Editing Chinese Americans (section)

== Genetics ==

=== Studies on the genetics of Chinese Americans ===
A research on the whole genome patterns of common DNA variation in different human populations (African-American, Asian-American and European American) finds some common [[single-nucleotide polymorphism]]s (SNPs) in these three populations with diverse ancestry.<ref>{{cite journal |last1=Hinds |first1=David A. |last2=Stuve |first2=Laura L. |last3=Nilsen |first3=Geoffrey B. |last4=Halperin |first4=Eran |last5=Eskin |first5=Eleazar |last6=Ballinger |first6=Dennis G. |last7=Frazer |first7=Kelly A. |last8=Cox |first8=David R. |title=Whole-Genome Patterns of Common DNA Variation in Three Human Populations |journal=Science |date=18 February 2005 |volume=307 |issue=5712 |pages=1072–1079 |doi=10.1126/science.1105436 |pmid=15718463 |bibcode=2005Sci...307.1072H |citeseerx=10.1.1.115.3580 |s2cid=27107073 }}</ref> In the samples of Han Chinese in America, 74% of the total SNPs have two alleles, and majority of the segregating SNPs have a [[minor allele frequency]] (MAF) greater than 10%. Another noticeable point is that MAFs show similar distributions in European-American and Han Chinese populations. Besides, rarer haplotype is found to be absent in the samples of Han Chinese, and they also possess a high level of redundancy.{{citation needed|date=September 2018}}

A study analyzing East Asian Genetic Substructure using genome-wide SNP arrays is carried out with greater than 200,000 genotypes from people of East Asian ancestry.<ref>{{cite journal |last1=Tian |first1=Chao |last2=Kosoy |first2=Roman |last3=Lee |first3=Annette |last4=Ransom |first4=Michael |last5=Belmont |first5=John W. |last6=Gregersen |first6=Peter K. |last7=Seldin |first7=Michael F. |title=Analysis of East Asia Genetic Substructure Using Genome-Wide SNP Arrays |journal=PLOS ONE |date=5 December 2008 |volume=3 |issue=12 |pages=e3862 |doi=10.1371/journal.pone.0003862 |pmid=19057645 |pmc=2587696 |bibcode=2008PLoSO...3.3862T |doi-access=free }}</ref> The continental populations are from the Human Genome Diversity Panel (Cambodian, Yi, Daur, Mongolian, Lahu, Dai, Hezhen, Miaozu, Naxi, Oroqen, She, Tu, Tujia, Naxi, Xibo, and Yakut), HapMap (Han Chinese and Japanese), as well as East Asian or East Asian-American subjects of Vietnamese, Korean, Filipino and Chinese ancestry. A clear understanding of the genetic substructure of any population helps in the studies of complex diseases, as well as the design and execution of association tests. Results of this study have identified markers that can not only reduce type 1 errors in future genetic disease studies, but also identify homogeneous groups and hence make this study more powerful.{{Citation needed|date=February 2024}}

The group of Chinese Americans in the same study consists of subjects with origins from North China, South China and Taiwan. This group is paired with Han Chinese from Beijing, and results indicate that the population differentiation values was small (<0.0025). There is substantially less genetic substructure between Han Chinese and Chinese American, compared with that between Han Chinese, Japanese and Korean groups, yet there is still a substructure in principal component, according to the split half reliability test.{{Citation needed|date=February 2024}}

Another study aiming to estimate cardiometabolic risk profile of Chinese adults with diabetes is also useful to reveal the personal genomics of Chinese Americans.<ref>{{cite journal |last1=Ding |first1=Lin |last2=Xu |first2=Yu |last3=Wang |first3=Limin |last4=Xu |first4=Min |last5=Jiang |first5=Yong |last6=Zhang |first6=Mei |last7=Li |first7=Yichong |last8=Lu |first8=Jieli |last9=Wang |first9=Tiange |last10=Dai |first10=Meng |last11=Zhang |first11=Di |last12=Wang |first12=Weiqing |last13=Zhao |first13=Wenhua |last14=Wang |first14=Linhong |last15=Bi |first15=Yufang |last16=Ning |first16=Guang |author17=2010 China Non-communicable Disease Surveillance Group |title=The cardiometabolic risk profile of Chinese adults with diabetes: A nationwide cross-sectional survey |journal=Journal of Diabetes and Its Complications |date=January 2017 |volume=31 |issue=1 |pages=43–52 |doi=10.1016/j.jdiacomp.2016.10.023 |pmid=27838099 }}</ref> In this study, all subjects are over 18 years old and non-institutionalized. Results derived from a complex, multistage, probability sampling design show that 12,607 out of 98,658 Chinese adults are suffering from diabetes, based on the criteria of 2010 American Diabetes Association. In addition, the study reaches a conclusion that for those Chinese adults defined with diabetes, cardiometabolic risk factors are highly prevalent, including metabolic syndrome, systolic blood pressure that is higher than 140mmHg, low fruit and vegetable intake, low-density lipoprotein cholesterol that is higher than 110&nbsp;mg/dL.{{Citation needed|date=February 2024}}

