What is 9p duplication?
Chromosome 9p duplication is a chromosome abnormality that occurs when there is an extra copy of genetic material on the short arm (p) of chromosome 9. The severity of the condition and the signs and symptoms depend on the size and location of the duplication and which genes are involved.
What are the symptoms of monosomy 9p?
Characteristic symptoms and findings include mental retardation; distinctive malformations of the skull and facial (craniofacial) region, such as an abnormally shaped forehead (i.e., trigonocephaly), upwardly slanting eyelid folds (palpebral fissures), and unusually flat midfacial regions (midfacial hypoplasia); …
What is 9p deletion syndrome?
9p Deletion Syndrome is a very rare chromosome abnormality that reportedly occurs in 1 in 50,000 births. It is characterized by a portion of the “p” (or short end of the 9th chromosome) being deleted or missing. The area where chromosome material is deleted is called a “breakpoint.”
What causes trisomy 9p?
In some cases, trisomy 9p appears to result from a balanced chromosomal rearrangement in one of the parents. In others, it is thought to arise from spontaneous (de novo) errors very early in embryonic development that occur for unknown reasons (sporadically).
How common is trisomy 9p?
As of 2013, more than 150 cases have been reported in the medical literature since the disorder was first described in 1970. Trisomy 9p is the fourth most common type of trisomy after trisomy 21 (Down syndrome), trisomy 18 (Edwards’s syndrome) and trisomy 13 (Patau syndrome).
What causes monosomy 9p?
Chromosome 9p deletion is a chromosome abnormality that occurs when there is a missing (deleted) copy of genetic material on the short arm (p) of chromosome 9.
What population is affected by monosomy 9p?
Chromosome 9p deletion syndrome occurs 1 in 50,000 births. Half of the cases occur sporadically, while the other half of cases result from parent translocations or the parent having deletion as well.
What causes monosomy 9P?
Monosomy 9p (also known as Alfi’s Syndrome or simply 9P-) is a rare chromosomal disorder in which some DNA is missing or has been deleted on the short arm region, “p”, of one of the 9th Chromosomes (9p22. 2-p23). This deletion either happens de novo or a result of a parent having the chromosome abnormality.
What is monosomy 9p?
Monosomy 9p is a rare chromosomal anomaly characterized by psychomotor developmental delay, facial dysmorphism (trigonocephaly, midface hypoplasia, upslanting palpebral fissures, dysplastic small ears, flat nasal bridge with anteverted nostrils and long philtrum, micrognathia, choanal atresia, short neck), single …
Can Alfi’s syndrome be prevented?
It may be true also for glaucoma, choanal atresia and omphalocele: all these defects are more frequent among patients having an additional chromosomal imbalance. The vital prognosis is relatively favorable, especially in patients without serious heart defects. There is no cure for this syndrome.
How many genes does chromosome 9 have?
800 to 900 genes
Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. Chromosome 9 likely contains 800 to 900 genes that provide instructions for making proteins.
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).
Is Alfi’s syndrome inherited?
In most patients the syndrome is the result of a sporadic chromosomal mutation, but in ~15% of families it is caused by balanced abnormalities (usually translocations) in one of the parents. That is why parental cytogenetic examination is necessary especially for families planning to have more children.