title: Characterization of an isodicentric Y-chromosome for the long arm in a newborn with mixed gonadal dysgenesis.
abstract: A newborn infant was referred for evaluation because of ambiguous genitalia. Examination of the genitalia revealed a hypospadiac phallus measuring 1.5 cm in length with chordee. Subtle phenotypic features consistent with Turner syndrome were present including hypertelorism, anti-mongoloid slant to the eyes, mild widening of the neck, but no definitive webbing, shield like chest and positive cubitus valgus. A pelvic and renal sonogram confirmed the presence of a uterus and normal-appearing kidneys. There was incomplete fusion of the scrotum. No gonads were palpable within the scrotal sac. The patient was assigned a female gender on the basis of the presence of a uterus, the phenotypic appearance of the genitalia and the malignant potential of the gonads. The cytogenetic findings with QFQ-banding revealed an abnormal karyotype, i.e., mos 46,X,idic(Y) (p11.2)[77]/45,X[29]/46,X,idic(Y) (p11?) [2]/ 47,XY,idic(Y)(p11.2)[2]/47,X,idic(Y)(p11.2), + idic(Y)(p11.2)[1]/46,XY[1]. The presence of an abnormal isodicentric Y-chromosome was evaluated by FISH-technique to ensure a finer characterization than routine methods. The genotype-phenotype correlation could not be established since mosaicisms of highly variable nature can exhibit an unpredictable outcome.
authors.affiliation: Divisions of Genetics, Long Island College Hospital-SUNY Health Science Center at Brooklyn 11201, USA.
authors.forename: B
authors.initials: B
authors.lastname: Kohn
authors.forename: S M
authors.initials: SM
authors.lastname: Kleyman
authors.forename: R A
authors.initials: RA
authors.lastname: Conte
authors.forename: M J
authors.initials: MJ
authors.lastname: Macera
authors.forename: K
authors.initials: K
authors.lastname: Glassberg
authors.forename: R S
authors.initials: RS
authors.lastname: Verma
mesh_terms: D005260:Female; D006060:Gonadal Dysgenesis, Mixed / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007231:Infant, Newborn; D018404:Isochromosomes; D007621:Karyotyping; D012729:Sex Chromosome Aberrations / Q000235:genetics*; D014998:Y Chromosome