Trisomy 16: Difference between revisions

Revision as of 21:00, 9 February 2025

A genetic disorder caused by an extra copy of chromosome 16

Trisomy 16 is a chromosomal disorder characterized by the presence of an extra copy of chromosome 16. It is one of the most common chromosomal abnormalities observed in miscarriages and is rarely compatible with life.

Genetics

Trisomy 16 occurs when there are three copies of chromosome 16 instead of the usual two. This can happen due to nondisjunction during meiosis, where chromosomes fail to separate properly. The extra chromosome can be present in all cells (full trisomy 16) or in some cells (mosaic trisomy 16).

Clinical Features

Full trisomy 16 is typically not compatible with life and is a common cause of first-trimester miscarriages. Mosaic trisomy 16, where only some cells have the extra chromosome, can result in a live birth but is associated with various developmental and health issues. These may include growth retardation, congenital heart defects, and other anomalies.

Diagnosis

Trisomy 16 can be diagnosed prenatally through procedures such as chorionic villus sampling (CVS) or amniocentesis. These tests analyze fetal cells to detect chromosomal abnormalities.

Prognosis

The prognosis for trisomy 16 depends on whether the condition is full or mosaic. Full trisomy 16 usually results in miscarriage, while mosaic trisomy 16 can lead to a range of outcomes depending on the extent and distribution of the trisomic cells.

Related pages

References

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-'''Trisomy 16''' is a chromosomal abnormality in which there are three copies of chromosome 16 rather than two. It is the most common trisomy leading to miscarriage and the second most common chromosomal cause of it, closely following [[X-chromosome monosomy]].
+{{Short description|A genetic disorder caused by an extra copy of chromosome 16}}
+{{Use dmy dates|date=October 2023}}
-==Causes==
+'''Trisomy 16''' is a chromosomal disorder characterized by the presence of an extra copy of chromosome 16. It is one of the most common chromosomal abnormalities observed in miscarriages and is rarely compatible with life.
-Trisomy 16 is usually caused by [[nondisjunction]], a process in which cells divide improperly, resulting in an extra chromosome. This can occur in either the sperm or the egg that forms the fetus. The exact cause of nondisjunction is unknown, but it is believed that both genetic and environmental factors may play a role.
-==Symptoms==
+==Genetics==
-The symptoms of trisomy 16 vary depending on whether the individual has full or mosaic trisomy 16. Full trisomy 16, which means that every cell in the body has an extra chromosome 16, is not compatible with life and usually results in miscarriage in the first trimester. Mosaic trisomy 16, in which only some cells have an extra chromosome 16, can result in a range of symptoms including growth retardation, [[congenital heart defects]], and developmental delays.
+Trisomy 16 occurs when there are three copies of chromosome 16 instead of the usual two. This can happen due to nondisjunction during meiosis, where chromosomes fail to separate properly. The extra chromosome can be present in all cells (full trisomy 16) or in some cells (mosaic trisomy 16).
+[[File:Chromosome_16.svg|thumb|right|Diagram of chromosome 16]]
+==Clinical Features==
+Full trisomy 16 is typically not compatible with life and is a common cause of first-trimester miscarriages. Mosaic trisomy 16, where only some cells have the extra chromosome, can result in a live birth but is associated with various developmental and health issues. These may include growth retardation, congenital heart defects, and other anomalies.
 ==Diagnosis==
-Trisomy 16 can be diagnosed through several methods. [[Prenatal testing]] such as [[amniocentesis]] or [[chorionic villus sampling]] can detect the condition before birth. After birth, a [[karyotype]] test, which analyzes the number and structure of chromosomes in a cell, can confirm the diagnosis.
+Trisomy 16 can be diagnosed prenatally through procedures such as [[chorionic villus sampling]] (CVS) or [[amniocentesis]]. These tests analyze fetal cells to detect chromosomal abnormalities.
-==Treatment==
+[[File:Chorionic_villi_-_high_mag.jpg|thumb|right|Micrograph of chorionic villi, which can be sampled for prenatal diagnosis]]
-There is no cure for trisomy 16. Treatment focuses on managing symptoms and may include physical therapy, special education, and surgeries to correct physical abnormalities.
 ==Prognosis==
-The prognosis for individuals with mosaic trisomy 16 varies widely depending on the severity of symptoms. Some individuals may live relatively normal lives, while others may have severe disabilities.
+The prognosis for trisomy 16 depends on whether the condition is full or mosaic. Full trisomy 16 usually results in miscarriage, while mosaic trisomy 16 can lead to a range of outcomes depending on the extent and distribution of the trisomic cells.
+==Related pages==
+* [[Chromosomal disorder]]
+* [[Nondisjunction]]
+* [[Prenatal diagnosis]]
-==See also==
+==References==
-* [[Chromosome abnormality]]
+{{Reflist}}
-* [[Genetic disorder]]
-* [[Patau syndrome]]
-* [[Edwards syndrome]]
 [[Category:Genetic disorders]]
 [[Category:Chromosomal abnormalities]]
-{{genetics-stub}}
-{{medicine-stub}}