Anhidrosis is defined as the absence of perspiration in the presence of an appropriate stimulus such as heat, exercise, or pharmacological agonists. Isolated anhidrosis with normal sweat glands (ANHD) is very rare autosomal recessive anhidrosis. A homozygous missense mutation in ITPR2 has been identified in all affected family members. ITPR2 encodes a Ca2+ release channel in the endoplasmic reticulum.
