|
|
Down Syndrome
Alternate Names : Trisomy 21
Definition Down syndrome is a chromosome abnormality, usually due to an extra copy of the 21st chromosome. This syndrome usually, although not always, results in mental retardation and other conditions.
Overview, Causes, & Risk Factors
In most cases, Down syndrome is caused by an extra chromosome 21. It is the most common single cause of human birth defects, with an occurence in 1 out of every 660 births.
Children with Down syndrome have a widely recognized characteristic appearance. The head may be smaller than normal (microcephaly) and abnormally shaped. Prominent facial features include a flattened nose, protruding tongue, and upward slanting eyes. The inner corner of the eyes may have a rounded fold of skin (epicanthal fold) rather than coming to a point. The hands are short and broad with short fingers and often have a single crease in the palm (simian crease). Retardation of normal growth and development is typical and most affected children never reach average adult height.
Congenital heart defects are frequently present in Down syndrome children. Early mortality is often a result of cardiac abnormalities. Gastrointestinal abnormalities such as esophageal atresia (obstruction of the esophagus) and duodenal atresia (obstruction of the duodenum) are also relatively common. Obstruction of the gastrointestinal tract may require major surgery shortly after birth. Children with Down syndrome also have a higher than average incidence of acute lymphocytic leukemia (ALL).
Today's Top News Stories | | Seniors Having More Sex Than Ever - Jul 09, 2008, 09:00 Study finds big jump in number of those over 70 who are 'doing it' | | Men Often Not Told of Severity of Wife's Cancer - Jul 09, 2008, 09:00 Study finds almost 40% say docs never said condition was terminal until near death. | | Gene Activity May Explain Deadlier Breast Cancers Among Younger Women - Jul 09, 2008, 09:00 Study finds more than 350 common sets of genes in patients under 45. | | Breast-Conserving Surgery Leaves Many Cancer Patients Disappointed - Jul 09, 2008, 09:00 Poor aesthetic outcome after lumpectomy linked to depression, fear, study finds. | | A Blood Marker Could Spot Diabetes Risk - Jul 08, 2008, 16:00 Higher levels of fetuin-A were linked to later disease development, study found
. |
|
Jump to another section
Definition Down Syndrome Overview, Causes, & Risk Factors Down Syndrome Symptoms & Signs Down Syndrome Prevention Down Syndrome Diagnosis & Tests Down Syndrome Treatment Down Syndrome Prognosis Down Syndrome Complications Down Syndrome Support Groups Calling Your Health Care Provider
Topics that might be of interest to you Diseases & Conditions
Acute Lymphocytic Leukemia Esophageal Atresia Imperforate Anus Mental Retardation Otitis
Tests & Exams
Amniocentesis ECG Echocardiogram Karyotyping X-Ray
Other Topics
Delayed Growth Hearing Loss Hypotonia Incidence Iris Vision Problems
Review Date : 8/19/2003
Reviewed By : Douglas R. Stewart, M.D., Division of Medical Genetics, Hospital of the University of Pennsylvania, Philadelphia, PA. Review provided by VeriMed Healthcare Network.
|
|