What Is Deletion Syndrome?

Deletion syndrome refers to a genetic condition caused by the loss or deletion of a specific region of DNA from a chromosome. This loss can result in the absence or reduction of certain genes, leading to a range of physical, developmental, and intellectual disabilities.

The effects of deletion syndrome vary widely depending on the size and location of the deleted region. Some common features include:

- Developmental delays: Individuals with deletion syndrome may experience delays in reaching developmental milestones, such as sitting, walking, and speaking.

- Intellectual disabilities: Varying degrees of intellectual disability are common in deletion syndromes. The severity of the disability can range from mild to profound.

- Physical abnormalities: Physical abnormalities associated with deletion syndromes can include unusual facial features, short stature, and musculoskeletal problems.

- Medical problems: Individuals with deletion syndrome may be more susceptible to certain medical conditions, such as heart defects, seizures, and immune system problems.

Specific examples of deletion syndromes include:

- Cri du chat syndrome: Caused by a deletion on chromosome 5, cri du chat syndrome is characterized by a high-pitched cat-like cry, distinctive facial features, intellectual disability, and delayed development.

- Prader-Willi syndrome: Resulting from a deletion on chromosome 15, Prader-Willi syndrome leads to low muscle tone, excessive eating and weight gain, intellectual disability, and behavioral problems.

- Angelman syndrome: Caused by a deletion on chromosome 15, Angelman syndrome is associated with severe intellectual disability, speech impairment, seizures, and a happy demeanor.

- Williams syndrome: A deletion on chromosome 7 causes Williams syndrome, which is characterized by a distinctive facial appearance, cardiovascular problems, intellectual disability, and a friendly and sociable personality.

Deletion syndromes are diagnosed through genetic testing, which can identify the specific chromosomal region that has been deleted. Early diagnosis and intervention are important for managing the symptoms and improving the overall quality of life for individuals with deletion syndromes.