7.2 OTHER METABOLIC DISORDERS

Question 1

Which category of disorders involves abnormalities in the heme synthesis pathway and can lead to photosensitivity or neurological symptoms?

Answer 1

Porphyrin Disorders

Question 2

Which group of disorders results from the incomplete breakdown of glycosaminoglycans, leading to their accumulation in tissues and urine?

Answer 2

Mucopolysaccharide Disorders (MPSs)

Question 3

What type of disorders are characterized by abnormalities in purine metabolism, often resulting in excessive uric acid excretion?

Answer 3

Purine Disorders

Question 4

Which category of disorders is associated with abnormalities in sugar metabolism, often detected by the presence of reducing sugars in the urine?

Answer 4

Carbohydrate Disorders

Question 5

Which inherited porphyria is associated with red-stained teeth and port wine-colored urine?

Answer 5

Congenital erythropoietic porphyria.

Question 6

Which porphyria is most associated with acute attacks and increased porphobilinogen?

Answer 6

Acute intermittent porphyria

Question 7

What is the most common acquired porphyria caused by chronic alcohol intake and liver disease?

Answer 7

Porphyria cutanea tarda.

Question 8

Which porphyria is caused by lead poisoning and results in the inhibition of multiple enzymes in the heme pathway?

Answer 8

Lead-induced porphyria.

Question 9

What disorder of purine metabolism causes excessive uric acid excretion, self-destructive behavior, and severe motor defects?

Answer 9

Lesch-Nyhan disease

Question 10

Which mucopolysaccharidosis involves corneal clouding, skeletal abnormalities, and intellectual disability?

Answer 10

Hurler syndrome

Question 11

What sex-linked mucopolysaccharidosis is associated with skeletal abnormalities but no corneal clouding?

Answer 11

Hunter syndrome

Question 12

Which mucopolysaccharidosis results primarily in intellectual disability without physical abnormalities

Answer 12

Sanfilippo syndrome.

Question 13

What disorder is caused by a deficiency in galactose-1-phosphate uridyl transferase (GALT) and can lead to severe symptoms in infants?

Answer 13

Galactosemia

Question 14

Which disorder of carbohydrate metabolism can cause cataracts in adulthood if untreated?

Answer 14

Galactose kinase deficiency.

Question 15

What are the three primary porphyrins in heme synthesis?

Answer 15

Uroporphyrin, coproporphyrin, and protoporphyrin.

Question 16

Which porphyrin precursors are most soluble and appear in the urine?

Answer 16

Aminolevulinic acid (ALA) and porphobilinogen

Question 17

Which porphyrin is not excreted in the urine but analyzed in feces or bile?

Answer 17

Protoporphyrin

Question 18

What test does the CDC recommend for screening lead poisoning?

Answer 18

Free erythrocyte protoporphyrin (FEP) test in whole blood

Question 19

What causes port wine-colored urine in porphyrias?

Answer 19

Oxidation of porphyrins in the urine upon exposure to air

Question 20

What is the difference in symptoms between neurological and cutaneous porphyrias?

Answer 20

Neurological: psychiatric/neurological issues; Cutaneous: photosensitivity

Question 21

What inherited porphyria is associated with red-stained teeth?

Answer 21

Congenital erythropoietic porphyria.

Question 22

What is the purpose of the Ehrlich reaction in porphyrin testing?

Answer 22

Detects ALA and porphobilinogen

Question 23

What color fluorescence indicates a positive porphyrin reaction?

Answer 23

Violet, pink, or red.

Question 24

What are the primary mucopolysaccharides found in urine in MPSs?

Answer 24

Dermatan sulfate, keratan sulfate, and heparan sulfate

Question 25

What inheritance pattern is seen in Hunter syndrome?

Answer 25

Sex-linked recessive

Question 26

What screening tests detect mucopolysaccharides in urine?

Answer 26

Acid-albumin and CTAB turbidity tests.

Question 27

What advanced method is used for qualitative analysis of MPSs?

Answer 27

Liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Question 28

What enzyme deficiency causes Lesch-Nyhan disease?

Answer 28

Hypoxanthine-guanine phosphoribosyltransferase.

Question 29

What are the first signs of Lesch-Nyhan disease in infants?

Answer 29

Orange sand-like uric acid crystals in diapers

Question 30

What symptom is characteristic of Lesch-Nyhan disease besides uric acid accumulation?

