ADVANCED PATHOPHARMACOLOGICAL
FOUNDATIONS 2 KEY CONCEPTS AND REVIEW
NOTES 2026
◉ What causes ataxia in the pediatric population? Answer: - Genetic
predisposition
- Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS)
- Prader-Willie Syndrome
◉ What is Fragile X syndrome (FXS)? Answer: - A genetic condition
inherited from parents which results in various developmental
problems
- Rare, but may be dangerous or life-threatening
- Present at birth and is a lifelong condition
- Rarely requires lab testing or imaging
- Often linked to autism (1/3 do have autism)
- X-linked disorder
◉ Since Fragile X Syndrome (FXS) is an X-linked disorder, does a
specific gender have a greater risk? Answer: - Often, females are
carriers and males are affected
- However, both males and females can be carriers, and both can be
affected by the condition
,- Usually milder in females
◉ How did Fragile X Syndrome (FXS) get its name? Answer: - The
gene Fragile X (the FMR1 gene) is on the X syndrome
- Mutation of the FMR1 gene
◉ What is the difference between Fragile X-Associated
Tremor/Ataxia Syndrome (FXTAS) and Fragile X Syndrome (FXS)?
Answer: - Both caused by mutations on the FMR1 gene, but they are
caused by different changes in this gene
- FXS is caused by a full mutation
- FXTAS is a premutation
- FXS is present at birth, but display these features in early life
- FXTAS develops in adulthood (usually after age 50) and the
symptoms may appear slowly and develop over the years
- FXTAS individuals are usually healthy with normal cognitive skills
prior to the onset
◉ How is Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS)
diagnosed? Answer: - Being a FMR1 premutation carrier
- The appearance of neurological features such as ataxia (balance
problems), tremors, and other symptoms
- MRI findings (changes in the brain)
,◉ What is Prader-Willie Syndrome? Answer: - Genetic disorder that
affects many parts of the body and their growth
- Causes mental and behavioral problems
- Can be dangerous or life threatening if untreated
- Combination of contraceptives contraindicated in breast feeding
- More common in females
- Confirmed from laboratory findings
◉ What is the cause of Prader-Willi Syndrome? Answer: - Depletion
of chromosome 15 from father
- Missing or non-working genes on chromosome 15 (15q11-q13)
- Most cases are not inherited and occur randomly
- Depletion of genes (genes from the region are missing)
- Uniparental disomy - both chromosomes are inherited from the
mother
- Imprinting mutation - genes on the paternal chromosome is
inactive
◉ What does Prader-Willi Syndrome do to the body? Answer: -
Caused the hypothalamus to malfunction (the area of the brain that
affects hunger, thirst, sex and growth hormones)
- In infancy, an individual does not meet development milestones
suck as sitting up and walking
- Their eyes lack coordination
, ◉ What is a key feature of Prader-Willi Syndrome? Answer: - A
constant sense of hunger that usually begins around 2 years of age
- People with Prader-Willi Syndrome want to eat constantly because
they never feel full
◉ What are some symptoms in infants with Prader-Willi Syndrome?
Answer: - Hypotonia with floppy structure and poor muscle tone
- Distinct facial features affecting the shape and size of eyes, lips,
forehead, etc.
- Poor sucking ability making it difficult to feed
- Always lethargic and poor responsiveness
- Underdeveloped genitals
◉ What is celiac disease? Answer: - Autoimmune disease
- Damages to the small intestinal epithelium when there is ingestion
of gluten
- Loss of mucosal surface and brush border enzymes leads to severe
malabsorption that is more pronounced in the duodenum and
jejunum
◉ What strong genetic disposition does celiac disease have? Answer:
- Human leukocyte antigen DQ2 (HLA-DQ2) and HLA-DQ5
FOUNDATIONS 2 KEY CONCEPTS AND REVIEW
NOTES 2026
◉ What causes ataxia in the pediatric population? Answer: - Genetic
predisposition
- Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS)
- Prader-Willie Syndrome
◉ What is Fragile X syndrome (FXS)? Answer: - A genetic condition
inherited from parents which results in various developmental
problems
- Rare, but may be dangerous or life-threatening
- Present at birth and is a lifelong condition
- Rarely requires lab testing or imaging
- Often linked to autism (1/3 do have autism)
- X-linked disorder
◉ Since Fragile X Syndrome (FXS) is an X-linked disorder, does a
specific gender have a greater risk? Answer: - Often, females are
carriers and males are affected
- However, both males and females can be carriers, and both can be
affected by the condition
,- Usually milder in females
◉ How did Fragile X Syndrome (FXS) get its name? Answer: - The
gene Fragile X (the FMR1 gene) is on the X syndrome
- Mutation of the FMR1 gene
◉ What is the difference between Fragile X-Associated
Tremor/Ataxia Syndrome (FXTAS) and Fragile X Syndrome (FXS)?
Answer: - Both caused by mutations on the FMR1 gene, but they are
caused by different changes in this gene
- FXS is caused by a full mutation
- FXTAS is a premutation
- FXS is present at birth, but display these features in early life
- FXTAS develops in adulthood (usually after age 50) and the
symptoms may appear slowly and develop over the years
- FXTAS individuals are usually healthy with normal cognitive skills
prior to the onset
◉ How is Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS)
diagnosed? Answer: - Being a FMR1 premutation carrier
- The appearance of neurological features such as ataxia (balance
problems), tremors, and other symptoms
- MRI findings (changes in the brain)
,◉ What is Prader-Willie Syndrome? Answer: - Genetic disorder that
affects many parts of the body and their growth
- Causes mental and behavioral problems
- Can be dangerous or life threatening if untreated
- Combination of contraceptives contraindicated in breast feeding
- More common in females
- Confirmed from laboratory findings
◉ What is the cause of Prader-Willi Syndrome? Answer: - Depletion
of chromosome 15 from father
- Missing or non-working genes on chromosome 15 (15q11-q13)
- Most cases are not inherited and occur randomly
- Depletion of genes (genes from the region are missing)
- Uniparental disomy - both chromosomes are inherited from the
mother
- Imprinting mutation - genes on the paternal chromosome is
inactive
◉ What does Prader-Willi Syndrome do to the body? Answer: -
Caused the hypothalamus to malfunction (the area of the brain that
affects hunger, thirst, sex and growth hormones)
- In infancy, an individual does not meet development milestones
suck as sitting up and walking
- Their eyes lack coordination
, ◉ What is a key feature of Prader-Willi Syndrome? Answer: - A
constant sense of hunger that usually begins around 2 years of age
- People with Prader-Willi Syndrome want to eat constantly because
they never feel full
◉ What are some symptoms in infants with Prader-Willi Syndrome?
Answer: - Hypotonia with floppy structure and poor muscle tone
- Distinct facial features affecting the shape and size of eyes, lips,
forehead, etc.
- Poor sucking ability making it difficult to feed
- Always lethargic and poor responsiveness
- Underdeveloped genitals
◉ What is celiac disease? Answer: - Autoimmune disease
- Damages to the small intestinal epithelium when there is ingestion
of gluten
- Loss of mucosal surface and brush border enzymes leads to severe
malabsorption that is more pronounced in the duodenum and
jejunum
◉ What strong genetic disposition does celiac disease have? Answer:
- Human leukocyte antigen DQ2 (HLA-DQ2) and HLA-DQ5
