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

We have presented 2 affected sibs-a male and female-with unaffected parents and sib from a small remote northern Mexican village. The syndrome includes mental deficit, brittle hair with 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. Studies are underway to evaluate other apparently similarly affected children from the village where our family originated.