=== Diabetes ===
The circumstance of the Asian American population is informative in a way that some knowledge about Chinese Americans can be inferred from it. The statistics of diabetes in Asian American population reveals that approximately 10% of the entire population are diabetic, and in which 90–95% are type 2 diabetes.<ref>{{Cite news|url=http://blogs.plos.org/publichealth/2012/11/27/overcoming-the-obstacles-of-diagnosing-diabetes-in-asian-americans/|title=Overcoming the obstacles of diagnosing diabetes in Asian Americans {{!}} Public Health|date=27 November 2012|newspaper=Public Health|access-date=4 December 2016|archive-date=20 December 2016|archive-url=https://web.archive.org/web/20161220055311/http://blogs.plos.org/publichealth/2012/11/27/overcoming-the-obstacles-of-diagnosing-diabetes-in-asian-americans/|url-status=live}}</ref> The current situation is that there are some challenges in diagnosing diabetes in many Asian Americans. The main obstacle is that many clinical features along with risks factors associated with diabetes are obtained from studies that focus on Caucasian populations, which might result in misdiagnoses between type 1 and type 2 diabetes for Asian Americans. In fact, the reason why classic features of type 1 and type 2 diabetes in America might not apply to Asian American population is about shared absence of common HLA DR-DQ genotype, low prevalence of positive anti-islet antibodies and low BMI in both types of diabetes.<ref>{{cite journal |last1=Hsu |first1=William C. |last2=Okeke |first2=Eyiuche |last3=Cheung |first3=Sophia |last4=Keenan |first4=Hillary |last5=Tsui |first5=Tracy |last6=Cheng |first6=Kyle |last7=King |first7=George L. |title=A Cross-Sectional Characterization of Insulin Resistance by Phenotype and Insulin Clamp in East Asian Americans with Type 1 and Type 2 Diabetes |journal=PLOS ONE |date=2 December 2011 |volume=6 |issue=12 |pages=e28311 |doi=10.1371/journal.pone.0028311 |pmid=22164267 |pmc=3229556 |bibcode=2011PLoSO...628311H |doi-access=free }}</ref>

Some other studies have pointed out that for people of Asian descent and without diabetes, their insulin resistance levels are higher than non-diabetic people of Caucasian descent. Thus, Asian Americans are relatively more predisposed to develop type 2 diabetes. This suggests that insulin resistance, rather than body mass index (BMI) should be targeted while making diagnoses. A potential biomarker to identify diabetes in young Asian-American population is adipocyte fatty acid binding protein that has a strong association with insulin resistance but is independent of adiposity. Nevertheless, more research studies should be carried out in order to confirm such finding. With further applying the above outcome on the population of Chinese Americans, it is rational that there is a higher tendency for type 2 diabetes among this group of people, who also face the challenge of correct diagnosis in America.{{Citation needed|date=February 2024}}

=== Mental illness ===
[[File:Chinese patient.jpg|thumb|Chinese American psychiatric patient, 1915]]

Genetic mental illness is stigmatized in China. A study compares the attitude of Chinese Americans towards mental illness with genetic causes and that of European American. It finds out that there is a perception of eugenics existing among Chinese Americans.<ref>{{cite journal |last1=WonPat-Borja |first1=Ahtoy J. |last2=Yang |first2=Lawrence H. |last3=Link |first3=Bruce G. |last4=Phelan |first4=Jo C. |title=Eugenics, genetics, and mental illness stigma in Chinese Americans |journal=Social Psychiatry and Psychiatric Epidemiology |date=January 2012 |volume=47 |issue=1 |pages=145–156 |doi=10.1007/s00127-010-0319-7 |pmid=21079911 |pmc=3141094 }}</ref> Consequently, in order to reduce the stigma in the society, more efforts should be devoted to this population.{{Citation needed|date=February 2024}}

=== Stigma and eugenics ===
The journal launched by the above study highlights the idea of genetic essentialism, namely, genes are largely deterministic of individual characteristics and behavior. There is a separation between the normal and the deviant, which drives the process of stigma labeling. On the other hand, since genetic diseases can be passed on from one generation to another, some mental illnesses are shared in a family, stigmatizing all members involved. Another viewpoint relevant to genetic essentialism is that, since genes are perceived by the common people as difficult to modify, genetic mental illness is likely to persist, and so is the stigma. As a result, the mindset of many Chinese Americans is formulated as diseases with genetic causes being more serious than those without.{{Citation needed|date=February 2024}}

The same journal also delivers some hypotheses made on the basis of the long history of eugenics in China. First, Chinese Americans are more in favor of eugenic policies than European Americans. Secondly, more stigma would be generated towards genetic attributions of any diseases in Chinese American population. China used to implement restrictions on marriage licenses to people with genetic illnesses, which has made the attitude of Chinese Americans towards premarital genetic screening more supportive, especially when facing a chance of genetic defects. Moreover, from the perspective of this group of people, knowing whether a marriage partner has family history of mental illness with genetic basis is fairly important.{{Citation needed|date=February 2024}}