New human double trisomy or tetrasomy.

Several studies have been reported on the cytogenetic analysis of spontaneous abortions (Aspillage et al., 1966; Boue, Boue, and Lazar, 1967; Carr, 1967; Clendenin and Benirschke, 1963; Hall and Kallen, 1964; Inhorn, Therman, and Patau, 1964; Rashad and Kerr, 1965; Singh, Rubinoff, and Carr, 1966; Szulman, 1965; Thiede and Salm, 1964; Thiede and Metcalfe, 1966; Waxman, Arakaki, and Smith, 1967), and the common chromosomal anomalies seen are autosomal trisomies, sex monosomies, triploidy, and tetraploidy. In addition to these there are some rare abnormalities, such as double autosomal trisomies (Carr, 1967; Boue et al., 1967). The present case is an abortus with a modal number of 48 chromosomes, the two extra chromosomes are large acrocentrics belonging to the D group.