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Spectrum of different syndromes characterized by
persistent multiple limb contractures. Often associated with midline
dysraphism abnormalities. Distal arthrogryposis type I and Freeman-Sheldon
Syndrome (FSS) are the most common forms. Often associated with
pharyngeal, cardiac, urologic, and gastric abnormalities.
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- Distal Arthrogryposis, Type I: Characterized by distal involvement of hands and feet, medially
overlapping fingers, clenched fists, camptodactyly, and clubfoot. Neurologic
development is normal and Response to physical therapy usually is good.
- Distal Arthrogryposis Type II: Heterogenous group. Congenital distal joint contractures are associated
with numerous other anomalies.
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Varies from 0.3 to 3 cases per 1000 live births. No
racial or sexual predilection has been reported (except for cases with
X-linked transmission).
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Most cases are sporadic. Type 1 may be
autosomal dominant inherited (chromosome 9), but autosomal recessive
transmission has been reported. Some syndromes in which arthrogryposis is
part of the clinical picture have X-linked transmission. Identical twins
often are discordant for the condition, and the intrafamilial phenotype is
highly variable.
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The pathogenetic mechanism is a matter of debate.
Most likely it is a combination of a central and a peripheral neuromuscular
disease. Generalized fetal akinesia seems to be a significant risk factor,
which also is favored by oligohydramnios, anomalies of the uterus, and twin
pregnancies. Several etiologic theories have been postulated: hormonal,
fetal blood supply, neurogenic or myogenic disturbances, toxins (e.g.,
alcohol or drugs such as phenytoin), and maternal infections (e.g., rubeola,
rubella, coxsackievirus, enterovirus). Arthrogryposis is classified into
four categories: myopathies, neuropathies, connective tissue disorders, and
exogenous effects.
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There are few prenatal ultrasonic findings. The clinical
diagnosis usually is made at birth, with the characteristic positioning,
internal rotation at the shoulders, extension at the elbows, and flexion at
the wrists. Severe equinovarus deformity of the feet usually is present. The
face is round (although asymmetry is common) and often associated with a
frontal midline capillary hemangioma, flat nasal bridge, and mild
micrognathia. Depending on the cause of arthrogryposis, intelligence may be
normal. Fetal akinesia may be associated with intrauterine growth
retardation, craniofacial anomalies, and hypoplastic lungs. Two thirds of
arthrogryposis patients have involvement of all four limbs (usually
symmetrically), one fourth of patients have predominant involvement of the
lower limbs, and the rest have involvement of mainly the upper limbs.
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Numerous syndromes include at least some aspects
of arthrogryposis. In general, the deformities are symmetrical, with
increasing severity distally. Hands and feet are affected the most.
Radioulnar synostosis and syndactyly may add to the deformities.
Contractures and rigidity of the joints are common and may result in joint
pterygia and dislocation of the large joints (e.g., hip, knee, shoulders,
elbow). Mobility in the temporomandibular joint often is significantly
decreased. Spinal canal stenosis, atlantoaxial instability, and/or fusion of
cervical vertebrae have been described. Scoliosis is not uncommon and may
result in abnormal lung function. Muscle atrophy, absence of muscles, and
structural abnormalities of the muscles may ...