metabolic disorders 2 Flashcards

1
Q

Describe Inborn Errors of Metabolism.

A

Rare monogenic diseases resulting in deficient activity in a single enzyme in a pathway of intermediary metabolism. Some have deleterious effects very early in life and can be treated or compensated for relatively easily.

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

What are some examples of inherited metabolic diseases tested for at birth related to amino acid metabolism disorders?

A

Examples include phenylketonuria (PKU), maple syrup urine disease (MSUD), homocystin (pyridoxine unresponsive) (HCU).

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

Define Amino Acid Metabolism Disorders.

A

Conditions such as phenylketonuria (PKU), maple syrup urine disease (MSUD), and homocystinuria (HCU) that affect the metabolism of amino acids.

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

How do Inborn Errors of Metabolism manifest in individuals?

A

They result in deficient activity of a single enzyme in a metabolic pathway, leading to various symptoms and effects depending on the specific disorder.

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

Describe the symptoms and effects of Albinism.

A

Albinism results in a lack of pigmentation, white hair, and pink skin due to the deficiency in melanin synthesis from tyrosine.

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

What is the incidence of Alkaptonuria?

A

The incidence of Alkaptonuria is less than 0.4 per 100,000 individuals.

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

Explain the defective process in Homocystinuria.

A

Homocystinuria involves the defective methionine degradation process due to a deficiency in cystathionine β-synthase.

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

What are the symptoms of Maple Syrup Urine Disease?

A

Maple Syrup Urine Disease can lead to vomiting, convulsions, intellectual development disorders, and early death due to the degradation of isoleucine, leucine, and valine.

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

Define Phenylketonuria (PKU).

A

Phenylketonuria is a condition where there is a conversion issue of phenylalanine to tyrosine due to a deficiency in phenylalanine hydroxylase, leading to symptoms like neonatal vomiting and intellectual development disorders.

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

Describe Maple syrup urine disease.

A

A genetic disorder involving the degradation of isoleucine, leucine, and valine due to a deficiency in the branched-chain α-ketoacid dehydrogenase complex, leading to symptoms like vomiting, convulsions, and intellectual development disorders.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the mode of inheritance for Alkaptonuria?

A

Alkaptonuria is inherited in a recessive manner.

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

Define Albinism.

A

A genetic condition with a low incidence characterized by a lack of pigmentation, resulting in white hair and pink skin.

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

How does Phenylketonuria affect individuals?

A

Phenylketonuria is a disorder that hinders the conversion of phenylalanine to tyrosine due to a deficiency in phenylalanine hydroxylase, leading to symptoms like neonatal vomiting and intellectual development disorders.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Do individuals with Argininaemia experience any specific symptoms?

A

Argininaemia, caused by a deficiency in arginase, can lead to intellectual development disorders.

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

Describe Homocystinuria.

A

Homocystinuria is a condition resulting from faulty bone development and intellectual development disorders due to defects in the methionine degradation pathway.

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

How is Alkaptonuria characterized in terms of symptoms?

A

Alkaptonuria is characterized by dark pigment in urine and late-developing arthritis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What enzyme is deficient in Homogentisic acid oxidase deficiency?

A

Homogentisic acid oxidase is deficient in Homogentisic acid oxidase deficiency.

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

Define Carbamoyl phosphate synthetase 1 deficiency.

A

Carbamoyl phosphate synthetase 1 deficiency is a condition affecting urea synthesis, leading to symptoms like lethargy, convulsions, and early death.

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

Describe the symptoms of Maple syrup urine disease.

A

Maple syrup urine disease involves symptoms like vomiting, convulsions, and intellectual development disorders, ultimately leading to early death.

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

Describe the symptoms associated with methylmalonic acidaemia (MMA).

A

Symptoms of MMA include vomiting, convulsions, intellectual development disorders, and early death.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the enzyme deficiency in phenylketonuria?

A

Phenylalanine hydroxylase deficiency.

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

Define Alkaptonuria.

A

Alkaptonuria is a genetic disorder characterized by the accumulation of homogentisic acid, leading to dark pigment in urine and late-developing arthritis.

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

How is argininaemia diagnosed?

A

Argininaemia is diagnosed by measuring levels of arginine in the blood, which are typically elevated.

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

Do individuals with maple syrup urine disease have faulty bone development?

A

Yes, individuals with maple syrup urine disease may have faulty bone development along with intellectual development disorders.

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

Describe the consequences of homocystinuria.

A

Homocystinuria can lead to lethargy, convulsions, and early death, along with faulty bone development and intellectual development disorders.

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

What is the main toxic compound that accumulates in tissues in methylmalonic acidaemia?

A

Propionyl-CoA and methylmalonyl-CoA accumulate to toxic levels in tissues in methylmalonic acidaemia.

