“…The 47,XYY individual does not show any consistent physical features or characteristic malformations (Kosenow & Pfeiffer 1966), except usually having an adult height greater than that of his parents (Borgaonkar et al 1972). An extra Y chromosome has been reported in males with radioulnar synostosis (Cleveland et al 1969, Elbualy 1969, pectus excavatum , hypertelorism (Abrams & Pergament 1971), talipes equinovarus (Court Brown et al 1964), idiopathic osteoarthropathy (Tzoneva-Maneva et al 1966), genital abnormalities (Balodimos et al 1966, Elbualy 1969, Franks et al 1967, Thorburn et al 1968, Vignetti et al 1964, neurological abnormalities (Daly 1969), congenital cyanotic heart disease (Price 1968), acne (Hustinx & van Olphen 1963, Telfer et al 1968), gynecomastia (Balodimos et al 1966, Voorhees et al 1970, mental retardation , Kelly et al 1967, and various other abnormalities (Forssman 1967, Hustinx & van Olphen 1963, Kelly et al 1967, Kosenow & Pfeiffer 1966, Richards & Stewart 1966, Tannoia et al 1970, Telfer et al 1968. Some clinically normal individuals have also been reported (Borgaonkar et al 1968, Sandberg et al 1961, Stenchever & Macintyre 1969, Wilton & Lever 1967.…”