6533b855fe1ef96bd12b0737

RESEARCH PRODUCT

Pigmentary mosaicism in hypomelanosis of Ito

Barbara FritzKaren Helene ØRstavikWolfgang KüsterAnna K. NaumovaHelga RehderJürgen W. Spranger

subject

GeneticsMarker chromosomeRing chromosomeAneuploidyBiologymedicine.diseaseMolecular biologyX-inactivationUniparental disomyGeneticsmedicineXISTSmall supernumerary marker chromosomeGenetics (clinical)X chromosome

description

We report on a female with mental and motor retardation, facial dysmorphism, abnormal pigmentation reminiscent to hypomelanosis of Ito (HI), and karyotypic mosaicism involving a small supernumerary marker chromosome. The marker chromosome was defined by fluorescence in situ hybridisation (FISH) as a ring X chromosome with breakpoints in the juxtacentromeric region. FISH analysis showed that the ring does not include the XIST locus at the X-inactivation centre and, therefore, may not be subject to X inactivation. X-inactivation studies with the HUMARA (human androgen receptor) and FMR1 assay showed a skewed X-inactivation pattern (85:15) with preferential inactivation of the paternal X chromosome. These results are discussed with respect to the role of functional disomy of Xp in the pathogenesis of HI.

yearjournalcountryeditionlanguage
1998-11-17Human Genetics
https://doi.org/10.1007/s004390050848