Genetic Disorders Chapter 8
Musculoskeletal problems to be associated with Cri_du_Chat include
-Clubfeet -Hip Dislocation -Joint Hypermobility -Scoliosis *LOW muscle tone= musculoskeletal alignment problems may occur
Describe a child's movements with Cri-Du-chat
Laborious and inconsistent *gravity is an enemy *postural control is difficult because of the low tone
This is a wearable exoskeleton that assists a child to lift the arms and encourages reaching behavior
Playskin lift
Define behavioral phenotype
Profile of behavior, cognition, or personality that represents a component of the overall pattern seen in many or most individuals with a particular condition or syndrome
In type 1 SMA, motor weakness progresses ____ and death results from respiratory compromise within the first __ years of life
Progresses rapidly ; 2 years
What is the prestage of Rett Syndrome and when does it decline
The child's development appears normal and this is the prestage that lasts 6 months -Followed by 4 stages of decline
What are the general characteristics of someone with OI
-"brittle bones" -Short Stature -Bowing of Long Bones -Ligamentous joint laxity -Kyphosis -Scoliosis
Surgical procedures that have been used to combat the progressive effects of DMD are
-Achilles Tendon Lengthening -TFL Fasciotomy -Tendon Transfers -Tenotomies
What does exercise improve in CF patients
-Airway clearance -Delays decline in pulmonary function -Delays onset of Dyspnea -Prevents decrease in bone density
A specific gene defect is inherited in what 3 different ways
-Autosomal Dominant Trait -Autosomal recessive trait -Sex linked trait; abnormal gene is carried on the X Chromsomes
Examples of autosomal recessive disorders
-CF -Phenylketonuria -3 types of SMA *SMA - most people died; typically 2 years
a child with AMC has what 2 major goals for PT
-Functional movement -Maintenance of ROM *stretching 3-5X a day and held for 20-30 sec at the end of range
What systems does CF involve
-Gastrointestinal -Reproductive -Sweat Glands -Respiratory
What are the symptoms of AAI
-Hyperreflexia -Clonus -Babinskis sign -Torticollis -increased loss of strength -Sensory changes -Loss of bowel or bladder -Decrease in motor skills
Children with SMA exhibit what
-Hypotonia of peripheral -Weakness -Normal intelligence
What are the cohen facial features
-Hypotonic appearance -Thick hair and eyebrows -Long eyelashes -Smooth or short philtrum -Broad nasal tip -wave shaped palpebral fissures
List the characteristics of a child with down syndrome
-Hypotonicity -Joint Hypermobility -Upwardly slanting epicanthal folds -Flat nasal bridge and facial profile *small oral cavity that makes the tongue seem protruded
Interventions with children who have PWS/AS should be directed toward
-Increasing muscle strength -Aerobic Endurance -Postural Control -Movement efficiency -function -respiration to manage obesity and minimize cardiovascular risk factors and osteoporosis
What are clinical characteristics of Cri-Du-Chat
-Microcephaly; diagnosed when the head circumference is less than third percentile -Widely spaced eyes -Profound ID *Cat cry is only present in infancy and the result of laryngeal malformation
What 2 causes can fetal akinesia have
-Myopathic -Neuropathic
Visual impairments in children with DS include
-Nearsightedness (myopia) -Cataracts -Crossing of the eyes (Esotropia) -Nystagmus -Astigmatisim
Features of PWS
-Obesity -Underdeveloped gonads -Short Stature -Hypotonia -mild to moderate ID *Become obsessed with food at 2 years old = hyperphagia
What are some musculoskeletal manifestations that may occur in those with DS
-Pes Planus -Thoracolumbar scoliosis -Patellar Dislocation -Possible atlantoaxial instability (AAI)
Features of AS
-Significantly delayed development -ID -Ataxia -Severe Speech Problems -Progressive Microcephaly *delays not apparent until 6-12 months
How are PT needs determined in children with SMA
-Specific type of SMA -Functional limitations -age of the child
key muscles to target in children with DMD if exercise is going to be used to treat weakness includes
-The abdominals -Hip Extensors / abductors -Knee Extensors *Triceps and Scap Stabilizers in the UE
How do you diagnose Cohens Syndrome
-basis of molecular genetic testing and the presence of 6 of the 8 cardinal features: -Retinal dystrophy & High Myopia -Microcephaly -Developmental delay -joint hypermobility -typical cohen syndrome facial features -Truncal obesity with slender extremities -Overly sociable behaviors -Neutropenia
Fragile X connective tissue involvement can include ?
