3.8 of 26 Ratings
Survival motor neuron protein deficiency leads to:
Progressive replacement of muscle tissue with fibrous and fatty tissue, causing calf pseudohypertrophy
Loss of anterior horn cells and progressive muscle weakness
Abnormal chondroid production by chondroblasts in the proliferative zone of the physis
Disturbances in cell metabolism with accumulation of sphingolipids in the liver, spleen and bone marrow
Fetal acetylcholine receptor inhibition and nonprogressive joint contractures
Select Answer to see Preferred Response
Which of the following is INCORRECT regarding scoliosis in the setting of spinal muscular atrophy (SMA)?
Curve flexibility tends to be higher than for idiopathic curves
Most curves tend to be long, C-shaped thoracolumbar curves
The primary surgical goal for correction is to obtain fusion in a position that will maintain sitting balance and prevent decline of pulmonary function
Curve magnitude correlates strongly with ambulatory status
Anterior release/fusion with posterior fusion are typically required for adequate surgical correction
A newborn infant is born with the physical exam finding shown in the video below. In addition, the child has absent deep tendon reflexes and hypotonia. Which of the following abnormalities is most likely responsible for these findings?
Gene mutation in SMN1
Deficiency of Dystrophin protein
Gene mutation in COMP
Gene mutation in COL1A1
A 12-month-old male presents with symmetric, progressive weakness that is more profound in lower extremity than upper extremity. On physical exam, he can sit but cannot walk. He has tongue fasciculations and absent deep tendon reflexes. Serum creatine phosphokinase and aldolase levels are normal. Which of the following genetic mutations or deletions is responsible for his condition?
Androgen receptor gene
A 3-month-old infant presents to your clinic with difficulty moving his extremities. The child had an uneventful prenatal course and birth, but since birth he has had poor head control and difficulty feeding. On physical exam, he is able to move all extremities, but he moves his upper extremities more than his lower extremities, and his hands more than his shoulders. He has no spasticity, but global weakness. The patient’s deep tendon reflexes are absent, but he has tongue fasciculations. What is the cellular pathology and prognosis for this patient?
The patient has a nonprogressive injury to his brain, and he will likely require multiple orthopaedic surgeries in the future as a result of muscle imbalance
The patient has an absent dystrophin protein and will likely require a wheelchair by the age of 15 and will die of cardiorespiratory problems by the age of 20
The child will have a progressive loss of alpha-motor neurons in anterior horn of spinal cord. He will have difficulty walking, but will be able to sit independently and will likely live into the fifth decade of life
The child will have a progressive loss of alpha-motor neurons in anterior horn of spinal cord and will unlikely live past the age of two
The child will likely go on to develop a cavus foot and hammer toes, but he should live a full healthy life
A 7-year-old girl with spinal muscular atrophy (SMA) type II has popping of the left hip. Examination reveals painless subluxation of the joint in adduction with palpable reduction in abduction. Radiographs show coxa valga, subluxation of the left hip, and pelvic obliquity with elevation of the left hemipelvis. Treatment should consist of
bilateral adductor and iliopsoas releases, with nighttime abduction bracing.
proximal femoral varus osteotomy with internal fixation.
proximal femoral varus osteotomy with volume-reducing periacetabular osteotomy.
proximal femoral varus osteotomy with shelf acetabular augmentation.
An autosomal recessive disorder caused by a homozoygous deletion in the survival motor neuron 1 (SMN1) gene would result in which of the following?
Global hypotonia, difficulty swallowing, absent deep tendon reflexes, and tongue atrophy, with disease onset within the first 6 months of birth.
Delayed motor milestones, scoliosis, and joint contracture, with disease onset around 6-18 months of age
Scoliosis, hand tremors, increased lumbar lordosis, and bilateral Trendelenburg lurch, with disease onset later in life (>18 months of age).
Any of the above
None of the above