Male Pattern Baldness Risk and Your Genetics

By the ExomeDNA Research Team | Last reviewed May 2026

Male pattern baldness (androgenetic alopecia) is a common form of hair loss driven by a combination of androgens and hereditary factors, producing a characteristic pattern of thinning at the crown and temples. Twin studies estimate heritability above 80 percent, and genome-wide research has identified hundreds of associated variants across the genome. Below: which genes show the strongest signals, what the research establishes about mechanism, and what evidence suggests about the interplay between genetics and modifiable factors.

What is Male Pattern Baldness?

Male pattern baldness, clinically called androgenetic alopecia, is a progressive reduction in hair follicle size driven by the action of dihydrotestosterone (DHT) on genetically susceptible follicles. DHT — a potent androgen derived from testosterone — shortens the anagen (active growth) phase of the hair cycle, causing follicles to produce progressively thinner and shorter hairs until they eventually become inactive.

The condition follows a characteristic pattern described by the Hamilton-Norwood scale: beginning with a receding hairline at the temples, progressing to thinning at the crown, and in advanced cases leading to extensive hair loss over the top of the scalp while the sides and back remain relatively unaffected. This pattern reflects the differential sensitivity of follicles at different scalp locations to DHT.

Androgenetic alopecia is extremely common: studies suggest it affects approximately 50 percent of men by age 50 and increases in prevalence with advancing age. The condition is largely determined by inherited factors, though the precise combination of variants differs between individuals.

The genetics behind Male Pattern Baldness

Male pattern baldness has one of the strongest heritabilities among common physical traits, with twin studies consistently estimating heritability above 80 percent. Genome-wide association studies have identified hundreds of loci contributing to this heritability, reflecting a highly polygenic architecture where many variants each contribute a small incremental effect.

TMEM131L — transmembrane protein 131-like — shows the strongest individual association signal in genome-wide analyses of male pattern baldness. The region near TMEM131L on chromosome 4 carries a high-confidence signal identified by L2G-based gene mapping, suggesting a plausible functional connection to follicle biology, though the precise mechanism remains under investigation.

ZNF462 (zinc finger protein 462) is a transcription factor located on chromosome 9. The variant near ZNF462 shows one of the strongest association signals in this trait's genetic architecture. Transcription factors regulate the expression of downstream genes; ZNF462's role in follicular biology is an active area of research.

ZHX3 (zinc fingers and homeoboxes 3) encodes a transcriptional repressor. Located near a credible genetic signal on chromosome 20, ZHX3 may influence follicle cycling through regulation of gene expression programs in dermal papilla cells — the specialized cells that orchestrate follicle activity.

FGF5 (fibroblast growth factor 5) is among the better-characterized genes in the male pattern baldness signal set. FGF5 is known to promote the transition of hair follicles from the anagen (growth) phase to the catagen (regression) phase. Higher FGF5 activity shortens the growth cycle. Variants near FGF5 are associated with hair length and cycle dynamics across species and are a plausible contributor to androgenetic alopecia through altered follicle cycling.

LAMC3 (laminin subunit gamma 3) encodes a component of the extracellular matrix surrounding hair follicles. Laminins are structural proteins that support the basement membrane, and variants near LAMC3 have been identified in the genetic architecture of hair traits including baldness, suggesting that follicular structural support is part of the genetic story.

AFF3, identified in the reference gene set for this trait, encodes a tissue-restricted transcriptional activator preferentially expressed in lymphoid tissue but with broader functions in transcriptional regulation. Its appearance in male pattern baldness signals reflects the complex, multisystem genetic architecture of this polygenic trait.

Beyond these named loci, hundreds of additional variants across the genome contribute to the highly polygenic architecture of male pattern baldness — a reflection of the many cellular processes involved in maintaining a healthy hair follicle cycle. (Kichaev et al. 2019)[1]

Genome-wide association analyses have identified hundreds of genetic variants associated with male pattern baldness, with the strongest signals near TMEM131L, ZNF462, ZHX3, and FGF5 — together reflecting regulation of follicle cycling, transcriptional control, and androgen sensitivity. (Kichaev et al. 2019)^[1]

What the research says

Research base: Moderate. Male pattern baldness has been studied in large genome-wide association studies with well-replicated top signals. The overall heritability estimate is robust, and the polygenic nature of the trait is well-established. However, the specific mechanistic roles of most individual loci — particularly those beyond FGF5 and the androgen receptor pathway — remain an active area of research.

Kichaev et al. (2019) applied polygenic functional enrichment methods to improve statistical power in genome-wide association analyses, contributing to the identification of genetic signals for complex traits including androgenetic alopecia. This analytic approach helps distinguish true genetic signals from noise in highly polygenic traits where individual effect sizes are small. (Kichaev et al. 2019)[1]

The moderate confidence tier for this trait reflects two things: the individual loci outside the top few signals carry small effects and are less individually replicated, and the specific biological mechanisms connecting most GWAS loci to follicle biology have not yet been fully established. The overall polygenic architecture and direction of effect are well-supported; the mechanistic pathway for most individual genes is not.

For a full description of how ExomeDNA evaluates and ranks genetic signals, see our methodology page for the complete statistical approach.

