Lecture 17: Genetic and Developmental Disorders

Question 1

Study of Heridity

Answer 1

• transmitted through genes in gametes (eggs or ova and sperm)
• genetic make-up is determined at fertilization
• in nucleus of each gamete are structures called chromosomes
• each chromosome contains a strand of DNA (made up of genes)

Question 2

Counting Chromosomes

Answer 2

-ovum and sperm each contain 23 chromosomes and, when united, they pair up
-the fertilized cell has 23 pairs or 46 chromosomes and undergoes cell division (mitosis): each of the 46 chromosomes produces an exact duplicate, cell then divides and each new cell receives one set of the 46 chromosomes…this repeats itself over and over, so, each cell in a person’s body contains 46 identical
chromosomes…except the ova and sperm
-each person receives one set of chromosomes and genes from each parent-so, there are 2 genes for each trait that person inherits and one gene may be more influential (dominant) than the other (recessive) in
developing a specific trait
-locus=location of a gene on a chromosome very specific and does not vary from person to person
-of the 23 pairs, 22 pairs are not involved in controlling a person’s gender called autosomes, 2 sex chromosomes of the 23rd pair determine gender
-gene mutations may be transmitted during reproduction and may cause serious or deadly disorders

Question 3

Alleles

Answer 3

• variation of a gene and the trait it controls (brown, green or blue eye color) is called an allele
• when 2 different alleles are inherited=heterozygous
• when 2 identical alleles are inherited=homozygous
• if an allele is dominant, only 1 copy may be necessary for trait expression (may be expressed in both homozygous and heterozygous states)
• recessive allele is incapable of expression unless recessive alleles are carried by both chromosomes in a pair

Question 4

Single-Gene Disorders: Autosomal Dominant

Answer 4

• disorders are inherited in clearly identifiable patterns
• male and female offspring affected equally
• one of the parents also usually affected
• if one parent is affected, the children have a 50% chance of being affected
• if both parents are affected, all of the children will be affected

Question 5

Single-Gene Disorders: Autosomal Recessive

Answer 5

• male and female offspring affected equally
• if both parents unaffected, but heterozygous for the trait (carriers), each of the children has a 1 in 4 chance of being affected
• if both parents affected, all children affected
• one parent is affected and the other is not a carrier, all of the children will be unaffected, but will carry the altered gene
• one parent is affected and the other is a carrier, all of the children will have a 1 in 2 chance of being affected and a 1 in 2 chance of being a carrier
• certain autosomal recessive conditions are more common in specific ethnic groups (cystic fibrosis in white people and sickle cell anemia in black people)

Question 6

Single-Gene Disorders: Sex-Linked Inheritance

Answer 6

• disorders caused by genes located on the sex chromosomes (usually refers to X-linked disorders
• males are more commonly affected by X-linked disorders, since they have only one X chromosome
• in comparison, females need two copies of the diseased gene to be affected

Question 7

Single-Gene Disorders: Sex-Linked Inheritance- X-Linked Dominant

Answer 7

• person with the abnormal trait will typically have 1 affected parent
• father has an X-linked dominant disorder, all of his daughters and none of this sons will be affected (can only pass Y, no X
• mother has an X-linked dominant disorder, there is a 50% chance that each child will be affected
  d. Evidence of the inherited trait most commonly appears in the family history
• X-linked dominant disorders are commonly lethal in males (prenatal or neonatal deaths): family history may show miscarriages or predominance of female offspring

Question 8

Single-Gene Disorders: Sex-Linked Inheritance-X-Linked Recessive

Answer 8

• most cases, affected people are males with unaffected parents
• all of the daughters of an affected male will be carriers
• sons of an affected male are unaffected (unaffected sons can’t transmit the disorder)
• unaffected male children of a female carrier don’t transmit the disorder

Question 9

Chromosomal Disorders

Answer 9

• disorders caused by chromosomal aberrations
• nondisjunction: normally there is a separation of chromosomes during cell division, but if distribution is unequal between two cells it’s called nondisjunction
• monosomy: cell that’s missing a chromosome (Turner Syndrome)
• trisomy: a cell that contains an extra chromosome (Down Syndrome)
• incidence increases with parental age
• translocation: two different chromosomes break and rejoin in abnormal arrangement (abnormalities may present in 2nd generation)

