Mosaic trisomy 14
- Mosaic trisomy chromosome 14
- Trisomy 14 mosaicism
Your QuestionMy daughter has been recently diagnosed with trisomy 14 mosaic. She is 2 months old. I have been told that this is a very rare disease with only upwards of 20 cases worldwide. I am looking for more information on this disease so that I can best meet my child's needs.
We have identified the following information that we hope you find helpful. If you still have questions, please contact us.
Questions on this page
- intrauterine growth restriction
- feeding difficulties
- failure to thrive
- some degree of developmental delay or intellectual disability
- slightly asymmetrical growth
- abnormal skin pigmentation
- structural defect(s) of the heart such as tetralogy of Fallot
- minor genital abnormalities in boys such as undescended testes
- distinctive facial characteristics such as a prominent forehead; widely spaced eyes; a broad nasal bridge; low-set, malformed ears; a small lower jaw; a large mouth and thick lips; eye abnormalities; or abnormality of the roof of the mouth (palate)
Skeletal abnormalities have also been reported and include dislocation of the hips; overlapping of certain fingers or toes; and/or other features.
Most cases of mosaic trisomy 14 appear to result from random errors in the separation of chromosomes (nondisjunction) -- either during the division of the egg or sperm in one of the parents, or during cell division after fertilization. There have been some reports in which it may have occurred due to other phenomenon, such as uniparental disomy or the formation of an isochromosome. Uniparental disomy is when an affected individual inherits both copies of a chromosomal pair from one parent, rather than one copy from each parent. An isochromosome is an abnormal chromosome with identical arms on each side of the centromere.
Unique has a leaflet on their Web site that contains additional descriptions and illustrations of how mosaic trisomy 14 may occur. Click here to view the leaflet.
- Chromosome 14, Trisomy Mosaic. NORD. May 26, 2008; http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/999/viewAbstract. Accessed 11/13/2012.
- Trisomy 14 mosaicism. Unique. 2008; http://www.rarechromo.org/information/Chromosome%2014/Trisomy%2014%20mosaicism%20FTNW.pdf. Accessed 11/14/2012.