Two cases of trisomy C6-12 mosaicism with multiple congenital malformations.

This paper is the report of 2 infants with mosaic trisomy for one of the autosomes in the C group; both were mentally retarded and had multiple con- genital malformations.Case Report Case 1.A Japanese girl, born in January 1968, after a normal gestation of 40 weeks, birthweight 3-1 kg., and length 50 cm.The parents were healthy, aged 31 and 37 years at the birth of this child.The elder sister was also healthy.Feeding difficulties and hyperexcitability were apparent during the neonatal period.At the