Genetics and other factors in the aetiology of female pattern hair loss

Abstract

Pattern hair loss is the most common form of hair loss in both women and men. Male pattern hair loss, also termed male androgenetic alopecia (M-AGA), is an androgendependent trait that is predominantly genetically determined. Androgen-mediated mechanisms are probably involved in female pattern hair loss (FPHL) in some women but the evidence is less strong than in M-AGA; other non-androgenic pathways, including environmental influences, may contribute to the aetiology. Genome-wide association studies have identified several genetic loci for M-AGA and have provided better insight into the underlying biology. However, the role of heritable factors in and it has long been assumed that FPHL shares the same aetiology;hence, the term "female androgenetic alopecia" is often applied to this condition. However, the role of androgens in causing FPHL is less clear than in men. The genetic studies performed so far have not led to any firm conclusions but rather suggest different pathways for M-AGA and FPHL.In this review, we summarize what is known about the aetiology of FPHL and its relationship to M-AGA. Our main focus is on the results of genetic studies performed within the last decade. We also discuss the role of endocrine and other factors in the pathogenesis. | PREVALENCEPublished data on the prevalence of FPHL show some variation between studies, perhaps reflecting the difficulty in classifying mild forms of the condition. However, all show an increasing prevalence with age. Studies in women of white European ethnicity in the USA, [2] UK [3] and Australia [4] record a prevalence of 3%-12% in the third decade, rising to 14%-28% in the sixth decade and 29%-56%

Significant relationship between temporal hair loss and other scalp areas in female pattern hair loss

“…The temporal scalp may also be affected like the frontoparietal area in FPHL because of their same embryologic background . Our study has significant implications for clarifying the correlation of each sites’ hair loss, though previous studies have suggested the possibility of hair loss in the occipitotemporal area …”

“…13 Our study has significant implications for clarifying the correlation of each sites' hair loss, though previous studies have suggested the possibility of hair loss in the occipitotemporal area. 4,5,[14][15][16][17][18][19] We used the BASP classification, which has been proposed as a new method for evaluating PHL of male and female patients. 9 BASP classification assesses the involvement area by four basic types (L, M, C and U) and two special types (V and F).…”

Evaluation of Hair Density and Hair Diameter in the Adult Thai Population Using Quantitative Trichoscopic Analysis

“…is is unlike the case in patients suffering from male AGA or female pattern hair loss (FPHL), in whom hair density and hair diameter decrease differently. Multiple studies suggest that male AGA is caused by numerous polymorphisms associated with androgen-related genes, while FPHL may have a different etiology and may not be linked to a hormone-driven mechanism [24].…”

Novel <b><i>ABCD1</i></b> Gene Mutation in Adrenomyeloneuropathy with Hypoplasia and Agenesis of the Corpus Callosum

“…The changeable level of testosterone might exert some roles in the formation of androgenetic alopecia. In addition, no causative variants in CYP17, SRD5A1, SRD5A2, and HR genes associated with alopecia were found by the exome sequencing in this family [16]. Although the hair loss was not specific for AMN, it should be borne in mind that recognition of such an association between alopecia and ABCD1 mutations would likely aid the diagnosis of AMN.…”