trisomy 21


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Related to trisomy 21: trisomy 21 syndrome

trisomy 21

trisomy 21

trisomy 21

Down syndrome, mongolism Pediatrics A chromosomal dysgenesis caused by partial or complete duplication of all or part of chromosome 21 appears 3 times; in some only some cells contain the chromosomal defect–ie, mosaicism Clinical MR, microcephaly, short stature, a characteristic facial dysmorphia–flat hypoplastic facies, short/flat nose, upward slanting eyes–Mongolian slant; inner corner of the eyes often has a rounded fold of skin–epicanthal fold; small, low-set ears, thickened, protruding and fissured tongue, joint laxity, pelvic dysplasia, broad hands and feet with shortened digits, a single transverse palmar or simian crease, lenticular opacification, cardiac defects–eg, PDA, endocardial cushion defects, Fallot's tetralogy, esophageal atresia, duodenal atresia, muscle spasms, ↑ risk of ALL, retardation of growth and development is typical; most never reach average adult height Risk of DS ↑ with maternal age–0.7/1000 births ≤ age 30; 34.6/1000 ≥ age 45 Prognosis Compatible with long-term survival Incidence 1:900. See Maternal age.

trisomy 21

chromosomal abnormality (three rather than two chromosome 21) causing development of type of Down's syndrome

Patient discussion about trisomy 21

Q. Can Down syndrome occur again? A few years ago, at the age of 32 my sister gave birth to a child that was diagnosed with Down syndrome. Now, at the age of 37 she's pregnant again. Can she have another baby with Down? Does the fact she has a baby with Down means she has higher risk for a second baby with Down?

A. - Older women especially after 35 years
- Previuosly child with Down Syndrome

Video link
http://www.thedoctorsvideos.com/video/585/Downs-Syndrome

DrMFK

Q. assessment of down syndrom

A. down syndrome is a very easy diagnosis - it just need a chromosome check and seeing 3 (instead 2) chromosomes number 21. -

http://learn.genetics.utah.edu/content/disorders/whataregd/down/

Q. what does enlarged heart mean? is it linked to down syndrome? My wife is 16 weeks pregnant. we did a prenatal US and we were told that the baby hes an enlarged heart and that we are advised to do amniocentesis. A friend of mine had a baby with down syndrome, and he was toled that if they have done this procedure, the doctors could have find it on time and abort the pregnancy. Is there a clear connection between the enlarged hart and the fact that the doctor advised us to do this procedure to down syndrome?

A. Down syndrome is associated with several kinds of heart problems. those problems can cause an enlarged heart but usually it will appears as a post-natal complication.
The protocol that most obstetrics use is that if there is anything abnormal in the US there is an automatic referral to an amniocentesis procedure.
the US has a lot of false alarms, so they must check with the more accurate procedure.

More discussions about trisomy 21
References in periodicals archive ?
First-trimester screening for trisomy 21 combining biochemistry and ultrasound at individually optimal gestational ages.
Chromosome-selective sequencing of maternal plasma cell-free DNA for first-trimester detection of trisomy 21 and trisomy 18.
The chromosomal analysis were undertaken in 22 cases, out of which 20 (91%) cases had free trisomy 21, 1 case had trisomy 21 with translocation (46, XY, der (21;21)(q10;q10),+21), and 1 case had mosaic trisomy 21 (47, XY,+21/46, XY) [Table 2].
For younger women (<40 yr), traditional sequential screening provided the highest detection of all abnormalities and was the optimal testing strategy, while cfDNA was preferable for women aged 40 or older, given the higher prevalence of trisomy 21.
The primary outcome was the area under the receiver-operating-characteristic (ROC) curve for trisomy 21.
The karyotype report of the down's syndrome revealed primary trisomy 21 in 39 cases (78%), mosaic trisomy 21 in 6 patients (12%), Down's syndrome primary amenorrhea in 3 cases (6%) whereas translocation46, XY, t (14:21) was the least common which was 2 cases (4%) (Table 7).
6,7) Occasionally, the finding of TAM may even be the first indication that a patient has trisomy 21.
In the 73 buccal swab samples, for 71 of them the trisomy 21 was molecularly confirmed.
The new research also found trisomy 21 neurons in the brains of children with what, until now, was thought to be an unrelated neurodegenerative disease (Niemann Pick type C), caused by a mutation affecting cholesterol physiology.
The following groups were included in the study:-Huntington's disease and trisomy 21.
The companies have agreed to collaborate in the development and launch of a trisomy 21 laboratory developed test and other aneuploidies testing in Germany, Austria, Switzerland, and Liechtenstein, with the potential for additional launches in other countries.