Menkes isease (also called the kinky hair disease or Menkes kinky hair syndrome) is a disorder that affects copper levels in the body. It is characterized by sparse and coarse hair, growth failure, and deterioration of the nervous system. Onset of Menkes syndrome typically begins during infancy. Signs and symptoms of this disorder include weak muscle tone (hypotonia), sagging facial features, seizures, mental retardation, and developmental delay. The patients have brittle hair and metaphyseal widening. In rare cases, symptoms begin later in childhood and are less severe. It is a X-linked recessive disorder, and is therefore considerably more common in males: females require two defective alleles to develop the disease.