Question 10

Multifactorial Disorders

Answer 10

• disorders caused by both genetic and environmental factors

- ex: cleft lip, cleft palate, myelomeningocele

Question 11

Cleft Lip and Cleft Palate

Answer 11

• malformations occur in ~1/800 births
• cleft lip with or without cleft palate is more common in males and cleft palate alone is more common in females
• multifactorial genetic disorder and originates in the 2nd month of gestation
• malformations fall into 4 categories: cleft lip, unilateral cleft lip and cleft palate, bilateral cleft lip and cleft palate, cleft palate
• malformations may range from a simple notch to a complete cleft, structural changes can permanently affect speech
• dx: may be detected prenatally using US
• tx: combo of speech therapy and sx

Question 12

Cystic Fibrosis

Answer 12

• inherited autosomal recessive trait disorder of ion transport (Na+ and Cl-) affecting the hepatic, digestive, male reproductive, and respiratory systems
• incidence is highest in Whites of Northern Europe (1/3,300) and less common in black people, Native Americans, and asians people
• mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene located on chromosome 7
• patho: mutation results in a protein that doesn’t function properly (lacks phenylalanine…an essential amino acid)
• lack of an essential amino acid leads to dehydration and mucosal thickening
• salt accumulates in the cells lining the lungs and digestive tissues, making the surrounding mucus abnormally thick and sticky
• CM: abnormally high sodium and calcium concentrations in sweat; gastrointestinal: prevents essential pancreatic enzymes from reaching the duodenum, thus impairing digestion and absorption of nutrients; poor nutrition and weight loss as a result of malabsorption, inadequate oral intake, early satiety, and ↑’d utilization of calories; diabetes and pancreatitis may result; hepatic failure and cholecystitis
• pulmonary: chronic cough and purulent sputum production, unable to expectorate mucus because of increased viscosity, increased risk for infection, frequent bouts of pneumonia, dyspnea
• genitourinary: infertility is universal in me (azoospermia-no sperm in semen), thick mucus in cervical canal prevents conception (mucus plug)
• musculoskeletal: decreased bone mineral density and bone mineral content are common
• predisposes one to chronic bacterial airway infections leading to obstructive lung disease and progression can result in loss of pulmonary function

Question 13

SIFTT for Cystic Fibrosis

Answer 13

• chest PT: several times a day but not before or immediately after meals
• nutrition: malnutrition and deterioration of lung function are closely interrelated and interdependent in child with CF
• exercise: supervised exercise programs enhance fitness, increases sputum clearance, delay onset of dyspnea, delay declines in pulmonary function
• athletes with CF: eat 1.5 times of protein and calories of an athlete who does not have CF in order to maintain weight, individuals who have portal HTN with significant enlargement of the spleen and liver should be advised against contact sports

Question 14

Down Syndrome

Answer 14

-trisomy 21, characterized by muscle hypotonia, cognitive delay, abnormal facial features, heart defects, and other congenital disorders
-most common inherited chromosome disorder, 1/800-1000 live births
-incidence rises with maternal age: before maternal age 30 the incidence is 1 in 2000 births; 1 in 50 for
mothers aged 35-39, and 1 in 12-20 in mothers over 40; women over age 35 bear 20% of all children with Down syndrome
-produces 3 copies of chromosome 21 instead of the normal 2 because of faulty meiosis (cell division by which reproductive cells are formed) of the ovum or sometimes the sperm
-can also occur after fertilization leading to only a portion of cells being affected with a milder clinical picture
-incidence of nondisjunction ↑’s with maternal age with the extra chromosome originating from the mother more than 90% of the time: 5-10% of Down’s syndrome is correlated to paternal age
-overall reduction in brain weight
-CM: flattened nasal bridges, almond eye shape, short limbs, short broad hands/feet and mild to moderate hypotonia
-many other associated clinical manifestations may also be present: flat occiput, joint hyperextensibility, epicanthal folds, high arched palate; protruding, fissured tongue, CHD, simian line (transverse
palmar crease)
-variety of musculoskeletal or orthopaedic problems believed to be acquired secondary to soft tissue laxity and muscle hypotonia
-common findings include recurrent patellar dislocation, excessive foot pronation, scoliosis, slipped capital femoral epiphyses, late hip dislocation (after 2 years)
-atlantoaxial instability (AAI) of the c/spine (subluxation between C1 and C2) odontoid process can slide back into spinal column leading to death
-feeding difficulties and delayed acquisition of motor skills: these skills, however, improve with age, these children present with slower reaction times and slower postural reactions
-gait abnormalities
-secondary disorders develop after age 30 or 35
-obesity, DM, cardiovascular disease
-dx: triple screen (screen for alpha fetal protein AFP) allows detection of an estimated 60-70% of fetuses with down syndrome; prenatal diagnosis may be made during 2nd trimester
-prognosis: presence of congenital malformations, especially of heart, GI tract, can result in high mortality rates in affected population; mobility and eating skills are also predictors of early death
-SIFTT: because AAI is a problem, radiographs should be considered before any type of event that could result in a direct downward force on the cervical area (need to be sure odontoid is at risk of sliding backward in any act that involves movement)

