What is the role of genetics in back hair growth?

While the specific genes involved in back hair growth are not fully understood, research suggests a significant hereditary component. Patterns of body hair growth have been found to run in families.

What does the 23andMe back hair report tell me?

The 23andMe back hair report can provide insights into whether you are genetically predisposed to have back hair. However, this report only covers a fraction of the genes that may influence back hair, and other factors like age and hormones also play a role.

Back Hair in Men: 23andMe Trait of the Day Explained

Why does Hair Grow on the Back?

Hair growth is a normal part of human physiology and is influenced by various factors including age, hormones, and genetics. The presence of hair on various parts of the body, including the back, is an evolutionary trait. Body hair, or androgenic hair, is the terminal hair that develops on the human body during and after puberty.

In men, androgenic hair grows thickly on the chest and abdomen, and sometimes on the back and shoulders. This hair growth pattern is influenced by hormones, specifically androgens like testosterone, which increase during puberty and trigger the development of secondary sexual characteristics.

Genetics of Back Hair

The distribution and density of body hair, including back hair, in humans is a complex trait influenced by several genetic and hormonal factors.

Genetics and Androgens

One key player in the determination of hair growth patterns is the androgen receptor gene (AR). This gene provides instructions for making a protein that binds to hormones like testosterone and dihydrotestosterone, which regulate hair growth. Variations in the AR gene can influence the density and distribution of body hair, including back hair.

Other Genetic Factors

While the AR gene plays a significant role, it’s not the only gene involved. Hair growth is a complex process regulated by numerous genes, many of which remain unidentified. These genes could influence various aspects of hair growth, including the timing of hair growth cycles, the density of hair follicles, and the responsiveness of hair follicles to hormones.

Genome-wide association studies (GWAS) have identified several genetic variants associated with male pattern baldness and hair growth patterns. These variants are located in or near genes that play roles in hair growth and development, including HDAC9, TARDBP, and WNT10A. However, more research is needed to fully understand how these genetic variants might influence back hair growth.

Sex Differences in Hair Growth

Sex differences in back hair growth are also believed to have a genetic basis. Men are generally more likely to have back hair than women, and this difference is likely due, in part, to differences in the genes that regulate sex hormones. However, the exact genetic mechanisms underlying these sex differences remain unclear.

In summary, while genetics plays a role in back hair growth, it’s a complex trait influenced by numerous factors, and much about the genetics of back hair remains to be discovered.

The 23andMe Back Hair Report

The 23andMe back hair report is a part of their health and ancestry service, providing information about certain genetic variants associated with the likelihood of having back hair.

This report is generated based on the presence or absence of specific genetic variants associated with back hair in the individual’s DNA. The report does not provide a definitive answer on whether someone will have back hair or not but rather indicates if an individual has the genetic markers that make it more or less likely.

The variants used by 23andMe for this report were identified through genome-wide association studies (GWAS). These studies scan the genomes of many people to find genetic variants associated with certain traits. In the case of back hair, 23andMe has identified certain variants that are more common in people who report having back hair compared to those who do not.

However, it’s important to understand that this report does not consider all possible genetic variants that could influence back hair, and it does not take into account other factors like age, hormone levels, or ethnicity, which can also influence hair growth. So while the report can provide some insight into the genetic factors that contribute to back hair, it should not be used to predict with certainty whether someone will or will not have back hair.

Additionally, all 23andMe reports should be interpreted with the help of a healthcare provider or genetic counselor to understand what the results mean in the context of your overall health and family history.

Also Read: Top 10 Questions on 23andMe Answered

Summary

Why does hair grow on the back?

Hair growth on the back, like other parts of the body, is a normal part of human physiology and is influenced by various factors including age, hormones, and genetics.
What is the role of genetics in back hair growth?

While the specific genes involved in back hair growth are not fully understood, research suggests a significant hereditary component. Patterns of body hair growth have been found to run in families.
What does the 23andMe back hair report tell me?

The 23andMe back hair report can provide insights into whether you are genetically predisposed to have back hair. However, this report only covers a fraction of the genes that may influence back hair, and other factors like age and hormones also play a role.

References

Sato T, Sonoda T, Itami S, Takayasu S. Predominant expression of human zeta-class glutathione S-transferases in the cytoplasm of the secretory cells of eccrine sweat glands. Journal of Investigative Dermatology. 2002 Apr;118(4):728-30.
Randall VA. Hormones and hair growth: variations in androgen receptor content of dermal papilla cells cultured from human and red deer (Cervus elaphus) hair follicles. Journal of Investigative Dermatology. 1994 Jul;103(1):116S-121S.
Paus R, Cotsarelis G. The biology of hair follicles. New England Journal of Medicine. 1999 Aug 12;341(7):491-7.