PARTIAL TETRASOMY 9(9PTER-]9Q2101) DUE TO AN EXTRA ISO-DISENTRIC CHROMOSOME

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  • 1 January 1977
    • journal article
    • research article
    • Vol. 20  (2) , 111-114
Abstract
A 3 yr old boy with partial no. 9 tetrasomy is described. The patient showed markedly retarded physical and mental development as well as multiple congenital anomalies. Routine chromosome analysis revealed an extra C-group chromosome. It had a pronounced secondary constriction at the proximal part of its long arm. Based on studies by a variety of banding techniques, the extra chromosome was identified to be an iso-dicentric no. 9 chromosome with inactivation of 1 of the 2 centromeres, the karyotype being 47,XY,+dic(9)(q2101). The value of BrdUrd [bromodeoxyuridine] treatment was emphasized in the detection of a very small piece of euchromatin within a long stretch of constitutive heterochromatin.