Causes
An abnormal growth of cartilage and bone leads to hypochondroplasia, a genetic disorder caused by mutations in the FGFR3 gene. A person with hypochondroplasia only needs one copy of the mutated gene from either parent in order to develop the condition, as it is inherited in an autosomal dominant pattern.
Symptoms
Hypochondroplasia typically manifests in infancy or early childhood, causing:
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Adult height typically ranges from 3 to 4 feet
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A shortening of the limbs, especially the upper arms and thighs
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Body proportions are disproportionate, with a short trunk and normal-sized head and face
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Joint hypermobility due to mild to moderate joint laxity
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Some cases of mild intellectual disability
Diagnosis
In order to diagnose hypochondroplasia, a combination of clinical evaluation, radiographic imaging, and genetic testing is necessary. Key diagnostic features include:
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A physical examination reveals characteristic signs of short stature and disproportionate limbs
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Skeletal X-rays showing specific skeletal abnormalities, such as shortened long bones and squared iliac wings
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Testing for hypochondroplasia-related mutations in the FGFR3 gene
Treatment
Hypochondroplasia is treated by managing symptoms and improving quality of life. Treatment options include:
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Children with hypochondroplasia can benefit from growth hormone therapy to promote linear growth
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Strengthening and improving mobility through physical therapy
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A limb-lengthening surgery can be performed in severe cases of limb disproportion to correct it
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Support and counseling for individuals and families coping with genetic disorders
Prevention
Since hypochondroplasia is a genetic disorder, there are no specific preventive measures to prevent its occurrence. However, individuals who have a family history of hypochondroplasia or other FGFR3-related conditions may benefit from genetic counseling. The benefits of genetic counseling include information on inheritance risks and family planning options.
Conclusion
An autosomal dominant inheritance pattern causes homochondroplasia, a genetic disorder characterized by short stature, disproportions in the limbs, and abnormalities. Diagnosis Involves Clinical Evaluation, Radiographic Imaging, and Genetic Testing. Treatment Aims to Manage Symptoms and Improve Quality of Life, With Options Including Growth Hormone Therapy and Physical Therapy. Individuals with a family history of hypochondroplasia may benefit from genetic counseling to understand their risk and make informed decisions about family planning.
