Guidelines
Guidelines Summary
Guidelines for the management of children with achondroplasia are available from the American Academy of Pediatrics. [10] The guidelines deal with examination and anticipatory guidance for patients from birth to early adulthood. They include the following for patients from birth to age 1 month:
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Confirm the diagnosis by radiographic studies
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Document measurements, including occipital-frontal circumference (OFC), body length, and body weight; plot these measurements on achondroplasia-specific growth charts; review the phenotype with the parents and discuss the specific findings with both parents whenever possible
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Measure the OFC at every pediatric contact during the first year
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Discuss the specific findings of achondroplasia with the parents (eg, that most individuals with achondroplasia have normal intelligence and life expectancy, that only 5-10% of infants with achondroplasia experience serious problems during infancy, and that growth hormones or other drug therapies or food or vitamin supplements do not significantly increase stature)
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If severe problems are found (eg, profound hypotonia or sustained ankle clonus, markedly diminished foramen magnum size compared with the achondroplasia standard, substantial deformation of the upper cervical spinal cord, hypoxemic episodes with minimal oxygen saturations below 85%), referral to a neurosurgeon or other physician skilled and experienced in the care and treatment of neurologic problems in children with achondroplasia should be initiated
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If the OFC is large or crosses percentiles on the achondroplasia-specific head-circumference chart, it is appropriate to refer the infant to a pediatric neurologist or pediatric neurosurgeon (although hydrocephalus is a lifelong risk, it is most likely to occur during the first 2 years)
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If there are signs of respiratory distress or evidence of poor weight gain despite adequate caloric intake, pulse oximetry (during feeding, when crying, and at rest) should be considered to monitor oxygenation
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Because most infants with achondroplasia develop a thoracolumbar kyphosis, parents should be counseled to avoid unsupported sitting and to avoid devices that cause curved sitting or “C sitting,” such as “umbrella-style” strollers and soft canvas seats during the first year of life; use of feeder seats for upright positioning should be recommended
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If severe kyphosis appears to be developing, consider a pediatric orthopedic surgical assessment to determine if bracing is needed
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Because severe thoracolumbar kyphosis is one mechanism that can give rise to spinal stenosis, unsupported sitting before there is adequate trunk muscle strength is discouraged
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Discuss the potential psychosocial implications that the child's disproportional short stature has for both the child and his or her parents
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Physicians should also refer the child or parents to a support group or other sources of support, provide educational books and pamphlets to the parents, discuss functional problems faced by individuals with achondroplasia, and review the prenatal diagnosis and recurrence risks for subsequent pregnancies
Japanese guidelines regarding the clinical management of achondroplasia, by Kubota et al, include the following recommendations [36] :
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It is recommended that cranial magnetic resonance imaging (MRI) be used to identify spinal cord compression resulting from foramen magnum stenosis
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It is recommended that foramen magnum decompression be carried out in cases of spinal cord compression resulting from foramen magnum stenosis associated with neurologic symptoms, abnormal neurological findings, and central respiratory disorders
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It is recommended that ventricular enlargement with neurologic symptoms (hydrocephalus) be identified via cranial MRI
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It is recommended that ventricular enlargement associated with neurologic symptoms (hydrocephalus) be managed with shunt surgery
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Management of obstructive sleep apnea through noninvasive positive pressure ventilation is suggested
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It is suggested that when obstructive sleep apnea exists in the presence of tonsillar/adenoid hypertrophy, surgical treatment be carried out
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It is recommended that spinal canal stenosis associated with neurologic symptoms be managed through surgical decompression
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It is suggested that after age 12 years and with informed assent, leg lengthening should be possible
Media Gallery
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Infant with rhizomelic form of chondrodysplasia punctata (left). Note rhizomelic shortening of limbs, disproportionately short stature, enlarged joints, and contractures. Radiographs depict epiphyseal stipplings on the proximal humerus, both ends of the femora, and lower spine.
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Brother and sister with mesomelic dysplasia (homozygous dyschondrosteosis gene) and a woman with Leri-Weill syndrome. Note disproportionately short stature with mesomelic shortening and deformities of forearms and legs (in mesomelic dysplasia) and short forearms with Madelung-type deformity (in Leri-Weill syndrome).
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Infant with Beemer-type (left) and an infant with Majewski-type (right) short-rib syndrome (SRS). Note severe micrognathia/retrognathia with cleft palate, apparently low-set and malformed ears, small and narrow chest, protuberant abdomen with omphalocele, and short and slightly curved limbs with bilateral postaxial polydactyly (Beemer-type SRS), a large head, short nose, flat nasal bridge, central cleft of upper and lower lips, short neck, short chest, protuberant abdomen, abdomen, ambiguous genitalia, short limbs, and preaxial and postaxial polydactyly (Majewski-type SRS).
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Infant and 2 children with achondroplasia. Note relatively normal-sized trunk, a large head, rhizomelic shortening of the limbs, lumbar lordosis, and trident hands. Radiographs demonstrate abnormal pelvis with small square iliac wings, horizontal acetabular roofs, and narrowing of the greater sciatic notch, an oval translucent area at the proximal ends of the femora, caudal narrowing of the interpedicular distances in the lumbar region, short pedicles, and lumbar lordosis.
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Infant with thanatophoric dysplasia. Note short-limbed dysplasia, large head, short neck, narrow thorax, short and small fingers, and bowed extremities. Radiographs demonstrate thin flattened vertebrae, short ribs, small sacrosciatic notch, extremely short long tubular bones, and markedly short and curved femora (telephone receiver–like appearance).
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Infant with atelosteogenesis. Note short-limbed dysplasia, relative macrocephaly, and short neck. Radiographs demonstrate boomeranglike triangular or oval form of the long bones (humeri), absent radii, markedly delayed ossification of phalanges, short femora, and absent fibulae.
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Child with Hurler syndrome (mucopolysaccharidosis type IH). Note dysplasia, scaphocephalic macrocephaly, coarse facial features, depressed nasal bridge, broad nasal tip, thick lips, short neck, protuberant abdomen, inguinal hernia, joint contractures, and claw hands. Radiographs demonstrate hook-shaped deformity (anterior wedging) of the L1 and L2 vertebrae; abnormally short, wide, and deformed tubular bones (bullet-shaped) of the hands; and narrow base of the second-to-fifth metacarpals. The distal articular surfaces of the ulna and radius are slanted toward each other.
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Two infants with perinatal lethal form of osteogenesis imperfecta. Note short-limbed skeletal dysplasia, deformed extremities, and relatively large head. Radiographs show short, thick, ribbonlike long bones with multiple fractures and callus formation at all sites (ribs, long bones).
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Infant with Larsen syndrome. Note the flat face with depressed nasal bridge, prominent forehead, hypertelorism, cleft palate, talipes equinovarus, and dislocations of elbows, hips, and knees. Radiograph demonstrates dislocation at the knee.
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Child with Robinow syndrome. Note moderate short stature, flat facial profile (fetal face–like appearance), short forearms, and small hands.
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