EPIDERMAL RIDGE configurations (dermatoglyphics) have been of value in diagnosing a variety of disorders associated with chromosomal aberrations1 and other genetically determined disorders.2 In addition, dermatoglyphics have been abnormal in a high percentage of patients with prenatal rubella.3,4 Most of the snydromes reported to be associated with dermatoglyphic abnormalities also include retardation as a feature. However, most mentally retarded individuals cannot be classified as yet into easily separable syndromes. Most are listed as having idiopathic retardation or retardation of unknown etiology. Where more than one retarded individual in a family is recognized, the term "cultural-familial" retardation is applied and partly glosses over medical ignorance. If the idiopathic group of retarded could be subdivided further on the basis of dermatoglyphic characteristics, a useful diagnostic tool would be available to the clinician.
Studies of dermatoglyphics in mentally retarded groups have been carried out previously but the groups of retarded