Maternal transmission of ring chromosome 21.
A psychomotor-retarded infant with minor dysmorphic signs and a karyotype 46,XY,r(21)mat in lymphocytes is reported. The mother is phenotypically normal but shows the same unstable r(21). This is another case demonstrating that a chromosomal aberration does not necessarily lead to infertility by meiotic failure. Nevertheless, segregation of ring chromosomes is problematic for two reasons: mitotic problems of the ring structure itself and synaptic difficulties during the pachytene stage.
Kennerknecht
I
I
Abteilung Klinische Genetik, Universität, Ulm, Federal Republic of Germany.
Barbi
G
G
Vogel
W
W
D002891:Chromosomes, Human, Pair 21; D005260:Female; D006801:Humans; D007223:Infant; D007621:Karyotyping; D008297:Male; D009035:Mothers; D012303:Ring Chromosomes