Editing Human genetic enhancement (section)

=== Physical appearance ===
{{See also|Morphological freedom}}
The exploration of challenges in understanding the effects of gene alterations on phenotypes, particularly within natural genetic diversity, is highlighted. Emphasis is placed on the potential of systems biology and advancements in [[Genotype|genotyping]]/[[Phenotype|phenotyping]] technologies for studying complex traits. Despite progress, persistent difficulties in predicting the influence of gene alterations on phenotypic changes are acknowledged, emphasizing the ongoing need for research in this area.<ref>{{cite journal | vauthors = Benfey PN, Mitchell-Olds T | title = From genotype to phenotype: systems biology meets natural variation | journal = Science | volume = 320 | issue = 5875 | pages = 495–7 | date = April 2008 | pmid = 18436781 | pmc = 2727942 | doi = 10.1126/science.1153716 | bibcode = 2008Sci...320..495B }}</ref>

Some congenital disorders (such as [[:Category:Congenital disorders of musculoskeletal system|those affecting the muscoskeletal system]]) may affect physical appearance, and in some cases may also cause physical discomfort. Modifying the genes causing these congenital diseases (on those diagnosed to have mutations of the gene known to cause these diseases) may prevent this.

''- Phenotypic Impacts of CRISPR-Cas9 Editing in Mice Targeting the Tyr Gene:''

In a comprehensive [[CRISPR]]-[[Cas9]] study on gene editing, the Tyr gene in mice was targeted, seeking to instigate genetic alterations. The analysis found no off-target effects across 42 subjects, observing modifications exclusively at the intended Tyr locus. Though specifics were not explicitly discussed, these alterations may potentially influence non-defined aspects, such as coat color, emphasizing the broader potential of gene editing in inducing diverse phenotype changes.<ref>{{cite journal | vauthors = Parikh BA, Beckman DL, Patel SJ, White JM, Yokoyama WM | title = Detailed phenotypic and molecular analyses of genetically modified mice generated by CRISPR-Cas9-mediated editing | journal = PLOS ONE | volume = 10 | issue = 1 | pages = e0116484 | date = 2015-01-14 | pmid = 25587897 | pmc = 4294663 | doi = 10.1371/journal.pone.0116484 | bibcode = 2015PLoSO..1016484P | doi-access = free }}</ref>

Also changes in the myostatin gene<ref name="Haisma">{{cite journal | vauthors = Gavish B, Gratton E, Hardy CJ | title = Adiabatic compressibility of globular proteins | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 80 | issue = 3 | pages = 750–4 | date = February 1983 | pmid = 6572366 | pmc = 393457 | doi = 10.1073/pnas.80.3.750 | doi-access = free | bibcode = 1983PNAS...80..750G }}</ref> may alter appearance.