[Cytogenetic and clinical aspects of Prader-Willi syndrome].

Two male nonconsanguineous cases (aged 4 years) of Prader-Willi syndrome are clinically and cytologically studied. Both had obesity, marked hypogonadism, reduced head circumference, psychomotor impairment, hypotonia, tooth decay, small hands and feet, immature EEG. Case 1 showed a "de novo" translocation 7;15 and case 2 showed a normal karyotype.