Question 15

Hemophilia

Answer 15

-x-linked recessive genetic disorder

Question 16

Marfan Syndrome

Answer 16

-autosomal dominant
CT disease that primarily causes ocular, skeletal, and cardiovascular abnormalities
-between 65% and 75% of cases are inherited as an autosomal dominant trait: chromosome 15 affected that codes for fibrillin (component of CT)
-incidence of ~ 1 in 5000 people in US
-patho: genetic disorder has been mapped to chromosome 15: the gene that codes for fibrillin (component of CT)
-CM: skeletal effects, ↑’d height (tall, thin build), unusually long extremities, arachnodactyly
(spider-like appearance of hands and fingers), pectus excavatum (chest depression), pectus carinatum (chest protrusion), chest asymmetry, scoliosis and kyphosis, joint hypermobility
-ocular effects: lens displacement, elongated ocular globe causes nearsightedness, retinal detachments, most patients have correctable vision
-cardiac effects: valvular and aortic anatomic abnormalities, mitral valve prolapse, mitral valve regurgitation, aortic regurgitation (into left ventricle)
-dx: no lab tests exists to test for Marfan syndrome, need to look at medical history and all systems cited above
-tx: no established Rx exists

Question 17

Phenylketonuria

Answer 17

-inborn error of metabolism of amino acid phenylalanine
-transmitted through an autosomal recessive gene
-results in cerebral damage and mental retardation: irreversible damage is complete by age 2 or 3
-patho: patients have almost no activity of phenylalanine hydroxylase (an enzyme that converts phenylalanine to tyrosine)-results in high serum levels of phenylalanine and ↑’d urine concentrations of phenylalanine and its by-products in addition to low
tyrosine levels; levels begin to within a few days; when levels reach 30 mg/dl, cerebral damage has begun
-by age 4 months, the child shows signs of arrested brain development
-later, personality disturbances occur
-1/3 of patients have seizures usually between ages 6 and 12 months
-may have skin lesions, rough skin, show hyperactivity and irritability as well as have an awkward gait
-may notice a musty odor from the skin and urine excretion
-dx: guthrie screening test on a capillary blood sample, DNA based tests prenatally
-tx: blood levels need to be kept a 3-15 mg/dl using dietary restrictions

Question 18

Sickle Cell Anemia

Answer 18

-autosomal recessive gene mutation

Question 19

Tay-Sachs Disease

Answer 19

• congenital enzyme deficiency transmitted through autosomal recessive gene
• results in progressive mental and motor deterioration and is always fatal, usually before age 5
• patients are Ashkenazi Jewish ancestry ~ 100x more often than general public
• patho: enzyme hexosaminidase A is deficient, which is necessary for metabolism of gangliosides (glycolipids found in the CNS): without enzyme, lipid pigments accumulate and demyelinate CNS cells
• CM: child looks normal at birth, abnormal signs appear @ ~ 5 and 6 months
• progressive weakness of the neck, arm, and leg muscles prevents child from sitting up and lifting his/her head
• has difficulty turning over, can’t grasp objects, and has vision loss progressing to blindness
• by age 18 months, seizures, generalized paralysis, and spasticity
• contracts recurrent bronchopneumonia, which is usually fatal before age 5
• may see large head circumference, optic nerve atrophy, and a distinctive red cherry spot on the retina
• dx: serum analysis
• tx: no cure, so Rx is supportive (tube feedings, postural drainage)

