Uniparental isodisomy resulting from 46,XX,i(1p),i(1q) in a woman with short stature, ptosis, micro/retrognathia, myopathy, deafness, and sterility

We report on a 43-year-old woman who was referred for evaluation because of minor facial anomalies, myopathy, sterility, short stature, hearing loss, downward slant of palpebral fissures, bilateral ptosis, severe micro/retrog nathia, high arched palate, and scoliosis. Cytogenetic analyses utilizing G TG/CBG bandings showed presence of one i(lp) and one i(1q) without normal c hromosome 1 homologues. Fluorescence in situ hybridization analysis showed hybridization to only two chromosomes, consistent with the G-banded interpr etation of i(1p) and i(1q). To the best of our knowledge, this is the first case of isochromosomes Ip and Iq replacing the two normal chromosome Is. M olecular investigations using markers for chromosome 1 showed inheritance o f only one set of paternal alleles and absence of any maternal alleles in t he patient. The adverse phenotype of the patient may be due to one or more recessive mutations, genomic imprinting, or a combination of both. (C) 1999 Wiley-Liss, Inc.