Background: The phenotypic expression of an additional chromosome 9 causes a very broad clinical spectrum of anomalies. The prognosis for infants with non-mosaic tetrasomy 9p is poor, and they usually die at a very early age.
Case: In this article we present a new case of complete tetrasomy 9p in a newborn girl with multiple dysmorphologic features. Cytogenetic studies were carried out by CBG, GTG, and QFQ chromosome bandings, as well as by fluorescence in situ hybridization (FISH). The cytogenetic findings for the newborn girl showed an extra chromosome interpreted as an isochromosome 9p. The karyotype was characterized as 47,XX,+mar.ish i(9)(p10)(wcp9+). The parental chromosomes were normal.
Conclusions: The karyotype and clinical features of the newborn girl (e.g., typical craniofacial dysmorphism, severe skeletal anomalies, and visceral and genito-urinary malformations), compared with cases reported in the literature, give additional support to a clinical definition of this chromosomal syndrome.
Copyright 2003 Wiley-Liss, Inc.