chromosome 15q24 deletion syndrome

Chromosome 15q24 deletion syndrome is a multisystem condition caused by a small missing segment of chromosome 15 that removes several genes, including SIN3A. The deletion disrupts typical growth and development, leading to a combination of physical differences and neurodevelopmental challenges that usually become apparent in infancy or early childhood. Because the syndrome affects fewer than one in a million people worldwide, many families and clinicians may be unfamiliar with its full spectrum. Most reported cases occur sporadically, but the change can occasionally be passed from an affected parent in an autosomal dominant manner. Ongoing research is expanding understanding of how best to support individuals with this condition across the lifespan.

The clinical picture is broad and varies considerably between individuals. Early clues often include pre- and post-natal growth delay, distinct facial features such as a long face, wide nasal bridge, long philtrum, hypertelorism, and downslanted palpebral fissures, as well as congenital anomalies like diaphragmatic hernia or undescended testes in boys. Cognitive and developmental features are prominent: most children have intellectual disability that can range from mild to severe, delayed speech and language, motor incoordination, and joint hypermobility. Behavioral challenges such as hyperactivity, autism spectrum characteristics, and episodes of aggressive behavior are frequently reported. Over time, additional issues may emerge, including strabismus affecting vision, hearing impairment, feeding difficulties that can contribute to obesity, or clinodactyly of the fifth finger. Although these findings are commonly described, not all individuals experience every feature, and the severity and combination of symptoms differ widely. Regular developmental assessments help track progress and guide supportive therapies tailored to each child’s needs.

Chromosome 15q24 deletion syndrome results from a missing segment of DNA on the long arm (q arm) of chromosome 15. The deleted region spans 1.7 to 6.1 megabases and removes several genes; loss of SIN3A is thought to play a key role in the neurological and developmental aspects of the disorder. Most deletions arise de novo, meaning they occur for the first time in the affected individual and are not present in either parent. When a parent does carry the same deletion, it follows an autosomal dominant inheritance pattern, so each child of that parent has a 50% chance of inheriting the deletion. Even among relatives who share the deletion, the specific symptoms and their severity can vary considerably, a concept known as variable expressivity. Families are encouraged to meet with a genetic counselor to discuss testing options for relatives and to understand reproductive risks, which are generally low after a de novo event but depend on whether a parent carries the deletion.

Currently, management focuses on supportive care and symptom management. Care is typically coordinated by a multidisciplinary team that may include geneticists, developmental pediatricians, surgeons, ophthalmologists, audiologists, and therapists. Early intervention with speech, occupational, and physical therapies supports developmental progress, while behavioral therapy can address hyperactivity or autism-related challenges. Surgical repair may be necessary for diaphragmatic hernia or undescended testes, and regular ophthalmologic and audiologic evaluations help identify correctable vision or hearing problems. Because the condition can affect multiple organ systems, regular surveillance is an essential part of long-term care, helping to identify potential complications before they become serious. Genetic counseling provides families with information about inheritance, testing of relatives, and family-planning options.

Outcomes for individuals with chromosome 15q24 deletion syndrome depend on the combination and severity of their features as well as the timing of interventions. Many children make developmental gains with tailored therapies, though intellectual disability and learning challenges typically persist into adulthood. Medical issues such as congenital diaphragmatic hernia or significant feeding difficulties can influence overall health, but proactive monitoring and modern surgical care have improved survival and quality of life. Severity and symptoms vary widely between individuals, so long-term outlook must be considered on a case-by-case basis. Outcomes described in medical literature continue to evolve as standards of care improve. Families often find it helpful to connect with genetic counselors and multidisciplinary specialists experienced with this syndrome to plan comprehensive care and access community resources.

Clinical trials are underway exploring new treatment approaches and the underlying biology of the 15q24 region. Individuals interested in clinical trials can search ClinicalTrials.gov or consult their care team about eligibility.