Module 4 case study
QUESTION 1
Jordan is now 19-years old. As an infant, Jordan reached many gross motor skill
milestones, such as holding his head up, rolling over, sitting, and standing, at normal
times. However, he was considered a “late walker” because he took his first steps at
17 months. By 2 years old, his parents noticed a hyperlordotic posture while he was
standing. A Gower's sign and Trendelenberg gait were noted by age four.
Throughout his childhood, he suffered progressive muscle weakness, especially in
the proximal musculature of the arms, pelvis, and legs. He required orthotic braces
to assist his walking and was confined to wheelchair ambulation by age 13.
At 16, he was hospitalized with bronchitis requiring antibiotic treatment, but
recovered. Jordan has a history of progressive muscle weakness, but no history of
muscle pain or spasm, chest pain, or irregular heartbeat. The only medications that
he normally takes are calcium and fluoride supplements. Jordan has three siblings.
His older and younger sisters have never had any major medical issues. Jordan’s
older brother is also to a wheelchair with problems similar to Jordan's. No other
immediate or distant family members have musculoskeletal issues.
Jordan’s history aligns most closely with which diagnosis?
Multiple sclerosis
Amyotrophic lateral sclerosis
Myotonic dystrophy
Duchenne muscular dystrophy
QUESTION 2
Jordan had a biopsy of the left gastrocnemius muscle when he was 5 years
old. Based on your answer for his diagnosis, describe the microscopic
pathological changes that the pathologist would have noted in her report.
The pathologist would note changes in the skeletal muscle fibers, a lack of dystrophin
which is the protein that holds muscle cells together. The pathologist would also note
the rapid growth of connective tissue around the decline of muscle fibers (Journal of
Neurology, Neurosurgery, and Psychiatry, 1972).
Reference
https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC494103&blobtype=pdf
, QUESTION 3
Explain, in your own words, why Jordan’s brother appears to have the same
disease and why his sisters are unaffected.
Duchenne muscular dystrophy (DMD) is most common in males due to males having only one
X chromosome. If their only X chromosome has the DMD trait then they will have DMD because
they do not have a backup X chromosome (National Human Genome Research Institute, 2013).
For females DMD is not as common but females are normally the carriers for the DMD trait.
DMD is not common in females due to them having two X chromosomes so if one X
chromosome is affected by the DMD trait than the second X chromosome acts as a backup in
releasing dystrophin protein (National Human Genome Research Institute, 2013).
Reference
https://www.genome.gov/Genetic-Disorders/Duchenne-Muscular-Dystrophy
QUESTION 4
Jordan’s calves appear enlarged. Which of the following statements
explains this phenomenon?
As his muscles degenerate, the muscle tissue is replaced by collagen and adipose tissue.
As Jordan ages, the neuromuscular junction loses its neurotransmitters.
Jordan’s muscle cells are experiencing calcification because the actin and myosin
filaments are no longer able to release from each other.
As his muscle degenerate, calcium replaces the water in the muscle cells.
QUESTION 5
Jordan displayed Gower’s sign at a young age. Which of the following
statements explains why this this true?
The weakness of his proximal leg muscles and erector spinae muscles force Jordan
to use his arms to push on the floor.
His neuromuscular junctions were interrupting the signals to contract his muscles.
Jordan’s quadriceps and gluteus maximus are in spasm, which causes him to fall to
his knees when trying to stand.
The chronic contractures in Jordan’s lower legs cause him to be reliant on his upper
body for strength.
QUESTION 1
Jordan is now 19-years old. As an infant, Jordan reached many gross motor skill
milestones, such as holding his head up, rolling over, sitting, and standing, at normal
times. However, he was considered a “late walker” because he took his first steps at
17 months. By 2 years old, his parents noticed a hyperlordotic posture while he was
standing. A Gower's sign and Trendelenberg gait were noted by age four.
Throughout his childhood, he suffered progressive muscle weakness, especially in
the proximal musculature of the arms, pelvis, and legs. He required orthotic braces
to assist his walking and was confined to wheelchair ambulation by age 13.
At 16, he was hospitalized with bronchitis requiring antibiotic treatment, but
recovered. Jordan has a history of progressive muscle weakness, but no history of
muscle pain or spasm, chest pain, or irregular heartbeat. The only medications that
he normally takes are calcium and fluoride supplements. Jordan has three siblings.
His older and younger sisters have never had any major medical issues. Jordan’s
older brother is also to a wheelchair with problems similar to Jordan's. No other
immediate or distant family members have musculoskeletal issues.
Jordan’s history aligns most closely with which diagnosis?
Multiple sclerosis
Amyotrophic lateral sclerosis
Myotonic dystrophy
Duchenne muscular dystrophy
QUESTION 2
Jordan had a biopsy of the left gastrocnemius muscle when he was 5 years
old. Based on your answer for his diagnosis, describe the microscopic
pathological changes that the pathologist would have noted in her report.
The pathologist would note changes in the skeletal muscle fibers, a lack of dystrophin
which is the protein that holds muscle cells together. The pathologist would also note
the rapid growth of connective tissue around the decline of muscle fibers (Journal of
Neurology, Neurosurgery, and Psychiatry, 1972).
Reference
https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC494103&blobtype=pdf
, QUESTION 3
Explain, in your own words, why Jordan’s brother appears to have the same
disease and why his sisters are unaffected.
Duchenne muscular dystrophy (DMD) is most common in males due to males having only one
X chromosome. If their only X chromosome has the DMD trait then they will have DMD because
they do not have a backup X chromosome (National Human Genome Research Institute, 2013).
For females DMD is not as common but females are normally the carriers for the DMD trait.
DMD is not common in females due to them having two X chromosomes so if one X
chromosome is affected by the DMD trait than the second X chromosome acts as a backup in
releasing dystrophin protein (National Human Genome Research Institute, 2013).
Reference
https://www.genome.gov/Genetic-Disorders/Duchenne-Muscular-Dystrophy
QUESTION 4
Jordan’s calves appear enlarged. Which of the following statements
explains this phenomenon?
As his muscles degenerate, the muscle tissue is replaced by collagen and adipose tissue.
As Jordan ages, the neuromuscular junction loses its neurotransmitters.
Jordan’s muscle cells are experiencing calcification because the actin and myosin
filaments are no longer able to release from each other.
As his muscle degenerate, calcium replaces the water in the muscle cells.
QUESTION 5
Jordan displayed Gower’s sign at a young age. Which of the following
statements explains why this this true?
The weakness of his proximal leg muscles and erector spinae muscles force Jordan
to use his arms to push on the floor.
His neuromuscular junctions were interrupting the signals to contract his muscles.
Jordan’s quadriceps and gluteus maximus are in spasm, which causes him to fall to
his knees when trying to stand.
The chronic contractures in Jordan’s lower legs cause him to be reliant on his upper
body for strength.
