Vitiligo is a disease with a global prevalence estimated between 0.5 and 2%. Over the past few decades, several hypotheses have been proposed regarding the causes of this dermatosis, and various sources attribute vitiligo to a hereditary origin. Read on to discover if scientific literature truly mentions genetic predispositions to developing vitiligo.
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Is vitiligo a hereditary disease?
Summary
Published November 19, 2024,
updated on November 19, 2024,
by
Pauline, Chemical Engineer
—
5 min read
A Genetic Component in Vitiligo?
Explained by a selective loss of melanocytes, the cells that synthesize melanin, the pigment that gives skin its color, vitiligo manifests visually as the appearance of white patches on the skin. If the body areas affected by vitiligo no longer have melanin, the melanoblasts, precursors of melanocytes located deeper in the skin, are still present. Their activation by certain vitiligo treatments allows for skin repigmentation. For a long time, vitiligo was considered a psychosomatic pathology. However, it is now known that it is largely based on an autoimmune mechanism, with a multifactorial origin.
Although vitiligo is not strictly speaking a hereditary disease, there are familial predispositions to developing it.
≈ 20 %
Individuals affected by vitiligo have at least one first-degree relative suffering from this disease.
7 to 10
There is a significantly higher risk of developing vitiligo if a first-degree relative has this disease.
Extensive research has been conducted to elucidate the genetic factors contributing to the onset of vitiligo. Over 50 susceptibility genes have been associated with the disease, such as HLA, CTLA4, NLRP1, and TYR. Individuals carrying one or more variants of these genes are at a higher risk of developing the disease, but they will not necessarily be affected. The majority of loci, that is, the positions of genes on the chromosomes, associated with vitiligo code for genes involved in immune regulation, apoptosis, and melanocyte biology.
It is intriguing to note that the genes involved in the onset of vitiligo are not the same in all parts of the world. Thus, some are more commonly found in European populations, while others are more prevalent in China, Japan, or India. A few examples of these peculiarities are presented in the table below.
| Chromosome | Gene | Population |
|---|---|---|
| 1p13.2 | PTPN22 | Arabic, European, Indian |
| 1q24.3 | FASLG | Chinese, European |
| 6p22.1 | HLA-A1 | Chinese, European, Japanese |
| 6p22.1 | BTNL2 - HLA-DRA | Indian |
| 1p31.3-p32.2 | FOXD3 | European |
| 22q12 | XBP1 | Chinese |
| Xp11.23 | CCDC22-FOXP3-GAGE | Chinese, European, Indian |
Loci de susceptibilité au vitiligo selon certaines régions du monde.
Source : SPRITZ R. & al. The Genetic Basis of Vitiligo. Journal of Investigative Dermatology (2021).
For a number of these genes, causal genetic variants have been discovered, providing significant insight into the biological mechanisms underlying the risk of vitiligo attributable to these genes. Furthermore, together, the corresponding proteins define a functional network suggesting a general pathobiological pathway of damage to melanocytes, activation of immune cells, and targeting and apoptosis of melanocytes.
The genetic component of vitiligo has been particularly highlighted during genome-wide association studies, or GWAS in English. These studies rely on the analysis of specific genetic variations in the genome to identify those most often linked to a disease. Genome-wide association studies are based on the comparison of DNA from two large groups: one group composed of patients, referred to as the examined group, and one group composed of healthy subjects, or control group. They have been particularly useful in identifying the different susceptibility alleles for vitiligo.
Sources
NATH S. & al. Genetic epidemiology of vitiligo: multilocus recessivity cross-validated. American journal of human genetics (1994).
CZAJKOWSKI R. & al. Current aspects of vitiligo genetics. Advances in Dermatology and Allergology (2014).
EZZEDINE K. & al. Vitiligo: A Review. Dermatology (2020).
SPRITZ R. & al. The Genetic Basis of Vitiligo. Journal of Investigative Dermatology (2021).
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