Mutation in KANK2, encoding a sequestering protein for steroid receptor coactivators, causes keratoderma and woolly hair

The combination of keratoderma (thickened palms and soles) with woolly hair should always alert the clinician to the possibility of Naxos or Carvajal syndromes. These two autosomal recessive conditions are caused by mutations in desmosomal proteins, which are critical for cellular adhesion in the skin. Since desmosomes are abundant in the cardiac muscle, these syndromes are also associated with severe heart disease that leads to sudden death at an early age. The authors studied two families with keratoderma and woolly hair without associated heart disease, and identified a mutation in KANK2, which encodes a non-desmosomal protein that controls the transcription of steroid receptor target genes. Mutation in this gene leads to excess activation of the vitamin D receptor, emphasizing its importance in normal hair and skin phenotypes. (By Dr. Yuval Ramot, http://jmg.bmj.com/content/early/2014/03/26/jmedgenet-2014-102346 )