camptodactyly-tall stature-scoliosis-hearing loss syndrome

Camptodactyly-tall stature-scoliosis-hearing loss syndrome (CATSHL) is a very rare hereditary condition that primarily affects the skeleton, joints, spine, hearing, and, in some individuals, development. It results from a missense change in the FGFR3 gene, whose protein normally acts as a brake on bone growth; the altered protein works less well, allowing excessive or uneven growth. Features usually become apparent in childhood when tall stature, finger contractures, spinal curvature, or hearing problems draw medical attention. Fewer than one in a million people are believed to be affected, and published reports describe about 30 individuals from a single extended family.

The condition has several hallmark skeletal findings. Virtually all affected individuals are unusually tall for their age and have long, slender fingers (arachnodactyly). Camptodactyly, a fixed bending of one or more fingers, and progressive scoliosis are common and often prompt orthopedic evaluation. A high-arched palate can contribute to dental or feeding challenges. Hearing issues are another defining feature. Most people with CATSHL experience bilateral sensorineural hearing impairment that may be present from childhood and can range from mild to profound. Early audiologic assessment helps guide timely use of hearing aids or other supports. Many, but not all, individuals also have cognitive or developmental differences. Intellectual disability and global developmental delay have been reported in the majority of described cases, highlighting the need for early developmental services and individualized education plans. Spinal curvature can worsen during rapid growth spurts in adolescence, and finger contractures may restrict hand function over time. Despite these trends, not all individuals experience all features, and severity varies considerably from person to person.

CATSHL is caused by pathogenic variants in the FGFR3 gene. FGFR3 encodes fibroblast growth factor receptor 3, a protein that normally limits bone growth. The missense variant reported in affected family members reduces FGFR3 activity, leading to accelerated or uneven skeletal growth and the other characteristic features. Multiple inheritance patterns have been reported. In the family described in the medical literature, the condition follows an autosomal dominant pattern, meaning one altered copy of FGFR3 is sufficient to cause symptoms and each child of an affected individual has a 50 percent chance of inheriting the variant. Autosomal recessive inheritance has also been proposed; in that scenario, parents who each carry one altered copy of FGFR3 have a 25 percent chance with each pregnancy of having an affected child. Even within the same family, the specific features and their severity can differ greatly, a phenomenon known as variable expressivity. Genetic counseling is recommended for families to clarify individual recurrence risks and discuss testing options for relatives.

Currently, management focuses on supportive care tailored to each person’s needs. Orthopedic specialists monitor spinal curvature and finger contractures, recommending physical therapy, bracing, or surgery when necessary. Audiologists and otolaryngologists address hearing impairment with hearing aids or, in selected cases, cochlear implantation. Early intervention programs, speech therapy, and special education services support cognitive and developmental challenges. Because the condition affects multiple body systems, care is best coordinated by a multidisciplinary team familiar with skeletal disorders, hearing loss, and developmental medicine. Regular surveillance is an essential part of long-term care, helping to identify progression of scoliosis, changes in joint mobility, or emerging hearing issues before they become difficult to manage. Families are encouraged to discuss individualized monitoring schedules with their specialists and to seek genetic counseling when planning future pregnancies.

Available information suggests that CATSHL is compatible with a normal lifespan, although orthopedic complications and hearing impairment can affect quality of life. Severity and symptoms vary widely between individuals. Early detection of scoliosis, timely hearing support, and access to developmental services can improve daily functioning and educational outcomes. Outcomes described in medical literature continue to evolve as standards of care improve. Families often find it helpful to connect with specialists experienced in skeletal dysplasias and to participate in registries that track long-term health and support research.