Identification of a U2HR gene mutation in Turkish families with Marie Unna hereditary hypotrichosis.

Marie Unna hereditary hypotrichosis (MUHH) is an autosomal dominant form of isolated alopecia. The disorder is characterized by the absence or scarcity of scalp hair, eyebrows and eyelashes at birth. Coarse wiry hair begins to grow during childhood, but this is followed by progressive hair loss, which usually begins around puberty. A recent study identified mutations in U2HR, an inhibitory upstream open reading frame in the 5'-untranslated region of the human hairless gene. We investigated three reportedly unrelated Turkish multigeneration families with MUHH. Using direct sequencing of U2HR we were able to identify the c. 2T>A (p.M1K) mutation in one index patient of each family. The mutation cosegregates perfectly with the disease in all members of the families. To our knowledge, this is the first time that a mutation in U2HR has been identified in families from the Middle East. The observation of a common mutation is suggestive of a possible founder effect.