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

Define the enzyme deficiency in carbamoyl phosphate synthetase 1 deficiency.

A

Carbamoyl phosphate synthetase 1 deficiency is caused by a deficiency in the enzyme carbamoyl phosphate synthetase 1.

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

How are neonates with methylmalonic acidaemia typically during the first 1-2 weeks of life?

A

Neonates with MMA are typically healthy during the first 1-2 weeks of life before symptoms such as hypotonia, lethargy, and poor feeding may appear.

29
Q

Describe the genetic disorder arginosuccinase acidaemia.

A

Arginosuccinase acidaemia is characterized by intellectual development disorders, vomiting, and convulsions due to a deficiency in the enzyme arginosuccinase.

30
Q

What are the symptoms of argininaemia?

A

Symptoms of argininaemia include intellectual development disorders and elevated levels of arginine in the blood.

31
Q

How is phenylketonuria diagnosed?

A

Phenylketonuria is diagnosed through newborn screening tests that measure phenylalanine levels in the blood.

32
Q

Describe the symptoms of individuals with branched-chain ketoaciduria (maple syrup urine disease).

A

Individuals with maple syrup urine disease may experience vomiting, convulsions, intellectual development disorders, and early death.

33
Q

What is the main enzyme deficiency in homocystinuria?

A

Homocystinuria is caused by a deficiency in the enzyme cystathionine β-synthase.

34
Q

How is Alkaptonuria characterized?

A

Alkaptonuria is characterized by white hair, pink skin, and the accumulation of homogentisic acid.

35
Q

Do individuals with arginosuccinase acidaemia experience vomiting and convulsions?

A

Yes, individuals with arginosuccinase acidaemia may experience vomiting and convulsions along with intellectual development disorders.

36
Q

Describe the genetic disorder carbamoyl phosphate synthetase 1 deficiency.

A

Carbamoyl phosphate synthetase 1 deficiency leads to symptoms such as lethargy, convulsions, and early death due to impaired urea synthesis.

37
Q

What are the symptoms of individuals with homocystinuria?

A

Symptoms of homocystinuria include lethargy, convulsions, and early death, along with faulty bone development and intellectual development disorders.

38
Q

How is methylmalonic acidaemia diagnosed in neonates?

A

Methylmalonic acidaemia is diagnosed based on symptoms such as hypotonia, lethargy, and poor feeding in neonates.

39
Q

Define the enzyme deficiency in arginosuccinase acidaemia.

A

Arginosuccinase acidaemia is caused by a deficiency in the enzyme arginosuccinase.

40
Q

Describe the symptoms of individuals with phenylketonuria.

A

Individuals with phenylketonuria may experience neonatal vomiting and intellectual development disorders due to the inability to convert phenylalanine to tyrosine.

41
Q

How is MMA different from ethylene glycol poisoning in terms of symptoms?

A

MMA and ethylene glycol poisoning have almost identical symptoms, with MMA causing toxic levels of D/L-methylmalonic acid accumulation in tissues, blood, and urine.

42
Q

Do individuals with MMA typically present with hypotonia, lethargy, and poor feeding?

A

Yes, individuals with MMA, especially those with severe mutations, typically present with hypotonia, lethargy, and poor feeding.

43
Q

Describe the consequences of propionyl-CoA carboxylase deficiency in MMA.

A

Propionyl-CoA carboxylase deficiency in MMA leads to the accumulation of toxic levels of propionyl-CoA and methylmalonyl-CoA in tissues, blood, and urine.

44
Q

How is MMA diagnosed in neonates with severe mutations?

A

MMA is diagnosed in neonates with severe mutations based on symptoms such as hypotonia, lethargy, and poor feeding.

45
Q

Define the enzyme deficiency in propionyl-CoA carboxylase deficiency in MMA.

A

Propionyl-CoA carboxylase deficiency in MMA is caused by a deficiency in the enzyme propionyl-CoA carboxylase.

46
Q

Describe the symptoms of neonates with MMA during the first 1-2 weeks of life.

A

Neonates with MMA are typically healthy during the first 1-2 weeks of life before symptoms such as hypotonia, lethargy, and poor feeding may appear.

47
Q

How is MMA similar to ethylene glycol poisoning in terms of symptoms?

A

MMA and ethylene glycol poisoning have almost identical symptoms, with MMA causing toxic levels of D/L-methylmalonic acid accumulation in tissues, blood, and urine.

48
Q

Do individuals with MMA typically present with poor growth or only have symptoms during periods of intervening illness?

A

Yes, individuals with MMA, especially those with milder mutations, may present with poor growth or only have symptoms during periods of intervening illness.

49
Q

Describe the symptoms associated with Maple syrup urine disease.

A

Symptoms includeargy, seizures, and hypoglyemia.

