An 11-and-a-half-year-old girl with 45,X karyotype showed signs of accelerated growth and clitoromegaly and was found to have elevated serum T. Fluorescence in situ hybridization was used to confirm her karyotype as monosomy X and absence of the SRY gene.
In this study, we explored potential clinical applications of AF cffDNA by testing its ability to hybridize to DNA microarrays for comparative genomic hybridization (CGH) analysis. cffDNA isolated from 11 male fetuses showed significantly increased hybridization signals on SRY and decreased signals on X-chromosome markers, compared with female reference DNA. cffDNA isolated from six female fetuses showed the reverse when compared with male reference DNA. cffDNA from three fetuses with trisomy 21 had increased hybridization signals on the majority of the chromosome 21 markers, and cffDNA from a fetus with monosomy X (Turner syndrome) had decreased hybridization signals on most X-chromosome markers, compared with euploid female reference DNA.