Module 02: Inborn Errors of Metabolism Flashcards
This pertains to the inherited diseased caused by interruptions in the various pathways involved in the metabolism of proteins, carbohydrates and or lipids.
Inborn errors of metabolism
What are the modes of transmission for IEM?
Autosomal recessive or X-linked.
Why is early diagnosis and treatment important for IEM?
Early diagnosis and prompt treatment are essential to prevent relentless course of physical and mental deterioration
Do IEMs usually produce symptoms immediately after birth?
No, most show no symptoms in the first 24 hours of life (EPISODIC).
These refer to the sequence of enzyme catalyzed reactions that lead to the conversion of a substance into a final product or excretable form.
Metabolic Pathways
Why are IEM symptoms often confused with other conditions?
They are episodic in nature of metabolic illness. The wide range of clinical symptoms that are associated with more common conditions like infection or sepsis).
Why is diagnosing IEMs challenging?
(A) Low incidence of these disorders.
(B) Lack of experience among pediatric subspecialties.
(C) Need for specialized testing.
What is required for substrate A to become substrate B?
An enzyme or pathway must act on substrate A.
What happens in IEMs regarding metabolic pathways?
There is a problem with the enzyme or hormone needed for metabolism, transformation, or catabolism.
What causes the interruption in the conversion of substrate A to B in IEMs?
A defect somewhere in the enzymatic chain or pathway.
Why is early detection of IEM important?
To identify affected babies before symptoms appear and prevent irreversible outcomes.
What are the goals of early detection in IEM?
(A) Quickly identify affected babies.
(B) Avoid missing cases.
(C) Minimize false-positive results.
(D) Early treatment can begin that prevents the negative and irreversible health outcomes for affected newborns.
What treatments are used for IEM?
These treatments are often inexpensive.
(A) Vitamin supplementation.
(B) Hormone supplementation.
(C) Avoidance of certain foods and chemicals.
(D) Dietary changes.
What technology is used for expanded newborn screening?
Tandem Mass Spectrometry (MS/MS).
How does Tandem Mass Spectrometry (MS/MS) work?
It separates and measures substances by their weight using a few drops of blood (MOLECULAR WEIGHT).
This type of congenital hypothyroidism pertains to the complete or partial absence of functional thyroid tissue or abnormal thyroid gland location.
Primary CH
This type of congenital hypothyroidism pertains to the defect in the brain areas responsible for stimulating thyroid hormone production, not the thyroid gland itself.
Secondary TH or Tertiary CH
What are the thyroid hormones?
(A) Tri-iodothyronine (T3).
(B) Thyroxine (T4).
Why is thyroxine or T4 important for newborns?
(A) Crucial for normal growth and development of the body and brain among newborns
(B) Excreted directly in the bloodstream
(C) Regulates temperature
This is a condition in which an individual does not produce enough thyroid hormone.
Congenital Hypothyroidism
What is the gland involved in congenital hypothyroidism?
Thyroid gland of the endocrine system
What causes Permanent Congenital Hypothyroidism (CH)?
(A) Defective thyroid gland development.
(B) Enzymatic defect in thyroxine synthesis.
(C) Pituitary dysfunction (rare).
What causes Transient Congenital Hypothyroidism (CH)?
Maternal intake of anti-thyroid medication or excess iodine.
What are the different clinical manifestations of congenital hypothyroidism?
(A) Hypotonia – Poor muscle tone.
(B) Prolonged jaundice – Due to immature liver conjugation of bilirubin, ↓ T4.
(C) Inactive defecation.
(D) Umbilical hernia.
(E) Pallor, coldness, and hypothermia – Due to ↓ T4.
(F) Edema and “rough” facial features.
(G) Enlarged tongue.
(H) Rough, dry skin.
(I) Open posterior fontanelles.
(J) Delayed overall development.