The Authors report the eugenic prediction formulated for a couple whose three babies (two of whom were monozygotic twins) had died as a consequence of the syndrome of Werdnig-Hoffmann. Since the two cases of the MZ twin pair represent a single chance combination at conception, and since the indications from the literature and from the family tree in this case indicate a monomeric genotype of a recessive type, the morbid risk for a fourth affected child has been estimated at 25%.

The occurrence of concordant W. H. syndrome in MZ cotwins is stressed.

No chromosome abnormalities have been revealed by karyotype examination of the parents.

A case of congenital multiple rhabdomyoma of the heart in both of a set of twins of like sex is presented. A separated diamnionic dichorionic placenta was found. However because both twins had the same sex, the same color of eyes, the same blood group and very similar plantar prints pattern they were considered MZ. Twin A died after 10 days becouse of intractable heart failure. Twin B died one hour after birth of hydrops fetalis. The autopsies showed the presence of multiple rabdomyoma in the walls of both hearts and in Twin B a widely patent ductus arteriosus. No other extracardiac anomalies were noted. The diagnosis of rhabdomyoma of the heart, as is usual, was not made. It should be suspected in any infant who shows evidence of cardiac disease. On the other hand, this first case, known so far in the world literature of congenital rhabdomyoma of the heart in both twins could be an important contribution to the knowledge of the nature of this so discussed lesion.

The Authors have investigated by means of the immuno-electrophoretic method the protein composition of the funicular blood of 19 twin-pairs from pregnancies of 5 to 9 months. Monochorionic twins showed a concordant picture, while in 7 of the 14 bichorionic twin-pairs slight differences could be observed, due to the presence in one of the twins of one or two more lines. The Authors put these results in correlation with the hypothesis of a genie control of the production of proteins.

The A. has studied 51 pairs of epileptic twins: 20 were MZ (11 ♂, 9 ♀) and 31 DZ (9 ♂ 12 ♀, ♂♀).

An ereditary aetiology has been found in 65% of cases:

a) by the concordance of 80% of MZ against 35% of DZ. The MZ concordant in the symptomatic form were 62,5% the DZ 14, 5% the MZ concordant in the so-called idiopathic form were 91%, the DZ 50%.

b) by the incidence in one third of the families of a relative with epileptic seizures (3-4,7% against the 0,5% of general population).

Genic information is not specific either for the convulsive form nor for the electroencephalografic dysrythmia which are only some of the phenotypic manifestations of a deeper disturbance. The pathologic gene or genes should act at a metabolic level with a pleiotropic action upon more functions of the nervous system. The genetic action of the major gene is that of an autosomic, dominant one.