Editing Autosome (section)

== Autosomal genetic disorders ==
[[File:Autosomal recessive inheritance.gif|thumb|An illustration of the inheritance pattern and phenotypic effects of an autosomal recessive gene.]]
Autosomal genetic disorders can arise due to a number of causes, some of the most common being [[nondisjunction]] in parental germ cells or [[Mendelian inheritance]] of deleterious alleles from parents. Autosomal genetic disorders which exhibit Mendelian inheritance can be inherited either in an [[autosomal dominant]] or recessive fashion.<ref name=":0" /> These disorders manifest in and are passed on by either sex with equal frequency.<ref name=":0">{{Cite web|title = human genetic disease|url = https://www.britannica.com/science/human-genetic-disease|website = Encyclopædia Britannica|access-date = 2015-10-16|url-status = live|archive-url = https://web.archive.org/web/20151013183225/https://www.britannica.com/science/human-genetic-disease|archive-date = 2015-10-13}}</ref><ref>{{cite journal |last1=Chial |first1=Heidi |year=2008 |title=Mendelian Genetics: Patterns of Inheritance and Single-Gene Disorders |journal=Nature Education |volume=1 |issue=1 |page=63 |url=https://www.nature.com/scitable/topicpage/mendelian-genetics-patterns-of-inheritance-and-single-966/ }}</ref> Autosomal dominant disorders are often present in both parent and child, as the child needs to inherit only one copy of the deleterious [[allele]] to manifest the disease. Autosomal recessive diseases, however, require two copies of the deleterious allele for the disease to manifest. Because it is possible to possess one copy of a deleterious allele without presenting a disease phenotype, two phenotypically normal parents can have a child with the disease if both parents are carriers (also known as [[heterozygote]]s) for the condition.

Autosomal [[aneuploidy]] can also result in disease conditions. Aneuploidy of autosomes is not well tolerated and usually results in miscarriage of the developing fetus. Fetuses with aneuploidy of gene-rich chromosomes—such as [[Chromosome 1 (human)|chromosome 1]]—never survive to term,<ref name=":1">{{Cite book|publisher = Humana Press|date = 2005-01-01|isbn = 978-1-58829-300-8|pages = 133–164|first1 = Jin-Chen C.|last1 = Wang|editor-first = Steven L.|editor-last = Gersen|editor-first2 = Martha B. Keagle|editor-last2 = MEd|doi = 10.1385/1-59259-833-1:133|title = The Principles of Clinical Cytogenetics|chapter = Autosomal Aneuploidy}}</ref> and fetuses with aneuploidy of gene-poor chromosomes—such as [[Chromosome 21 (human)|chromosome 21]]— are still miscarried over 23% of the time.<ref name="pmid16634111">{{cite journal |last1=Savva |first1=George M. |last2=Morris |first2=Joan K. |last3=Mutton |first3=David E. |last4=Alberman |first4=Eva |title=Maternal age-specific fetal loss rates in Down syndrome pregnancies |journal=Prenatal Diagnosis |date=June 2006 |volume=26 |issue=6 |pages=499–504 |doi=10.1002/pd.1443 |pmid=16634111 |s2cid=34154717 }}</ref> Possessing a single copy of an autosome (known as a monosomy) is nearly always incompatible with life, though very rarely some monosomies can survive past birth. Having three copies of an autosome (known as a trisomy) is far more compatible with life, however. A common example is [[Down syndrome]], which is caused by possessing three copies of [[Chromosome 21 (human)|chromosome 21]] instead of the usual two.<ref name=":1" />

Partial aneuploidy can also occur as a result of [[Chromosomal translocation|unbalanced translocations]] during meiosis.<ref>{{Cite web|title = Translocation - Glossary Entry|url = http://ghr.nlm.nih.gov/glossary=translocation|website = Genetics Home Reference|date = 2015-11-02|access-date = 2015-11-08|url-status = live|archive-url = https://web.archive.org/web/20151209181233/http://ghr.nlm.nih.gov/glossary=translocation|archive-date = 2015-12-09}}</ref> Deletions of part of a chromosome cause partial monosomies, while duplications can cause partial trisomies. If the duplication or deletion is large enough, it can be discovered by analyzing a karyogram of the individual. Autosomal translocations can be responsible for a number of diseases, ranging from [[cancer]] to [[schizophrenia]].<ref name="pmid19556891">{{cite journal |last1=Strefford |first1=Jonathan C. |last2=An |first2=Qian |last3=Harrison |first3=Christine J. |title=Modeling the molecular consequences of unbalanced translocations in cancer: Lessons from acute lymphoblastic leukemia |journal=Cell Cycle |date=31 October 2014 |volume=8 |issue=14 |pages=2175–2184 |doi=10.4161/cc.8.14.9103 |pmid=19556891 |doi-access=free }}</ref><ref name="pmid11973326">{{cite journal |last1=Klar |first1=Amar J S |title=The chromosome 1;11 translocation provides the best evidence supporting genetic etiology for schizophrenia and bipolar affective disorders |journal=Genetics |date=2002 |volume=160 |issue=4 |pages=1745–1747 |doi=10.1093/genetics/160.4.1745 |pmid=11973326 |pmc=1462039 }}</ref> Unlike single gene disorders, diseases caused by aneuploidy are the result of improper [[gene dosage]], not nonfunctional gene product.<ref name="pmid22974302">{{cite journal |last1=Disteche |first1=Christine M. |title=Dosage Compensation of the Sex Chromosomes |journal=Annual Review of Genetics |date=15 December 2012 |volume=46 |issue=1 |pages=537–560 |doi=10.1146/annurev-genet-110711-155454 |pmid=22974302 |pmc=3767307 }}</ref>