Diploid-triploid mosaicism

Diploid-triploid mosaicism is a rare chromosomal disorder characterized by the presence of two distinct cell lines within an individual: one with a diploid set of chromosomes (46 chromosomes) and one with a triploid set of chromosomes (69 chromosomes). This condition is a type of chromosomal mosaicism, where different cells in the body have different genetic makeups.

Genetics

In diploid-triploid mosaicism, the diploid cells contain the normal two sets of chromosomes, while the triploid cells contain three sets of chromosomes. This results from an error in cell division during the early stages of embryonic development. The presence of triploid cells can affect various tissues and organs, leading to a wide range of clinical manifestations.

Clinical Features

The clinical presentation of diploid-triploid mosaicism can vary widely depending on the proportion and distribution of diploid and triploid cells in the body. Common features may include:

• Growth retardation
• Developmental delays
• Intellectual disability
• Distinctive facial features
• Congenital anomalies, such as heart defects and limb abnormalities

Diagnosis

Diagnosis of diploid-triploid mosaicism typically involves cytogenetic analysis, such as karyotyping or fluorescence in situ hybridization (FISH), to identify the presence of both diploid and triploid cell lines. Prenatal diagnosis may be possible through amniocentesis or chorionic villus sampling.

Management

There is no cure for diploid-triploid mosaicism, and management focuses on addressing the specific symptoms and complications associated with the condition. This may involve a multidisciplinary approach, including:

• Regular monitoring of growth and development
• Early intervention programs for developmental delays
• Surgical correction of congenital anomalies
• Supportive therapies, such as physical, occupational, and speech therapy

Prognosis

The prognosis for individuals with diploid-triploid mosaicism varies widely and depends on the severity of the associated anomalies and the proportion of triploid cells. Some individuals may have relatively mild symptoms, while others may experience significant health challenges.

Related Pages

• Chromosomal mosaicism
• Karyotyping
• Fluorescence in situ hybridization
• Amniocentesis
• Chorionic villus sampling