Genetic Disorders

Question 1

Knowledge About Genetic Disorders Enables the Physical Therapist to:

Answer 1

• Participate in the diagnostic process
• Discuss the disorder with the family
• Provide appropriate intervention

Question 2

4 Types of Genetic Disorders

Answer 2

• Chromosome Disorders
• Single-Gene Disorders
• Multifactorial Disorders
• Mitochondrial Disorders

Question 3

2 different types of chromosome disorders

Answer 3

1. Numerical Abnormalities
2. Structural Abnormalities

Question 4

Numerical abnormalities

Answer 4

• Entire chromosome is missing or extra chromosome is present
• Examples: Down syndrome, Klinefelter syndrome, Turner syndrome

Question 5

Structural Abnormalities

Answer 5

• Involve deletion, translocation, inversion, duplication, or other rearrangement of chromosomes
• Ex: Prader- WIlli, Cri-Du-Chat, Wolf-Hirschhorn

Question 6

Single Gene Disorders

Answer 6

• Autosomal dominant – single gene mutated or abnormal
• Autosomal recessive – result when the same abnormal
  allele is inherited from each parent

Question 7

X linked recessive inheritance

Answer 7

males are affected
females are carriers

Question 8

Multifactorial disorders/ complex disease

Answer 8

-result from a combination of genetic and environmental factors
- Cleft Palate, spina bifida, heart disease, diabetes

Question 9

Mitochondrial Disorders

Answer 9

result due to alterations of small mitochondrial DNA fragments that are typically inherited from the mother

Question 10

Newborn Genetic Screenings

Answer 10

• States in the US routinely screen newborns for
  certain genetic, metabolic, hormonal, and functional disorders
• Each state regulates which screening tests are given to babies

Question 11

Some examples of conditions that IL screens for

Answer 11

PKU
Thyroid disease
Hearing loss
Congenital Heart Disease

Question 12

Is genetic screening done as a child or an adult?

Answer 12

either!

Question 13

when is genetic screening used?

Answer 13

• Has no signs or symptoms
• Has no clinically significant family history
• Belongs to a certain population (such as a racial or ethnic group) that may be at greater risk for certain disorders or traits
• Does not provide diagnosis

Question 14

When is genetic testing done?

Answer 14

• Clinically significant signs and/or symptoms
• A clinically significant family history
• Positive genetic screen results
• Provides a diagnosis or prediction of a genetic condition

Question 15

Role of PT in diagnostic process

Answer 15

• Exam and Eval (medical history and red flags)
• Genetic Counseling
• Resource for information, referrals, education

Question 16

Red Flags for the infant/child (its a lot!)

Answer 16

• Down Syndrome or other chromosome abnormality.
• Birth defects
• Blindness/vision loss
• Deafness/hearing loss
• Chronic or sig. skin prob.
• Bleeding disorders
• Extremely tall or short stature
• An excess of broken bones
• Muscle weakness or inability to walk
• MR, DD, LD
• Speech problems
• Attention deficit/hyperactivity
• Seizures
• Miscarriages/infertility
• Consanguinity
• Specific genetic cond.
• Dysmorphic features
• Loss of milestones
• Unexplained hypotonia or hypertonia
• Ataxia or other mvt. Disorder
• Ethnicity
• Failure to thrive
• Recurrent infections
• Sleep disorders
• Allergies
• Obesity

Question 17

Life Expectancy of Down syndrome

Answer 17

60 years old

Question 18

Progression issues of Down syndrome

Answer 18

• Impact of hypotonia and underlying weakness
• Impact of growth on the developing MSK system
• Impact of cognitive impairment on development
• Impact of additional conditions such as fluid in ears; thyroid disease; Alzheimer’s Disease

Question 19

Down syndrome

Answer 19

• Large tongue
• hypotonia
• cognitive delay
• epicanthal fold in eyes/characteristic eyes
• congenital heart disease
• intestinal defect
• simian crease
• shortened 5th finger
• wide gap between first and second toes

Question 20

Prader-Willi

Answer 20

• Almond shaped eyes and poor eye sight
• R sided heart failure
• High blood pressure
• Speech deficit - SLP
• hypotonic
• Life expectancy: into adulthood
• Obesity - cannot control their appetite
  ◦ At risk for DMII

Question 21

Cri-du-Chat

Answer 21

• Early on: microcephaly (very significant) and low birth weight
• Limiting lifespan: heart condition; lifespan is improving can live to > 50yo
• Hypotonia
• ADHD
• Loud high pitched cry
• developmental delays limiting independence
• Present similar to CP; GMFCS IV or V
• Pretty much need all referral systems

Question 22

PKU- Metabolic Disorder

Answer 22

• Can’t break down foods
  ◦ Need dietician
• Microcephaly
• Delayed development
• Musky odor in breath and urine
  ◦ Hard time going to school
  ◦ Part of education on how to manage this
• Can be in regular ed but also might need special ed… large variability

Question 23

Neurofibromatosis

Answer 23

• NF1: found below 18 yo
  ◦ Integument changes
• NF2: found between 18-20 something
  ◦ Vestibular component
• Cognitively intact
  ◦ maybe learning disorder or ADHD
• Noncancerous tumor
  ◦ spots on the skin - can look like abuse
• Don’t see this at birth
• Treat what you see
• Biggest referral: neurologist

Question 24

Fragile X

Answer 24

• More common
• Age of diagnosis: 3 years for males, 42 mo for females
  ◦ start to see symptoms at 12 mo
• not typically progressive
• long ears, face, jaw
• microcephaly
• sensitive to bright light and loud noises –> plan your environment
• susceptible to MVP
• Hypotonia and lack of joint stability
• sometimes misdiagnosed as FAS

Question 25

Mitochondrial Disease

Answer 25

* Take a good health screen * This is "diseases" because it is dealing more with the medical components of what is going on in the body ◦ organ failure, changes in medical status, etc

Question 26

Achondroplasia

Answer 26

* Autosomal Dominant: Don't need both parents to have it; only need a single gene * Very Rare * Large Head, Frontal bossing, decreased growth in midface * Abnormal bone growth, short, short UEs and LEs * Frequent ear infections * Obesity * Hypotonia in infancy * Risk for airway obstruction * No cognitive delay * Large head will make it very difficult for them to develop head righting and neck extension ◦ Head can pull them down and disturb COM --> at risk for TBI due to balance problems * Environmental Considerations ◦ school bus step taller than them