Answer 30

Self-destructive behavior.

Question 31

What is the primary concern in galactosuria?

Answer 31

Inability to metabolize galactose, leading to galactosemia.

Question 32

Which enzyme deficiency causes severe galactosemia?

Answer 32

Galactose-1-phosphate uridyl transferase (GALT).

Question 33

What test is used in newborn screening for GALT deficiency?

Answer 33

Enzyme measurement in red blood cells.

Question 34

Which reducing substance test can suggest a carbohydrate metabolism disorder?

Answer 34

Clinitest for reducing substances

Question 35

What dietary change can prevent severe symptoms of galactosemia?

Answer 35

Removal of lactose from the diet.

Question 36

What historical legend is linked to porphyria symptoms?

Answer 36

Vampires (e.g., avoidance of sunlight and port wine-colored urine).

Question 37

What inheritance factor contributed to porphyria among European royals?

Answer 37

Intermarriage and small gene pools.

Question 38

What porphyria is most associated with acute attacks?

Answer 38

Acute intermittent porphyria.

Question 39

What is the hallmark symptom of cutaneous porphyrias like porphyria cutanea tarda?

Answer 39

Photosensitivity leading to skin blistering and scarring upon sun exposure

Question 40

What are the clinical manifestations of acute intermittent porphyria?

Answer 40

Severe abdominal pain, vomiting, neuropsychiatric symptoms (anxiety, psychosis)

Question 41

Which test detects ALA and porphobilinogen in urine?

Answer 41

Ehrlich reaction

Question 42

Which diagnostic method is used to measure porphyrins in urine for porphyrin disorders?

Answer 42

High-pressure liquid chromatography (HPLC)

Question 43

What is the treatment for acute attacks of porphyria?

Answer 43

Intravenous glucose and heme therapy, along with avoiding triggers like alcohol or medications

Question 44

Which substances accumulate in the urine in mucopolysaccharide disorders?

Answer 44

Dermatan sulfate, keratan sulfate, and heparan sulfate

Question 45

Which two MPS disorders involve severe intellectual disability and skeletal abnormalities?

Answer 45

Hurler syndrome and Hunter syndrome

Question 46

What is a key feature of Sanfilippo syndrome?

Answer 46

Intellectual disability without severe skeletal abnormalities

Question 47

What diagnostic tests are used to screen for mucopolysaccharide disorders?

Answer 47

Acid-albumin test, cetyltrimethylammonium bromide (CTAB) turbidity test, and metachromatic staining spot test

Question 48

What modern diagnostic method is used to confirm MPSs?

Answer 48

Liquid chromatography-tandem mass spectrometry (LC-MS/MS)

Question 49

What enzyme deficiency causes Lesch-Nyhan disease?

Answer 49

Hypoxanthine-guanine phosphoribosyltransferase (HGPRT)

Question 50

What are the clinical symptoms of Lesch-Nyhan disease?

Answer 50

Severe motor defects, intellectual disability, self-destructive behavior, gout, and renal calculi

Question 51

What is a key sign of Lesch-Nyhan disease in infants?

Answer 51

Orange sand-like uric acid crystals in diapers

Question 52

What complications are commonly associated with Lesch-Nyhan disease?

Answer 52

Gout, kidney stones, and psychiatric symptoms

Question 53

How is Lesch-Nyhan disease diagnosed?

Answer 53

Urinary excretion of uric acid crystals and genetic testing for HGPRT deficiency

Question 54

What enzyme deficiency is most commonly associated with severe symptoms of galactosemia?

Answer 54

Galactose-1-phosphate uridyl transferase (GALT)

Question 55

What are the common symptoms of galactosemia in infants?

Answer 55

Failure to thrive, liver damage, cataracts, and intellectual disability

Question 56

What is the result of GALK (galactokinase) deficiency?

Answer 56

Cataracts in adulthood without severe developmental symptoms

Question 57

Which other sugars can lead to melituria, besides galactose?

Answer 57

Lactose, fructose, and pentose

Question 58

What is the screening test for galactosemia in newborns?

Answer 58

Measurement of GALT enzyme activity in red blood cells

Question 59

What diagnostic test is used for diagnosing galactosemia and other carbohydrate metabolism disorders?

Answer 59

Chromatography to identify the specific sugars in urine