-joint hypermobility -flat feed (pes planus) -Inguinal hernia -Pectus excavatum -mitral valve prolapse
What makes BMD different from DMD
-later onset -slower progression with longer life expectancy -less elevation of creatine kinase levels -Less destruction of muscle fibers on biopsy -Lower incidence of ID
Behavior characteristics of FXS include
-short attention -impulsivity -tactile defensiveness -hyperactivity -preservation in speech and motor action
Strengthening what specific muscles in the upper body can assist with respiration
-shoulder girdle -Chest Wall Muscles: -Pec Major/Minor -intercostals -Serratus -Erector Spinae -Rhomboids -Latissimus Dorsi -Abdominals
Chromosome abnormalities include
-trisomies; 3 of a particular chromosome are present instead of the usual 2 -sex chromosome abnormalities; there is an absence or addition of one sex chromosome -partial deletions; PWS and cri-du-chat
What are the first 4 types of classification scheme for OI ; they are all inherited as an autosomal dominant trait
1 - Mild to moderate fragility; Mildest; Community ambulation 2- In uterine fx; Most Severe (perinatal lethal); Nonambulation 3-Progressive Deformities; Moderately severe; Exercise Walking 4-Mild to moderate deformity, short stature; more severe than 1; Household/Community Ambulation
What is the % of the population of the US that has psychomotor or ID
1-3%
In children with AMC when is ambulation typically achieved
18 months *any surgery's that need to occur should after the child is stronger and wants to walk around 12 months
The standing goal for a 1 year old child is how long a day
2 hours
how long should walking be done in a child with DMD
2-3 hours a day
List autosomes, chromosomes, sex chromosome, and reproductive cells
22 - autosomes 44 - chromosomes 2 - sex chromosomes *reproductive cells contain 23 chromosomes (22 auto and 1 X/Y Chromosome)
How long does it take to elicit behavioral changes in habitual physical activity
6 months or more
Life expectancy of those with DS
60 years *15-20% higher chance of acquiring leukemia in their first 3 yrs of life *Live past 40 yrs develops pathological sings of Alzheimer's *Live past 65 yrs have signs of dementia
To be diagnosed with an ID the IQ must be
70-75 or below *DS children range 25-50
Defined by the presence of contractures in two or more body areas; is a nonprogressive neuromuscular syndrome *The gene that cases the neuropathic form is found on chromosome 5; distal for hands and feet is 9
AMC - arthrogryposis multiplex congenita *not all cases have a genetic origin
In a full blown mutation of Fragile X Syndrome how much FMRP is produced
Almost none *The less FMRP produced the more severe the ID is
FXS is the most common single gene defect associated with what other disorder
Autism Spectrum Disorder
How is CF diagnosed
Basis of a positive sweat chloride test >> than 60mEq/L indicate CF
This disorder has an onset of symptoms between 5 and 10 years of age ; is an X-linked dystrophy and is the milder form of DMD
Becker Muscular dystrophy - BMD
This is an autosomal recessive disorder of the exocrine glands that is caused by a defect on chromosome 7 -Is the most lethal genetic disease in white patients
CF- Cystic Fibrosis *New born screening mandated in every state
This is a rare autosomal recessive cause of hypotonia in children
Cohen Syndrome
Elevated levels of what are often found in the blood as a result of the breakdown of muscle in those with DMD
Creatine Kinase *measure of the amount of muscle fiber loss ; Made by a muscle biopsy
This syndrome is the result of the short arm of chromosome 5 being deleted
Cri-Du-Chat "Cat Cry" *affects the nervous system resulting in ID
This syndrome has children who exhibit the result of intrauterine growth retardation by being small for their gestational age
Cru-Di-Chat
This is an X-linked recessive trait that is manifested only in boys -2/3 of these cases are inherited where 1/3 results from spontaneous mutation
DMD - Duchenne Muscular Dystrophy
Most common examples of X-Linked recessive disorders
DMD and hemophilia *FXS is the most common that causes ID in males *Rett syndrome in females
What are some developmental findings in those with DS
Delayed development and impaired motor control *feeding problems may be evident at birth and may require intervention
This is the best way to stabilize fractures that occur in the long weight bearing bones in children with OI
Intramedullary Rod Fixation
SMA type 1 infants rely on what to help them breathe
Diaphragm because their intercostals and neck accessory muscles are weak
This is the leading chromosomal cause of ID and the most frequently reported birth defect
Down syndrome *caused by a genetic imbalance resulting in the presence of an extra 21st chromosome or trisomy 21 in al or most of the body's cells
What should the water temp be set at when doing pool exercises with an OI child
Kept low because of the child's increased metabolism *sessions last only 20-30 minutes
What trimester of pregnancy has been identified as the most likely time for the primary insult to occur that produces AMC
First
This is the leading inherited cause of ID and is characterized by unusual fancies, poor coordination, a generalized decrease in muscle tone, and enlarged testes in male patients after puberty *Children may have a long narrow face with a prominent forehead, jaw, and ears
