Trisomy 22

A chromosomal disorder involving an extra chromosome 22

Trisomy 22 is a chromosomal disorder in which there are three copies of chromosome 22 instead of the usual two. This condition can lead to a variety of developmental and physical abnormalities.

Presentation

Trisomy 22 can manifest in several forms, including full trisomy 22, mosaic trisomy 22, and partial trisomy 22. Each form has distinct characteristics and outcomes.

Full Trisomy 22

Full trisomy 22 is typically not compatible with life, and most affected pregnancies result in miscarriage. It is one of the more common chromosomal abnormalities found in miscarriages.

Mosaic Trisomy 22

In mosaic trisomy 22, some cells have the extra chromosome while others do not. This can result in a wide range of symptoms, from mild to severe, depending on the proportion of affected cells.

Partial Trisomy 22

Partial trisomy 22 occurs when only a segment of chromosome 22 is present in triplicate. The symptoms and severity depend on the specific segment that is duplicated.

Symptoms

Individuals with trisomy 22 may exhibit a variety of symptoms, including:

• Developmental delays
• Intellectual disability
• Congenital heart defects
• Distinctive facial features
• Growth retardation

Diagnosis

Trisomy 22 is typically diagnosed through prenatal testing methods such as amniocentesis or chorionic villus sampling, which can detect chromosomal abnormalities. Postnatal diagnosis may involve a karyotype analysis to confirm the presence of an extra chromosome 22.

Prognosis

The prognosis for individuals with trisomy 22 varies widely depending on the type and severity of the condition. Full trisomy 22 is usually fatal, while individuals with mosaic or partial trisomy 22 may survive with varying degrees of disability.

Management

Management of trisomy 22 is supportive and symptomatic, focusing on addressing the specific health issues and developmental needs of the individual. This may involve a team of specialists, including pediatricians, cardiologists, and developmental therapists.

Related pages

• Chromosomal disorder
• Karyotype
• Prenatal diagnosis

References

Chromosome 22