Question 20

Scoliosis

Answer 20

• abnormal lateral curvature of the spine
• rotation of the vertebral column around its axis occurs and causes the associated rib cage deformity
• often associated with kyphosis and lordosis
• classified as idiopathic (most common), osteopathic, myopathic, or associated with various neurologic disorders
• between 0.4% and 5.5% children may present with some type of scoliosis with 1 in 4 of those requiring some type of treatment intervention
• functional or structural (genetics are believed to play a role)
• functional (postural) scoliosis may be caused by factors other than structural (pain, poor posture, leg length discrepancy, muscle spasm or spondylolisthesis)
• curves disappear when the cause is remedied
• structural scoliosis is a fixed curvature of the spine associated with vertebral rotation and asymmetry of the ligamentous supporting structures
• patho is unknown
• CM: curvatures of less than 20° (mild scoliosis) rarely cause significant problems
• severe untreated scoliosis (curvatures greater than 60°) may produce pulmonary insufficiency and ↓’d lung capacity, back pain, degenerative spinal arthritis, disk disease, vertebral subluxation, or sciatica
• characteristics of scoliosis are asymmetric shoulder and pelvic positions
• curves are designated as right or left depending on the convexity (R thoracic scoliosis describes a curve in the thoracic spine with convexity to the R)
• usually 1 primary curvature exists with a secondary or compensatory curvature that develops to balance the body
• rotational deformity (convex side) is observed as a rib hump (gibbous) sometimes seen in upright position, but apparent in the forward bend position

Question 21

Scoliosis Medical Management

Answer 21

• by clinical examination; requires the client to bend forward 90° with the hands joined in the midline as if taking a dive into a pool
• structural curvatures maintain their position irrespective of whether the spine is in an upright or forward bending position
• functional curvatures straighten when placed in a forward bend position
• full-length radiographs of the spine using techniques to minimize breast radiation dosage are evaluated using the Cobb method to measure the degree of curvature: curve must be larger than 10° to be considered scoliotic
• tx: prevention of postural or idiopathic structural scoliosis is the key to management of the majority of scoliosis cases
• early detection allows for early Rx without surgical intervention
• observation and monitoring every 4-6 months for curvatures less than 25°, spinal orthoses for curvatures 25-45°, and surgery for curvatures greater than 45° have been recommended
• surgical intervention (e.g., fusion with posterior segmental spinal instrumentation) may be necessary for curvatures greater than 45°, in chronic pain, or when curvature causes neurologic changes
• prognosis: postural curvatures resolve as the primary problem is treated, structural curvatures are not eliminated, but rather ↑ during periods of rapid skeletal growth

Question 22

SIFTT for Scoliosis

Answer 22

• screen for scoliosis and educate the public about scoliosis
• exercise programs continued to be used, but have not been found to halt or improve scoliosis even when used in conjunction with orthoses
• targeting the paraspinal muscles with exercise may not change the degree of curvature, but can help control back pain

Question 23

Neural Tube Defects

Answer 23

-congenital neural tube defects (NTDs) encompass a variety of abnormalities
-spina bifida occulta (incomplete fusion of the posterior vertebral arch)
-meningocele (external protrusion of the meninges)
-myelomeningocele (protrusion of meninges & spinal cord)
-generally these defects occur in the lumbosacral area, but also may be found in the sacral, thoracic, and cervical areas
-varies by ethnic, geographic, and socioeconomic status
-incidence appears to be declining
-etiology is multifactorial and interaction of a genetic predisposition, teratogenic exposure, and essential folic acid deficiency or folic acid metabolic disorder
-multivitamins containing folic acid taken when planning a pregnancy and during the first 6 weeks of pregnancy prevent 50-70% of NTDs
-75% of vertebral defects are located in the lumbosacral region, most commonly at the L5-S1 level
-spina bifida occulta does not protrude visibly, but is often accompanied by a depression or dimple in the skin, a tuft of dark hair, soft fatty deposits (subcutaneous lipomas or dermoid cyst), port wine nevi, or a combo of these abnormalities on the skin at the level of the underlying lesion-usually does not cause neurologic dysfunction
-spina bifida aperta (meningocele and myelomeningocele), sac-like cyst protrudes outside the spine
-meningocele rarely causes neurologic deficits (may get B&B problems or foot weakness)
-myelomeningocele causes permanent neurologic impairment depending on the level of involvement: flaccid or spastic paralysis, various combos of bowel and bladder incontinence, musculoskeletal deformities,
hydrocephalus, and sometimes mental retardation
-90% children born with this condition have an associated hydrocephalus
-often the cerebellar tonsils are displaced through the foramen magnum, resulting in obstruction of CSF flow associated with ↑’d CSF pressure and hydrocephalus: type I or Type II Arnold-Chiari malformation

Question 24

Arnold-Chiari Malformation

Answer 24

• enlarged ventricles predisposes a child with myelomeningocele to hydrocephalus
• brainstem, 4th ventricle and cerebellar tonsils displaced downward then foramen magnum which inhibits CSF flow pressure on brainstem cranial nerves causing cranial nerve palsies

