What are the symptoms of Pallister-Killian mosaic syndrome?

Individuals with Pallister-Killian mosaic syndrome typically have low muscle tone at birth (hypotonia), sparse scalp hair, a high forehead, a coarse face, an abnormally wide space between the eyes, a broad nasal bridge, a highly arched palate, a fold of the skin over the inner corner of the eyes, and large ears with …

How common is Pallister-Killian mosaic syndrome?

Pallister-Killian syndrome (PKS) is an extremely rare genetic disorder that is present at birth. The prevalence has been estimated to be 1 in 20,000; however, it is likely that PKS is underdiagnosed due to the difficulty of making a cytogenetic diagnosis from a blood test.

What is a ring chromosome abnormality?

A ring chromosome is an aberrant chromosome whose ends have fused together to form a ring. Ring chromosomes were first discovered by Lilian Vaughan Morgan in 1926. A ring chromosome is denoted by the symbol r in human genetics and R in Drosophila genetics.

What is Mosaic syndrome?

Mosaic Turner syndrome (TS) is a condition in which cells inside the same person have different chromosome packages. Mosaic TS can affect any cell in the body. Some cells have X chromosomes and some don’t.

What are the symptoms of Pallister Killian mosaic syndrome?

Pallister-Killian mosaic syndrome is characterized by extremely weak muscle tone (hypotonia) in infancy and early childhood, intellectual disability, distinctive facial features, sparse hair, areas of unusual skin coloring (pigmentation), and other birth defects 1).

What kind of genetic disorder is Pallister Killian syndrome?

Pallister–Killian syndrome (also tetrasomy 12p mosaicism or Pallister mosaic aneuploidy syndrome) is an extremely rare genetic disorder occurring in humans. Pallister–Killian occurs due to the presence of the anomalous extra isochromosome 12p, the short arm of the twelfth chromosome. This leads to the development of tetrasomy 12p.

Which is the most severe form of mosaic syndrome?

The most severe cases involve birth defects that are life-threatening in early infancy. However, several affected people have had milder features, including mild intellectual disability and less noticeable physical abnormalities.

Where does the chromosomal change in mosaic syndrome occur?

The chromosomal change responsible for the disorder typically occurs as a random event during the formation of reproductive cells (eggs or sperm) in a parent of the affected individual, usually the mother. Affected individuals have no history of the disorder in their families.