Twin study estimates consistently place the heritability of male pattern baldness above 80 percent, making it one of the most heritable common physical traits — and one where genetics provides meaningful but not complete explanatory power. (Kichaev et al. 2019)^[1]

How Male Pattern Baldness affects you

The experience of androgenetic alopecia varies widely. Some people notice a receding hairline beginning in their twenties; others maintain dense hair into their fifties before significant thinning begins. The rate of progression, the pattern, and the ultimate extent of hair loss are all influenced by the specific combination of genetic variants present, their interaction with androgen levels, and aging biology.

Genetics explains a large share of this variation but not all of it. Androgen levels — including testosterone and its conversion to DHT — are themselves partly heritable and partly determined by body composition, metabolic health, and other factors. The combination of androgen-receptor sensitivity variants and androgen production variants shapes how an individual's follicles respond to DHT over time.

It is worth noting that the ExomeDNA result reflects common inherited variation identified in population studies. Rare syndromic causes of hair loss — such as those associated with hormonal disorders — are distinct from the polygenic variation captured here and require clinical evaluation.

Working with your profile

What research suggests about factors that interact with genetics

Several factors are known to interact with genetic predisposition for hair loss:

1. Androgen levels and metabolic health — DHT production depends on testosterone levels and 5-alpha-reductase enzyme activity. Metabolic conditions that affect androgen metabolism may amplify the expression of genetic predisposition.
2. Age — The penetrance of androgenetic alopecia increases strongly with age. Most people with a high genetic loading for hair loss show significant progression by their fifties if not earlier.
3. Nutritional status — Iron deficiency and deficiencies in other micronutrients have been associated with hair loss in observational research. Correcting nutritional deficiencies addresses a modifiable contributor that operates alongside genetics.
4. Scalp health — Chronic scalp inflammation and dermatological conditions can accelerate follicular miniaturization in genetically susceptible individuals.
5. Medical treatments — Finasteride (a 5-alpha-reductase inhibitor) and minoxidil have demonstrated efficacy in slowing androgenetic alopecia progression in clinical trials. These are the only interventions with robust clinical trial evidence. Neither eliminates genetic predisposition but both can slow or partially reverse miniaturization.
6. Hair transplantation — Surgical redistribution of follicles from the hormonally resistant areas (sides and back) to affected areas is an established option for suitable candidates.

None of these factors eliminate genetic predisposition, but the evidence suggests the rate of progression and the degree of loss can be influenced.

Related traits and genes

Male pattern baldness shares genetic architecture with several related traits in your ExomeDNA profile, reflecting the overlap between follicle biology, hormone regulation, and physical trait genetics.

Related traits in Physical Traits:

• Hair color genetics — shared follicular and pigmentation biology
• Hair texture — overlapping keratin and structural follicle gene signals
• Hair thickness — follicle diameter and cycling genetics overlap

Cross-category related traits:

• Testosterone levels — androgen pathway genetics intersects with baldness susceptibility
• Skin aging — shared extracellular matrix and structural protein gene signals

FGF5 and LAMC3 are examples of genes that appear in both hair trait and broader physical trait architectures, reflecting the shared biology of follicular and skin structural biology.

Frequently asked questions

Is male pattern baldness purely inherited from the mother's side? No. This is a common misconception. Male pattern baldness is a polygenic trait influenced by hundreds of variants inherited from both parents across multiple chromosomes. While some older research pointed to the androgen receptor gene on the X chromosome (inherited from the mother) as a major contributor, genome-wide studies have since identified hundreds of additional loci on other chromosomes inherited from either parent.

If my father went bald young, does that mean I will too? A father who went bald young suggests a higher genetic loading for androgenetic alopecia in the family — but because hair loss genetics is polygenic and both parents contribute variants, a father's pattern is one data point among many. Two brothers with the same father can have substantially different outcomes depending on which combination of variants each inherited.

What is the difference between male pattern baldness and other types of hair loss? Androgenetic alopecia follows a characteristic patterned progression driven by DHT and genetic susceptibility of follicles. Other causes of hair loss — alopecia areata (autoimmune), telogen effluvium (diffuse stress-related shedding), and traction alopecia (mechanical) — have different biological mechanisms and are not captured by this genetic trait result. If your hair loss pattern is diffuse, sudden, or atypical, a dermatology evaluation is appropriate.

Do women get male pattern baldness? Women experience a related condition called female pattern hair loss (androgenetic alopecia in women), which shares some genetic signals but typically presents as diffuse thinning over the crown rather than the patterned recession characteristic of male androgenetic alopecia. The ExomeDNA result for this trait reflects the male-pattern phenotype studied in genome-wide research cohorts.

Can I slow down hair loss if I have a high genetic score? The available clinical evidence supports that finasteride and minoxidil can slow androgenetic alopecia progression and, in some people, partially restore density. These treatments work by addressing the androgen-sensitivity mechanism rather than the underlying genetics. They do not change your genetic variants, but they reduce the biological signal those variants respond to.

References

1. Kichaev G, Bhatia G, Loh PR, et al. (2019). Leveraging Polygenic Functional Enrichment to Improve GWAS Power. American Journal of Human Genetics. PMID: 30595370.

--- Data sources: GWAS Catalog (NHGRI-EBI, accessed 2026-05-24) · Open Targets Platform (CC0 1.0, accessed 2026-05-24) · ClinVar (NCBI, accessed 2026-05-24)

This page is published by the ExomeDNA Research Team. Last reviewed: 2026-05-24.