Question 25

Medical Management for Neural Tube Defects

Answer 25

-detected prenatally with US scanning and serum α-fetoprotein (AFP) testing (usually occurs by 14 weeks gestation with NDTs)
-tx: cesarean section is the preferred method of birth to avoid trauma to the neural sac that occurs during vaginal delivery
-prenatal closure is now available by fetal surgery
-prospective parents should be cautioned not to expect improvement in leg function as a result of this surgery
-ventriculoperitoneal shunting is recommended in the presence of hydrocephalus; shunt revision is often required as the child grows or if the shunt becomes obstructed, infected, or separated
-results in orthopaedic issues
-medical management of the bowel and bladder dysfunction is of critical importance both from a medical and social standpoint: muscles of the bladder can show either spasticity or flaccidity leading to either a condition where the bladder is small and under high pressure from urine or large and stretched out and
under low pressure; stool incontinence is managed most commonly by a program to regulate bowel movements using diet, timed enemas, or suppositories
-prognosis: a. 85% survive into adulthood (most deaths occur before age 4)
-2/3 of children with myelomeningocele and shunted hydrocephalus have intelligence that falls in the normal range
-remaining 1/3 fall into the range for mental retardation, usually mild
-prognosis for motor function: vary according to the level of the lesion, if functional ambulation is not present by 7-9 years of age, it is unlikely to occur

Question 26

Developmental Dysplasia of Hip

Answer 26

-previously known as congenital hip dysplasia or dislocation
-common hip disorder affecting infants and children
-change in name reflects the fact that DDH is a developmental process occurring either in utero or during the first year of life
-can be unilateral or bilateral and occurs in 3 forms of varying severity: unstable hip dysplasia, in which the hip is positioned normally, but can be dislocated by manipulation; subluxation or incomplete dislocation, in which the femoral head of the femur remains in contact with the acetabulum but the head of the femur is partially displaced or uncovered; complete dislocation, in which the femoral head is totally outside the
acetabulum
-8.6-11.5/1000 live births (85% of affected infants are females)
-infant positioning, both prenatally and postnatally, may affect the formation of the acetabular cup and hip stability because the acetabulum is formed as a result of contact with the femoral head
-cultural customs
-can affect the acetabulum, femoral head, and the relationship of the femoral head to the acetabulum
-up to 12 months of age, one or more positive signs may be present
-may cause Trendelenburg gait pattern

Question 27

Hip Tests for Developmental Dysplasia

Answer 27

• Barlow maneuver: adduct with pressure dislocates hip
• Ortolani maneuver: gentle hip flexion, abduction and slight traction reduce hip with click or clunk and increased hip abduction possible and only works first few weeks
• Galeazzi test (Allis sign): supine, hips and knees flexed, feet flat, knee lower in dislocated side-assess unilateral hip dislocation (3 mo and up)
• trendelenburg sign: weight on one leg, opposite pelvis slightly elevated is negative; weight on 1 leg pelvis drops opposite side is a positive sign

Question 28

Medical Management for Developmental Dysplasias of Hip

Answer 28

• clinical examination is the most important diagnostic tool
• positive Ortolani’s or Barlow’s click confirms DDH in the first month of life
• radiographic examination is unreliable in the infant and is used more commonly in older infants and children
• tx: replacing the head of the femur into the acetabulum with no intervening soft tissue
• the proper position then must be maintained for a period of time
• infant placement of the hip in a position of 100° flexion and 90° abduction until the joint capsule tightens and the acetabulum is molded to assume a cup shape
• can be accomplished through the use of a hip harness such as the Pavlik harness
• prognosis: if dislocation is corrected, success is as high as 95% for normal hip development
• satisfactory outcome of 86% with surgical reduction

Question 29

SIFTT for Developmental Dysplasias of Hip

Answer 29

• often PTs may be first healthcare worker to observe signs of hip pathology
• an awareness of quick screening strategies for hip dysplasia is critical

Question 30

Muscular Dystrophies

Answer 30

• largest and most common group of inherited progressive neuromuscular disorders of childhood affecting all population types even animals
• genetic origin and is characterized by ongoing symmetric muscle wasting without neural or sensory deficits, but with ↑’ing deformity and disability
• in some forms, wasted muscles tend to hypertrophy because of connective tissue and fat deposits, giving the visual appearance of muscle strength
• Duchenne’s Muscular Dystrophy (DMD) is ~ 1 in 3,500 live births
• patho: knowledge of muscular dystrophies and understanding of their ↑’ing complexities escalated dramatically in the late 1980s when the protein dystrophin was identified as the causative factor in many types of MD

