Is trisomy 9 genetic?
Mosaic trisomy 9 is usually not inherited . It often occurs sporadically as a random event during the formation of the reproductive cells (egg and sperm) or as the fertilized egg divides.
What is the phenotype of trisomy 18?
The phenotypic characteristics of trisomy 18 are intrauterine growth restriction, hypertonia, prominent occiput, small mouth, micrognathia, pointy ears, short sternum, horseshoe kidney, and flexed fingers, with the index finger overlapping the third finger and the fifth finger overlapping the fourth.
What disease is associated with chromosome 9?
Chromosome 9, Trisomy 9p is a rare chromosomal disorder in which a portion of chromosome 9 appears three times (trisomy) rather than twice in cells of the body. The trisomy may involve a portion of the short arm (9p), the entire short arm, or the short arm and a segment of the long arm (9q).
What are the clinical characteristics of trisomy 9p Syndrome?
Most of the clinical characteristics distinctive of the trisomy 9p syndrome are seen also in other trisomies involving more or less of the number 9 chromosome. From these observations it is determined that the crucial determinants of the classical features of this syndrome lie within the distal half of the number 9 short arm.
What is the history of trisomy 9p?
The chromosomal abnormality was originally reported in the medical literature in1970. Trisomy 9p was first proposed as a distinct syndrome with characteristic symptoms and findings in 1975.
What is an example of a 9p chromosome?
For example, the short arm of chromosome 9 includes bands 9p11 to 9p24, and the long arm includes bands 9q11 to 9q34. In trisomy 9p, the trisomy (or duplicated material) may involve a portion of the short arm (9p), the entire short arm, or the short arm and a portion of the long arm (9q) of chromosome 9.
What is tetrasomy 9p (chromosome 9)?
Chromosome 9, tetrasomy 9p is a rare chromosomal disorder in which the short arm of chromosome 9 (9p) is present four times (tetrasomy) rather than twice in all or some cells of the body.