50
Q

Define Adenosylcobalamin (AdoCbl) and its relation to Vitamin B12.

A

Adenosylcobalamin is a coenzyme derived from Vitamin B12.

51
Q

What is the prevalence of CblA (MMAA) in AdoCbl synthesis?

A

CblA (MMAA) accounts for 25% of AdoCbl synthesis.

52
Q

How is Methylmalonyl-CoA Mutase related to the condition MMA?

A

Methylmalonyl-CoA Mutase is the defective enzyme in MMA.

53
Q

Describe the management approach for Methylmalonic acidemia.

A

It involves a highly modified protein-restricted diet, amino acid supplements, cobalamin supplementation, and L-carnitine supplementation.

54
Q

What is the prognosis for patients with MUT0 subtype of the condition?

A

MUT0 subtype has the worst prognosis.

55
Q

Define Albinism and its effects on pigmentation.

A

Albinism is characterized by a lack of pigmentation, resulting in white hair and pink skin.

56
Q

Describe the symptoms associated with Argininaemia.

A

Argininaemia presents with intellectual development disorders.

57
Q

What enzyme is defective in Homocystinuria, and what are its effects?

A

Cystathionine β-synthase is defective in Homocystinuria, leading to faulty bone development and intellectual development disorders.

58
Q

How does Maple syrup urine disease affect branched-chain amino acid catabolism?

A

MSUD is a disorder of branched-chain amino acid catabolism, leading to distinctive symptoms like vomiting, convulsions, and intellectual development disorders.

59
Q

Describe the disease mechanism of Maple syrup urine disease.

A

High levels of Leu block LNAA transporter, causing a build-up of α-ketoacids that enter the brain and deplete glutamate, leading to neurological damage and other symptoms.

60
Q

Describe the condition of Maple syrup urine disease.

A

Maple syrup urine disease is a rare disorder with an incidence of less than 0.4 per 100,000 individuals. It involves a defective process in branched-chain amino acid metabolism, specifically affecting the enzyme branched-chain α-ketoacid dehydrogenase complex. Symptoms include vomiting, convulsions, intellectual development disorders, and early death.

61
Q

Define Alkaptonuria and its effects.

A

Alkaptonuria is a condition with an incidence of less than 0.4 per 100,000 individuals, characterized by a defect in tyrosine degradation due to a deficiency of homogentisate 1,2-dioxygenase. It leads to the presence of dark pigment in urine and late-developing arthritis.

62
Q

How is Argininaemia characterized and what are its symptoms?

A

Argininaemia is a rare condition with an incidence of less than 0.5 per 100,000 individuals, affecting urea synthesis due to a deficiency of arginase. It is associated with intellectual development disorders and symptoms like vomiting and convulsions.

63
Q

Do you know the treatment approach for Phenylketonuria (PKU)?

A

The treatment for Phenylketonuria involves maintaining very low levels of dietary phenylalanine (Phe). There is no cure, and treatment should begin within the first week of life with the goal of achieving target Phe levels within the first two weeks.

64
Q

Describe the impact of increased levels of Phenylalanine (Phe) in Phenylketonuria.

A

Increased levels of Phenylalanine in Phenylketonuria lead to decreased levels of Tyrosine, disrupting brain development. This disruption can result in profound intellectual disorders, microcephaly, epilepsy, and other neurological symptoms.

65
Q

What is the significance of the Guthrie test in the context of Phenylketonuria?

A

The Guthrie test is used to detect Phenylketonuria by testing for Phenylalanine (Phe) and its catabolites. It is based on inhibiting bacterial growth, where excess Phe or its catabolites overcome the inhibition and restore bacterial growth, indicating a positive result for PKU.

66
Q

Define Homocystinuria and its effects on the body.

A

Homocystinuria is a rare genetic disorder with an incidence of less than 0.5 per 100,000 individuals, involving a defect in methionine degradation due to a deficiency of cystathionine β-synthase. It leads to faulty bone development and intellectual development disorders.

67
Q

What are the symptoms and effects of Albinism?

A

Albinism is characterized by a lack of pigmentation, resulting in white hair and pink skin. It is caused by a defective process in melanin synthesis from tyrosine, specifically involving tyrosinase deficiency.

68
Q

Describe the defective process in Phenylketonuria and its consequences.

A

Phenylketonuria is caused by mutations in Phenylalanine hydroxylase, leading to the inability to convert Phenylalanine (Phe) to Tyrosine. This results in high levels of Phe accumulating in the plasma, which can lead to the formation of phenylpyruvate.

69
Q

What is the treatment approach for Maple syrup urine disease?

A

The treatment for Maple syrup urine disease involves dietary protein restriction similar to Phenylketonuria (PKU) and in severe cases, liver transplant may be considered.