1. Vanpraagh S, Trumen T, Firpo A, Bano-Rogriga A, Freid R, McManis B, Engel MA, and Vanpraagh R: Cardiac malformations in trisomy 18: A study of 41 postmortem cases. JAm Coil Cardiol (1989); 13:1586-1597.
2. Musewe NN, Alexander DJ, Teshima I. Smalihorn JF, FreedomRM:Echocardographic evaluation of the spectral cardiac anomalies associated with trisomy 18 and 13. J Am Coil Cardiol (1990); 15:673-677.
3. Balderston SN, Schaffer EN, Washington RL, and Sondheimer HM: Congenital polyvalvular disease in trisomy 18; Echocardiographic diagnosis. Pediatr Cardiol (1990); 11:138-142.

These three papers present a series of patients with trisomy 18 and in one paper, trisomy 18 and 13, who have congenital heart disease. The paper by Vanpraagh, et al. reviews the cardiac malformation detected at autopsy in 41 cases. The papers by Musewe, et al. and Balderston, et al. review the echocardiographic findings in children with trisomy 18 and 13. In the paper by Baiderston, the presence of congenital polyvalvular disease was evaluated in 15 patients with trisomy 18 and the pattern was compared to the echocardiographic findings in 12 infants who had dysmorphic features but not due to a chromosome abnormality.

Comment:
These three papers strongly support the notion that the pattern of heart valve malforrnations in trisomy 18 in particular, is nonrandom and relatively specific. This concept, of course, is not unusual as the nonrandom pattern of heart defects in Down syndrome and Turner syndrome have been documented for years. Ilowever, most textbooks seem to indicate that the pattern of defects in both Trisomy 18 and 13 are simply shunt lesions, ie. VSD, ASD, and patent ductus arteriosis. In Vanpraagh's paper, 93% of patients had a VSD with polyvalvular disease, ie. malformations of more than one valve. In addition, double outlet right ventricle occurred in 4 of the 41 cases indicating the nonrandomness of this unique malformation as a component manifestation of the syndrome. A striking absence of transposition of the great vessels and inversion defects was also noted. The two echocardiographic series continued to document specificity of this combination of VSD with polyvalvular heart disease. In Balderston's series, all trisomy 18 patients had polyvalvular disease with 6 of the 15 having 4 valve involvement.

While these findings have significance in regards to the pathogenic mechanism of heart disease in trisomy syndromes, they are also Important because the nonrandomness may be helpful in both prenatal diagnosis or in the diagnosis of deceased infants who were not able to be karyotyped. In addition, as mentioned above, attempts at genotype/phenotype correlation in future studies of the classic tnsomy 18 syndrome, should include attempts at mapping this specific pattern of polyvalvular disease.