| The de Lange Syndrome is most commonly referred to as the Cornelia de Lange syndrome (CdLS) but is also known as the Brachmann-de Lange syndrome. Dr. Cornelia de Lange first described this syndrome in 1933 although Dr. Brachmann wrote about a similar child in 1916. CdLS is a syndrome with estimated birth prevalence between 1:10,000 and 1:30,000 live births. There are no definitive biochemical or chromosome markers for the diagnosis of this syndrome although research is ongoing to find the genetic cause. At the present time diagnosis is made on the basis of clinical observations. The most frequently observed facial characteristics include thin, downturned lips; low set ears; long eyelashes; and eyebrows that meet in the middle. Other characteristics often associated with this syndrome include delayed growth and small stature; language delay, even in the more mildly affected; microcephaly (small head size); hirsutism (excessive body hair); and simian creases. Low birth weight is typically a feature of this syndrome with the average birth weight being five pounds and one ounce. Individuals may also be tactilely defensive or show a lack of sensitivity to pain. There is often a characteristic vocal quality in the crying of babies, which has been described as feeble or low-pitched. Although mental retardation is typically present in this syndrome, there are some people who have normal or slightly below normal intelligence. | 
