Alexander disease Alexander disease is an extremely rare, usually progressive and fatal, neurological disorder. It is one of a group of disorders, called leukodystrophies (diseases

What is Li-Fraumeni syndrome Li-Fraumeni syndrome is a rare inherited disorder that greatly increases the risk of developing several types of cancer, particularly in children

Mosaic Down syndrome About two to four percent of people with Down syndrome (trisomy 21) have mosaic Down syndrome, where only some of the cells

Pallister Killian mosaic syndrome Pallister-Killian mosaic syndrome also called Pallister-Killian syndrome or PKS, is a rare sporadic developmental disorder caused by mosaic tissue-limited tetrasomy of

Smith Lemli Opitz syndrome Smith-Lemli-Opitz syndrome is a variable genetic disorder (multiple congenital anomaly or intellectual disability syndrome) that affects many parts of the body

Peutz Jeghers syndrome Peutz-Jeghers syndrome is a rare inherited disease that is characterized by the development of noncancerous growths called hamartomatous polyps (benign tumors made

What is omphalocele An omphalocele is also called exomphalos, is a birth defect in which an infant's intestine, liver and other abdominal organs are outside

What is leukodystrophy Leukodystrophies make up a group of rare heritable myelin disorders affecting the white matter of the central nervous system (the brain and

Snoring in children It’s common for children to snore when they have a cold, but frequent snoring in young children and toddlers is not normal,

Headaches in children Headaches are common in children and adolescents. A headache is a symptom of pain in the area of the head, face or