[ugh]

Gevonden via http://www.ergogenics.org.





http://www.eurekalert.org/pub_releas...-tth052005.php

Public release date: 20-May-2005


Prof. Markus Nöthen
University of Bonn
Tendency to hair loss inherited from the mother

Probably the genetic variant results in more androgen receptors in the scalp. "Our findings permit two explanations," Axel Hillmer from Prof. Nöthen's team explains. "Either more androgen receptors are formed among the men affected, or the variant of the receptor which develops as a result of the genetic change is more stable and is not broken down so quickly. Both mechanisms can lead to the effect of the androgens becoming greater, which in turn brings about hair loss."



The findings are also interesting for the aspect of how hair loss is inherited. The gene for the androgen receptor lies on the x chromosome. Men always inherit the x chromosome from their mother. In many cases men therefore take after their grandfather on their mother's side rather than their father. However, this defect is not simply caused by one gene: "We have indications that other genes are involved which are independent of the parents' sex," Prof. Nöthen stresses. The hereditary defect can therefore sometimes also be passed on directly from father to son.

Zoals ook vermeld, is AGA polygenic; er zijn dus vaak meerdere genen betrokken, waaronder een ook wat van de vader.
Het onderzoeksteam is bezig andere betrokken genen te identificeren.

De abstract, thx Laurens
http://www.ncbi.nlm.nih.gov/entrez/q...657&query_hl=2

Am J Hum Genet. 2005 May 18;77(1) [Epub ahead of print]Links

Genetic Variation in the Human Androgen Receptor Gene Is the Major Determinant of Common Early-Onset Androgenetic Alopecia.

Hillmer AM, Hanneken S, Ritzmann S, Becker T, Freudenberg J, Brockschmidt FF, Flaquer A, Freudenberg-Hua Y, Jamra RA, Metzen C, Heyn U, Schweiger N, Betz RC, Blaumeiser B, Hampe J, Schreiber S, Schulze TG, Hennies HC, Schumacher J, Propping P, Ruzicka T, Cichon S, Wienker TF, Kruse R, Nothen MM.

Department of Genomics, Life and Brain Center, University of Bonn, Bonn, Germany. markus.noethen@uni-bonn.de.

Androgenetic alopecia (AGA), or male-pattern baldness, is the most common form of hair loss. Its pathogenesis is androgen dependent, and genetic predisposition is the major requirement for the phenotype. We demonstrate that genetic variability in the androgen receptor gene (AR) is the cardinal prerequisite for the development of early-onset AGA, with an etiological fraction of 0.46. The investigation of a large number of genetic variants covering the AR locus suggests that a polyglycine-encoding GGN repeat in exon 1 is a plausible candidate for conferring the functional effect. The X-chromosomal location of AR stresses the importance of the maternal line in the inheritance of AGA.

PMID: 15902657 [PubMed - as supplied by publisher]