Gene linked to hereditary childhood baldness

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.