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Found Trisomy 9 times.

Displaying results 1 to 10.

1. Down syndrome (Down's syndrome, trisomy 21).
An uncommon (1 in 1000 births) congenital disorder in which a person is born with three copies of chromosome 21. It is more common among children born to mothers over the age of 35. People with this disorder have physical and mental retardation to varying degrees and typically have facial defects, vision, respiratory and cardiac problems. This disorder was formerly known as mongolism.

2. Down's syndrome (Down syndrome, Trisomy 21)
Physical characteristics of a person with Down's syndrome include small and short head, flat nasal bridge, reddish cheeks, dry lips, large, protruding tongue, small ears, epicanthal folds, and short neck. Mental retardation and hypotonia are also major symptoms, the degree of which varies with individuals. There is also a high incidence of congenital heart diseases and duodenal atresia . With good support, persons with this syndrome can develop their full potential. An Alzheimer -like dementia often occurs in the fourth and fifth decades and leads to a shortened life expectancy. The chromosomal abnormality is diagnostic. In 95% of cases, trisomy 21 is present (one extra chromosome 21), and in the rest which has the usual 46 chromosomes present, there is an abnormal translocation involving chromosome 21.

3. Edward's Syndrome ( Edwards' syndrome, trisomy 18, trisomy E)
A congenital disorder caused by a baby having an extra copy of chromosome 18 (three instead of the normal two). Characteristics of the disorder include a large number of different malformed organs and malformed physical features of the face and skeletal structure. In most cases, the child dies before it is born; 90% of babies born live die within a year of birth. Symptoms may be less severe when the trisomy occurs after fertilization during mitosis in the zygote (10% of cases), than when the trisomy occurs during the meiosis which produced the egg or sperm (90% of cases).

4. Genomic formula
The method used to identify the number of sets of chromosome s within a cell or organism (i.e. its ploidy ). Each set is designated "n" so one set is n is haploid , two sets is 2n is diploid , three sets is 3n is triploid , four sets is 4n is tetraploid, etc. Also, 2n+1 is known as trisomy (i.e. two full sets plus a third copy of one of the chromosomes).

5. Klinefelter syndrome (XXY trisomy)
A genetic syndrome in many mammals caused by the presence of an extra X chromosome in the male (normally XY) karyotype . In humans, this syndrome is characterized by small testes, feminine appearance, sterility (except in the case of genetic mosaics) and possibly mental retardation. In domestic cats, male calicos always have this genetic condition.

6. Patau syndrome (trisomy 13)
A congenital disorder caused by a person having an extra (three copies of) chromosome 13; this disorder causes severe eye, brain and heart defects and is also characterized by a cleft lip and cleft palate.

7. Pierre Robin syndrome
Pierre Robin syndrome is characterized by cleft palate, small mouth, and protruding tongue. It is inherited as an autosomal recessive condition. There is also an X-linked form and associated with trisomy 18 and other genetic syndromes.

8. Trisomy
A cell or organism which has two full sets of chromosome s (is thus diploid ), but has a third copy of one of its chromosomes. Organisms which are trisomic generally also suffer from physical and/or mental disabilities or abnormalities.

9. Trisomy
A condition where a cell has an extra chromosome .

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