#Science infographic on down syndrome free#

Each offers varying levels of sensitivity and specificity. Table 2 describes the different chromosomal characteristics of Down syndrome.Ī wide variety of screening test options exist in the first and second trimester using maternal serum and ultrasonography. The chance of recurrence for families with an affected child depends on many factors and vary greatly, from 1% in most families to 100% in some circumstances. People with mosaicism may be more mildly affected than people with complete trisomy 21 or translocation chromosome 21, but this is not always the case, and their condition may include any of the associated medical problems and may be indistinguishable from trisomy 21.

In the remaining 1% to 2% of people with the Down syndrome phenotype, a mix of 2 cell lines is present: 1 normal and the other with trisomy 21. If the child has a translocation, the parents should be offered a karyotype to determine whether the translocation is familial or de novo. Approximately three-quarters of these unbalanced translocations are de novo, and the remainder result from translocation inherited from a parent. In ∼3% to 4% of people with the Down syndrome phenotype, the extra chromosomal material is the result of an unbalanced translocation between chromosome 21 and another acrocentric chromosome, usually chromosome 14 or 21.

#Science infographic on down syndrome free#

In ∼96% of children with Down syndrome, the condition is sporadic because of nonfamilial trisomy 21, in which there are 47 chromosomes with the presence of a free extra chromosome 21. Antithyroid antibody positive (Hashimoto thyroiditis incidence dependent on age)ĭown syndrome 26 times greater in patients with Moyamoya than Down syndrome in live births