The Rubinstein-Taybi syndrome.

The Rubinstein-Taybi syndrome was first described in 1963. The main clinical features are mental retardation, broad thumbs and great toes, a characteristic facies, and a high-arched palate. Rubinstein and Taybi (1963) described 7 cases in the United States. Since then, small groups of patients and single examples of this syndrome have been reported in the United States (Coffin, 1964; Taybi and Rubinstein, 1965; Johnson, 1966; Kushnick, 1966), Canada (Robinson, Miller Cook, and Tischler, 1966), England (Jancar, 1965; Berg, Smith, Ridler, Dutton, Green, and Richards, 1966; McArthur, 1967), France (Job, Rossier, and de Grandprey, 1964), South America (Latuff, Yamin, and Quintero, 1964), and Italy (Principi, 1966). Up to the present, reports of a total of 41 cases have been published, and Rubinstein presented the combined findings of 31 cases at the International Copenhagen Congress on the Scientific Study of Mental Retardation in 1964. It has become clear that this syndrome is a recognizable clinical entity. Berg et al. (1966) and Giroux and Miller (1967) have described in detail the dermatoglyphs of 6 and 19 patients, respectively, with the RubinsteinTaybi syndrome. Berg et al. (1966) observed a low mean ridge count on fingers, an extra triradius on the tip of the thumbs, high frequencies of patterns in the thenar, hypothenar, and third interdigital areas of the palm, and a lateral displacement of the f triradius in the hallucal area with or without an associated e triradius. Giroux and Miller (1967) found patterns in the thenar/interdigital I area of at least one palm in 16 of 18 patients (89%) with Rubinstein-Taybi syndrome compared with 11% in a control sample of 1000 Canadian schoolchildren. Giroux and Miller (1967) also observed a high frequency of patterns in the hypothenar and third interdigital areas of the hand, a high frequency of arches on the digits of the hand, large atd angles, and unusually long and distorted loops in the hallucal area of the feet. Penrose