Monosomy 14

Monosomy 14
Specialty	Medical genetics
Symptoms	Intellectual disability, coloboma, stunted growth, microcephaly, neural tube defects, heart defects
Duration	Lifelong
Types	Full, mosiac
Causes	Nondisjunction
Diagnostic method	Karyotype
Prognosis	Incompatible with life

Monosomy, with the presence of only one chromosome (instead of the typical two in humans) from a pair, which affects chromosome 14. Fetuses with monosomy 14 are not viable. ^[1] Only mosaic cases typically survive and these usually present with severe symptoms such as intellectual disability, ocular colobomata, microcephaly, and seizures. Organ malformations are also associated due to the chromosome 14 having several genes for organ development, including heart defects, and brain problems. In full monosomy 14 in all cells, the total number of chromosomes is 45 instead of 46. Many are stillborn if the pregnancy does progress to term. The prognosis is generally poor even in mosaic form and the symptoms include intellectual disability, small head, ocular problems, seizures, and heart malformations. They may have kidney issues, ventricular underdevelopment, or brain defects. Their eyes, heart, brain, and head are far less developed than fetuses with two copies of chromosome 14. The severe gene dosage imbalance is common in these fetuses. Some signs include

• • Intellectual disabilities
  • Coloboma
  • Stunted growth
  • Microcephaly with ocular problems
  • Neural tube defects
  • Heart defect

^{[2] [3]}

References

1. Ginsburg, David; Gelehrter, Thomas D.; Collins, Francis S. (1998). Principles of medical genetics . Baltimore: Williams & Wilkins. pp.  169. ISBN   0-683-03445-6.
2. McConnell V, Derham R, McManus D, Morrison PJ (July 2004). "Mosaic monosomy 14: clinical features and recognizable facies". Clin. Dysmorphol. 13 (3): 155–60. doi:10.1097/01.mcd.0000126137.29572.59. PMID   15194951. S2CID   22523296.
3. Cantú ES, Thomas IT, Frias JL (September 1989). "Unusual cytogenetic mosaicism involving chromosome 14 abnormalities in a child with an MR/MCA syndrome and abnormal pigmentation". Clin. Genet. 36 (3): 189–95. doi:10.1111/j.1399-0004.1989.tb03187.x. PMID   2676269. S2CID   40718643.