Maternal isodisomy of chromosome 9 with no impact on the phenotype in a woman with two isochromosomes: i(9p) and i(9q)

We describe a 34-year-old healthy woman with isochromosomes for the short a nd long arm of chromosome 9 who was ascertained because of repeated spontan eous abortions. Molecular analysis demonstrated maternal uniparental isodis omy for the whole chromosome 9, thus the origin of the isochromosomes was m aternal. Because the patient had a normal phenotype, the maternal isodisomy supports the previous assumption that there are no maternally imprinted ge nes on chromosome 9. Am. J. Med. Genet. 87:49-52, 1999. (C) 1999 Wiley-Liss , Inc.