Feingold syndrome is a disorder that affects many parts of the body. The signs and symptoms of this condition vary among affected individuals, even among members of the same family.
Individuals with Feingold syndrome have characteristic abnormalities of their fingers and toes. Almost all people with this condition have a specific hand abnormality called brachymesophalangy, which refers to shortening of the second and fifth fingers. Other common abnormalities include fifth fingers that curve inward (clinodactyly), underdeveloped thumbs (thumb hypoplasia), and fusion (syndactyly) of the second and third toes or the fourth and fifth toes.
People with Feingold syndrome are frequently born with a blockage in part of their digestive system called gastrointestinal atresia. In most cases, the blockage occurs in the esophagus (esophageal atresia) or in part of the small intestine (duodenal atresia). Additional common features of Feingold syndrome include an unusually small head size (microcephaly), a small jaw (micrognathia), a narrow opening of the eyelids (short palpebral fissures), and mild to moderate learning disability. Less often, affected individuals have hearing loss, impaired growth, and kidney and heart abnormalities.
Feingold syndrome appears to be a rare condition, although its exact prevalence is unknown.
Mutations in the MYCN gene cause Feingold syndrome. This gene provides instructions for making a protein that plays an important role in the formation of tissues and organs during embryonic development. Studies in animals suggest that this protein is necessary for normal development of the limbs, heart, kidneys, nervous system, digestive system, and lungs. The MYCN protein regulates the activity of other genes by attaching (binding) to specific regions of DNA. On the basis of this action, this protein is called a transcription factor.
Mutations in the MYCN gene that cause Feingold syndrome prevent one copy of the gene in each cell from producing any functional MYCN protein. As a result, only half the normal amount of this protein is available to control the activity of specific genes during embryonic development. It remains unclear how a reduced amount of the MYCN protein causes the specific features of Feingold syndrome.
- microcephaly-mesobrachyphalangy-tracheoesophageal fistula (MMT) syndrome
- microcephaly-oculo-digito-esophageal-duodenal (MODED) syndrome
- oculo-digito-esophagoduodental (ODED) syndrome