Fragile X Syndrome
What is chromosomal microarray analysis (CMA) used to discover
Genetic Causes of: -ID -Autism spectrum disorder -Developmental Delay -Multiple Congenital Anomalies
What's the difference between girls and boys with Fragile X syndrome
Girls do not typically present with dysmorphic features (often seen in the face) or connective tissue abnormalities *more likely to have normal intelligence but may have a learning disability
How is Rett syndrome characterized
ID -Ataxia -Growth Retardation *presents a failure of postnatal development caused by a mutation in the MECP2 gene
Failure to keep the body weight __ of the knee joint or ___ the hip joint results in a loss of the ability to stand
In front of the knee; behind the hip
Children with knee ____contractures tend to require less orthotic control than those with knee ____ contractures
Knee extension ; knee flexion
Diffuse Osteoporosis results in
Multiple recurring fractures, weak muscles, joint laxity, and spinal/long bone deformities
AMC pathogenesis has been related to what 3 abnormalities associated with intrauterine movement restriction, but still has no exact known cause
Muscular, Nervous, Joint
The lack of this protein in DMD children prevents proper alignment of the contractile filaments during muscle contraction
Nebulin
What 2 systems are derived from the same primitive tissue
Nervous and Integumentary ; they are embryonically linked
How long does postural drainage treatment last
No more than 30 minutes
This is the first drug for SMA and was introduced in 2016
Nusinersen *designed to increase the amount of functional survival motor neuron protein
PWS is the most common genetic form of
Obesity
How do chromosomal abnormalities occur
One of the three ways -nondisjunction; cells divide unequally can cause DS -Deletion; part or all a chromosome is lost -Translocation; part of a chromosome becomes detached and reattaches to a completely different chromosome
This is an inherited connective tissue disorder secondary to a defect in collagen synethsis
Osteogenesis Imperfecta - OI
One genetic cause of ID that is preventable is the inborn error of metabolism called... -caused by an autosomal recessive trait that can be detected at birth by a simple blood test
PKU - Phenylketonuria
This syndrome is caused by a partial deletion of a chromosome; microdeletion of part of the long arm of chromosome 15
PWS = Prader Willi Syndrome / Angelman Syndrome *PWS = DAD *AD = MOM *more common than cri-du-chat
This is a powerful antiresorptive agent and has become the standard of care for children with moderate to severe OI
Pamidronate = a biophosphonate *studies done shows it helps increase bone density , decrease bone pain, and increase the ability of patients to ambulate
Death in those with BMD comes from
Pulmonary or cardiac failure *DMD is respiratory
How should ROM be performed in children with OI
ROM in a straight plane with emphasis placed on the shoulder and pelvic girdles
What is the main cause of death in children with SMA
Respiratory compromise
This is a neurodevelopmental disorder that almost exclusively affects females Does not progress
Rett syndrome
This is a progressive disease of the nervous system inherited as an autosomal recessive trait The anteriorhorn cell undergoes progressive degeneration
SMA - Spinal Muscular Atrophy
This type of SMA has a later onset of 6-12 months and is characterized by the onset of proximal weakness
SMA type 2
SMA is the ___most common fatal recessive genetic disorder seen in children after CF, and the ___ genetic cause of early death in infants and toddlers
Second most common ; leading genetic
Hearing loss in children with DS can occur
Sensorineural loss = 8th cranial nerve is damaged conductive loss = too much fluid in the middle ear; may cause delayed language development
Proximal muscle weakness is one of the major clinical features of DMD and is the most clearly apparent in what body structures
Shoulder and Pelvic girdles
Where should an assistant or caregiver provide manual assistance to help encourage head lifting and trunk activation when the assistant is helping the child into an upright position
Shoulders *traditional pull to sit maneuver is contraindicated
what happens at the ages of 3-5 in those with DMD
The child may begin to fall more often or experience difficulty in going up and down stairs *Gower Maneuver to move into a standing position from the floor
What are examples of sex chromosome errors
Turner syndrome and Klinefelter syndrome
What two types of OI would a PTA most likely treat? They are also the most common
Type 1 and 4
The earliest occurring and the most physical devastating form of SMA.
Type 1, acute infantile SMA *frog legged LE posture is evident at birth along with a weak cry
This type of SMA has an onset between 1-10 years and is the most mild Characteristics include proximal weakness in the hips, knees, and trunk
Type 3 SMA
What helps differentiate SMA type 3 from DMD
Type 3 SMA children have good UE strength
How is PWS/AS diagnosed
by the child's behavior and physical features ; confirmed by genetic testing
children with DMD lack the gene that produces the muscle protein ___ ; smooth muscle is also affected by the lack of this
dystrophin *absence of this protein weakens the cell membrane and eventually leads to the destruction of muscle fibers
