Triple autosomal trisomy in a pregnancy at risk for Bloom's syndrome.

Cytogenetic analysis of the products of conception in a pregnancy at risk for Bloom's syndrome (BS) documented the karyotype 49,XX, +2, +8, +11. Autosomal triple trisomy has previously been reported in abortuses but is exceedingly rare. Other interesting but previously unreported observations made during the present study were the following: BS in a Brazilian individual, the first instance of BS diagnosed in South America; transmission of the BS mutation in Jews that are non-Ashkenazi; a medulloblastoma in the propositus, the first malignant brain tumor reported in BS; and, as in all previously examined pregnancies at risk for BS, non-homozygosity for the BS mutation.