A genetic mutation associated with childhood hereditary baldness has been identified by an US-led study. Researchers discovered a mutation in the APCDD1 gene was common to three families of Italian or Pakistani origin, who were affected by hereditary hypotrichosis simplex (HSS). This disease results in the shrinking of hair follicles and thinning of the hair - a process that also occurs in male pattern baldness.
APCDD1 inhibits the Wnt pathway - a network of proteins involved in carrying information to a cell's nucleus - that is already known to be involved in hair loss in mice. 'We have at last made a connection between Wnt signalling and human hair disease that is highly significant… This is the first mutation in a Wnt inhibitor that deregulates the pathway in a human hair disease', said Dr Angela M Christiano, who led the study at Columbia University Medical Center, New York.
The APCDD1 gene is located in a region of chromosome 18 previously associated with several forms of hair loss, including androgenetic alopecia and male pattern baldness. In both of these diseases, as in HSS, thin hair growth called 'peach fuzz' replaces long, thicker hair.
Although this latest study highlights a possible role for APCDD1 in a process common to all of these diseases, Dr Christiano said their results had limitations: 'It is important to note that while these two conditions [HSS and male pattern baldness] share the same physiologic process, the gene we discovered for hereditary hypotrichosis does not explain the complex process of male pattern baldness'.
But the study does suggest some new lines of investigation for scientists developing hair loss treatments. According to Dr Chistiano: ' manipulating the Wnt pathway may have an effect on hair follicle growth - for the first time in humans. And unlike commonly available treatments for hair loss that involve blocking hormonal pathways, treatments involving the Wnt pathway would be non-hormonal, which may enable many more people suffering from hair loss to receive such therapies'. The research was published in Nature this week.