Ninomiya S, Narahara K, Yokoyama Y, Tsuji K, Ito S, Akahori W, Akahori T, Seino Y
Department of Pediatrics, Okayama University Medical School, Japan.
Acta Paediatr Jpn. 1994 Oct;36(5):519-21. doi: 10.1111/j.1442-200x.1994.tb03238.x.
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.
