background, and geographical origin. Ethic and racial profiling is appropriate and helpful. Parents’ carrier status doesn’t need to be known…don’t pick a choice based on parents’ carrier status.

141
Q

Name the 3 lysosomal/lipid storage diseases (spingolipidoses)?

A
  1. Gaucher Disease
  2. Tay Sachs Disease
  3. Niemann-Pick Disease
142
Q

Previously healthy infant with new onset of lethargy, vomiting, tachypnea, apnea, irritability, or seizures?

A

Inborn errors of metabolism

143
Q

Late infancy or early childhood, slowly progressive symptoms?

A

Lipid storage disease

144
Q

When meals are more spread out (when the infant is sleeping more) is when this group of disorders presents.

A

Glycogen storage disease

145
Q
  1. Presents when meals are more spread out (infant sleeping more)
  2. Illness or stress increases metabolic demands, leading to hypoglycemia, metabolic acidosis, and hyperammonemia
  3. Nonketotic
A

Fatty acid oxidation disorders

146
Q

Metabolic acidosis, increased anion gap, hyperammonemia, hypoglycemia

A

Organic acidemias

Remember that neutropenia and thrombocytopenia can be a part of the picture with organic acidemias

147
Q

Hyperammonemia without acidosis, respiratory alkalosis

A

Urea cycle defects

148
Q

Acidosis and hypoglycemia

A

Amino acid disorder

149
Q

Acute encephalopathy, no metabolic acidosis, no hyperammonemia

A

Non-ketotic hyperglycinemia