Free proximal trisomy 21 in the mother and malformation syndrome in the son.
We report on a new case of duplication of the proximal part of the long arm of chromosome 21. The proposita presents normal mental development, no trisomy 21 manifestations; on the contrary, she had a few monosomy 21-like stigmata. She gave birth to a severely malformed infant with a pattern of malformations suggesting a partial 21-monosomy syndrome, but with a 46,XY normal karyotype in his peripheral blood lymphocytes. The findings are explained in the following way: the infant probably had originally a 47,XY,+21q- karyotype like his mother. Post zygotic nondisjunctional events produced a prevalent 46,XY,21q- line responsible for the severe malformations and the normal 46,XY line found in his blood lymphocytes.
Shabtai
F S
FS
Gattegno Research Institute of Human Reproduction and Fetal Development, Hasharon Hospital, Golda Medical Center, Petach Tikva, Israel.
Schwartz
A
A
Klar
D
D
Hart
J
J
Dar
H
H
Kessler
E
E
Halbrecht
I
I
D000015:Abnormalities, Multiple / Q000235:genetics*; D000328:Adult; D002872:Chromosome Deletion; D002891:Chromosomes, Human, Pair 21; D003878:Dermatoglyphics; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D008297:Male; D009630:Nondisjunction, Genetic