Question 31

Duchenne and Becker’s Muscular Dystrophy

Answer 31

• DMD and BMD – X-linked recessive (female carrier, happens in males)
• DMD much more severe than BMD
• affected gene in DMD/BMD encodes messenger RNA (mRNA) for the dystrophin that is located in the muscle membrane, the sarcolemma: dystrophin is the protein that links the sarcolemma with the contractile muscle protein (actin)
• lack of normal dystrophin makes the sarcolemma susceptible to damage during contraction and relaxation cycles
• disruption of the muscle membrane and muscle fiber necrosis are initiated by muscle contraction, especially eccentric contraction
• absence (DMD) or low levels of dystrophin (BMD) can destabilize the membrane
• muscle cells are replaced by fatty tissue and CTs and contractures develop
• fat cells continue to accumulate between damaged muscle fibers
• CM: people with MD have muscular weakness, wasting and hypotonia, degree of severity and age of onset vary with the type of MD present
• DMD
• Gower’s sign: places hand on thighs and walks up legs with hands until weight of trunk can be placed posterior to hip joint leads to characteristic weakness of lumbar and gluteal muscles
• prognosis: varies with the type of MD present, pulmonary complications resulting from respiratory muscle dysfunction or cardiomyopathy are common sources of morbidity and mortality

Question 32

SIFTT for Muscular Dystrophy

Answer 32

• precautions
• when people with MD become ill or injured and are on bed rest, even for a few days, they may lose many of their functional abilities
• for example, a child who falls and breaks a leg and is on bed rest or immobilized may never regain the ability to ambulate
• children should be encouraged to be as mobile as possible
• strenuous exercise may facilitate the breakdown of muscle fibers
• low-repetition maximum weightlifting, especially eccentric strengthening, is not recommended
• exercise is best done in the pool where exercise is concentric
• post exercise should produce only minimal fatigue with no soreness

Question 33

Torticollis

Answer 33

• congenital muscular torticollis (CMT)
• twisted neck and is a contracted state of SCM muscle producing head tilt to affected side with rotation of chin to opposite side
• variety of possible causes of congenital muscular torticollis exist, but etiology remains unknown
• patho: venous occlusion in addition to arterial occlusion possible explanation for some
• tx: initial management involves a period of active observation for spontaneous resolution: therapy to correct positional/deformational effects is mainstay of Rx for CMT
• interventions include twice daily PROM to stretch shortened muscle preceded by warm compresses, massage, and slight traction to relax the muscle before stretching; stabilization of proximal attachment of SCM and trapezius is important during ROM
• positioning is important to encourage erect and midline head posture
• prognosis: CMT usually resolves with conservative tx, left untreated or poorly managed, chronic, unresolved torticollis can result in persistent deformity and asymmetry of head shape and position

Question 34

Osteogenesis Imperfecta

Answer 34

• brittle bones, rare congenital disorder of collagen synthesis affecting the bones and CT
• mutations affecting genes which code for type I collagen
• type I collagen is in bone, skin, and tendon: major structural protein of these tissues
• wide range of clinical presentations ranging from a normal appearance with occasional fractures to severe involvement with growth retardation and long bone and spinal deformities: shortened stature is common
• these children often bruise easily, and ligaments tend to show ↑’d laxity
• additional clinical features may include blue or tinted (purple, gray) sclerae, thin skin, joint hypermobility, deformity of bony auditory structures with subsequent hearing impairment, scoliosis, pectus deformity, deformed teeth, a tendency toward recurrent epistaxis, excess diaphoresis, cardiovascular complications (e.g. aortic and mitral valve insufficiency, aortic dissection), and metabolic defects (e.g. ↓’d platelet aggregation)

Question 35

SIFTT for Osteogenesis Imperfecta

Answer 35

• precautions: infants and children require careful handling to prevent fractures; rotational forces are contraindicated, but gently stretching in straight planes and myofascial stretching are acceptable
• family education: educational material and info can be obtained from the Osteogenesis Imperfecta Foundation
• family must be instructed in handling and positioning techniques
• precautions should be given to avoid lifting the child under the arms or by the hands
• young child should not be tossed into the air or be involved in roughhouse play
• at the same time, families should be encouraged to hold and play with their child appropriately and to help the child develop interests that do not require strenuous physical activity
• swimming frequently is recommended, but the child must be monitored carefully to avoid falls in the shower and pool area