chromosome 1q21.1 deletion syndrome

Chromosome 1q21.1 deletion syndrome is a recurrent chromosomal deletion syndrome that presents with a broad range of clinical manifestations, particularly affecting neurodevelopment. It is characterized by subtle facial features, growth variations, and developmental differences, with many individuals experiencing challenges with intellectual function and global developmental delays. Most cases occur sporadically in an autosomal dominant pattern, and the exact prevalence remains unknown. , the syndrome lacks the clinical features associated with thrombocytopenia-absent radius syndrome.

Individuals with chromosome 1q21.1 deletion syndrome show a variable clinical picture. Neurologically, many affected children experience intellectual disability and global developmental delay, and some may exhibit autism spectrum features. Characteristic physical features include microcephaly, short stature, and several craniofacial differences such as epicanthus, a high palate, deeply set eyes, a bulbous nose, a long philtrum, frontal bossing, and a wide nasal bridge. Additional findings, which can be seen in a subset of individuals, include hypotonia, joint hypermobility, motor stereotypy, clinodactyly of the fifth finger, scoliosis, and other anatomical variations. Not all individuals experience all features, and severity varies considerably.

The genetic basis of chromosome 1q21.1 deletion syndrome is thought to result from a recurrent deletion in the 1q21.1 region. Although specific gene contributions have not been isolated, this chromosomal deletion leads to a disruption of multiple genes, and the precise mechanisms remain under investigation. The condition is largely sporadic but follows an autosomal dominant inheritance pattern, meaning that while most cases are de novo, an affected individual can pass the deletion on to their offspring. Genetic counseling is recommended to help families understand the implications of this inheritance pattern.

Currently, management focuses on supportive care and symptom management, as no specific treatments have been approved for chromosome 1q21.1 deletion syndrome. Treatment is highly individualized and typically involves a multidisciplinary team that may include developmental pediatricians, neurologists, and other specialists to address cognitive, behavioral, and physical challenges. Regular surveillance is an essential part of long-term care, helping to identify complications early and tailor interventions to the patient's evolving needs. Families are encouraged to discuss treatment options and supportive therapies with their healthcare team, and genetic counseling is recommended for ongoing guidance.

Outcomes for individuals with chromosome 1q21.1 deletion syndrome can vary widely, with the overall course depending on the severity of symptoms and the availability of specialized care. Many individuals continue to develop and adapt over time, and although some may face ongoing challenges with cognitive and physical development, current standards of care have improved quality of life. Outcomes described in medical literature continue to evolve as standards of care improve. Families often find it helpful to connect with specialists familiar with this condition, and genetic counseling can provide valuable guidance regarding long-term management and family planning.

A clinical trial is underway exploring new treatment approaches for chromosome 1q21.1 deletion syndrome. Individuals interested in clinical trials can search ClinicalTrials.gov or consult their healthcare team about eligibility and current research opportunities.