Pallister–Killian syndrome

Pallister–Killian syndrome
Synonyms	Tetrasomy 12p mosaicism, Pallister mosaic syndrome
Pronounce	N/A
Specialty	N/A
Symptoms	Hypotonia, intellectual disability, seizures, hearing loss, vision problems, sparse hair, pigmentation differences
Complications	N/A
Onset	Congenital
Duration	Lifelong
Types	N/A
Causes	Tetrasomy of the short arm of chromosome 12
Risks	Advanced maternal age
Diagnosis	Karyotype analysis, FISH (fluorescence in situ hybridization)
Differential diagnosis	Down syndrome, Prader-Willi syndrome, Angelman syndrome
Prevention	N/A
Treatment	Symptomatic and supportive care
Medication	N/A
Prognosis	Variable, depends on severity of symptoms
Frequency	Rare
Deaths	N/A

Pallister-Killian syndrome is a rare, multisystemic genetic disorder characterized by a variety of physical abnormalities. The syndrome is caused by the presence of additional genetic material from chromosome 12 (tetrasomy 12p) in some cells of the body.

Symptoms and Signs

The symptoms of Pallister-Killian syndrome can vary greatly from one person to another. Common symptoms include:

• Intellectual disability
• Hypotonia (low muscle tone)
• Seizures
• Hearing loss
• Vision problems
• Skin pigmentation changes
• Congenital heart defects
• Cleft palate
• Diaphragmatic hernia

Causes

Pallister-Killian syndrome is caused by the presence of an extra copy of the short arm of chromosome 12 (tetrasomy 12p) in some cells of the body. This extra genetic material is not inherited from the parents, but occurs as a random event during the formation of reproductive cells or in early fetal development.

Diagnosis

Diagnosis of Pallister-Killian syndrome is often based on the presence of characteristic signs and symptoms. Genetic testing can confirm the diagnosis by identifying the extra genetic material from chromosome 12.

Treatment

There is no cure for Pallister-Killian syndrome. Treatment is symptomatic and supportive, and may include physical therapy, special education, and treatment for specific symptoms such as seizures and heart defects.

Prognosis

The prognosis for individuals with Pallister-Killian syndrome varies depending on the severity of symptoms. Some individuals may have a normal lifespan, while others may have life-threatening complications.

See also

• Genetic disorders
• Chromosome abnormalities
• Rare diseases