A syndrome manifested by brittle hair with morphologic and biochemical abnormalities, developmental delay and normal stature

The authors present 2 affected sibs, a male and a female, with unaffected parents and a sib from a small remote northern Mexican village. The syndrome includes mental deficiency, brittle hair with a decreased cuticular layer and an apparently collapsed cortex. The patients' hair contains decreased sulfur content and increased concentrations of trace elements as determined by x ray fluorescent spectroscopy.