Interchange trisomy 9 due to maternal t(6;9) translocation.
The occurrence of interchange trisomy due to a 3:1 malsegregation has been documented in only a few cases with trisomy 21. We describe the first case of interchange trisomy 9 due to a maternal t(6:9) translocation. The patient, a boy neonate who died immediately after birth, had intra-uterine growth retardation, specific craniofacial features including microcephaly with a high forehead, low-set ears, upslanting short palpebral fissures, microphthalmia, bulbous nose and micrognathia, cryptorchidism, cystic kidney and various skeletal anomalies. His phenotype was consistent with that of the trisomy 9 syndrome. Cytogenetic analysis showed his karyotype of 47,XY,-6, + der(6), + der(9)t(6;9)(q27;q21.1)mat. The present report indicates that a very rare interchange mode of a 3:1 segregation can give rise to a live birth with full trisomy 9 in female carriers with reciprocal translocations involving the proximal long arm of chromosome 9.
Ninomiya
S
S
Department of Pediatrics, Okayama University Medical School, Japan.
Narahara
K
K
Yokoyama
Y
Y
Tsuji
K
K
Ito
S
S
Akahori
W
W
Akahori
T
T
Seino
Y
Y
D000328:Adult; D002896:Chromosomes, Human, Pair 6; D002899:Chromosomes, Human, Pair 9; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D008297:Male; D014178:Translocation, Genetic; D014314:Trisomy