hipocondroplasia

Hypochondroplasia, also spelled hipocondroplasia, is a rare genetic skeletal dysplasia characterized by short stature and relatively mild limb shortening compared with more severe forms such as achondroplasia. It is typically caused by activating mutations in the FGFR3 gene and is usually inherited in an autosomal dominant pattern, though many cases arise from new mutations.

Most individuals with hypochondroplasia present in childhood with short stature and disproportionately short limbs while the trunk remains relatively normal in length. Craniofacial features are often subtle, and intelligence is usually normal. Some people experience joint stiffness or limited range of motion, mild lumbar lordosis, and, in adolescence or adulthood, potential spinal or leg alignment issues. The severity of symptoms can vary widely even within families.

Diagnosis is based on clinical evaluation supported by radiographic findings, which may show shortened proximal long bones and mild vertebral changes. Confirmation is achieved through genetic testing for FGFR3 mutations. The differential diagnosis includes other forms of skeletal dysplasia, particularly achondroplasia and spondyloepiphyseal dysplasia.

Management is multidisciplinary and individualized, focusing on monitoring growth and development, orthopedic care, physical and occupational therapy, and addressing any spinal or joint problems. There is no cure. Growth hormone therapy has been explored in some cases but is not widely adopted as standard treatment. Life expectancy is near normal, and intelligence is typically not affected; most individuals can lead active lives with appropriate medical and supportive care.