RT Journal Article SR Electronic T1 Partial 18 trisomy (with 47 chromosomes) resulting from a familial maternal translocation. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 76 OP 78 DO 10.1136/jmg.15.1.76 VO 15 IS 1 A1 Fried, K A1 Bar-Yochai, A A1 Rosenblatt, M A1 Mundel, G YR 1978 UL http://jmg.bmj.com/content/15/1/76.abstract AB A newborn female infant presented with the classical picture of 18 trisomy syndrome. Her karyotyping was 47,XX,+der(18)t(12;18)(q24;q21)mat. The mother was a balanced reciprocal translocation carrier and so too was one of the two maternal uncles of the proposita, indicating that the translocation was already present in one of the grandparents who were not available for examination. This family suggests that triplication of the distal part of the long arm of chromosome 18 is not necessary to produce Edwards' syndrome.